Method	%
Combined hormonal contraceptives	18
Progestogen-only pill	6
Implant/injectable	5
Intrauterine device/system	7
Barrier methods	24
Vasectomy	10
Female sterilization	7
Natural family planning	2
Withdrawal	4
No method	25^a

^a Subcategories: ‘not having sex’, 14; ‘pregnant or trying to conceive’, 3; ‘menopausal/infertile/otherwise sterile’, 6; ‘doesn’t like/doesn’t use contraception’, 1.

Source: Office for National Statistics 2007/8 Omnibus Survey Report No. 37. Contraception and Sexual Health. Office for National Statistics, London. Available at: www.ons.gov.uk and www.statistics.gov.uk.

Evidence-based recommendations on which individuals can safely use each contraceptive method were first published by the World Health Organization (WHO) in 1996, and are updated at 4-yearly intervals [WHO Medical Eligibilty Criteria (WHOMEC)]. This guidance has been further modified specifically for use in the UK by the Clinical Effectiveness Unit (CEU) of the Faculty of Sexual and Reproductive Healthcare (FSRH) of the Royal College of Obstetricians and Gynaecologists (RCOG), and is available in hard copy and online as the UK Medical Eligibility Criteria (UKMEC). Contraceptive methods are categorized according to their balance of risk and benefit in the presence of certain medical and lifestyle conditions (Table 29.2). Health professionals prescribing contraceptive methods are also directed to the National Institute for Health and Clinical Excellence guidelines on LARC published in 2005.

Table 29.2 UK Medical Eligibility Criteria for Contraceptive Use (RCOG Press, London, 2009)

Classification categories

1 A condition for which there is no restriction for the use of the contraceptive method

2 A condition where the advantages of using the method generally outweigh the theoretical or proven risks

3 A condition where the theoretical or proven risks usually outweigh the advantages of using the method

4 A condition which represents an unacceptable health risk if the contraceptive method is used

Contraception

Combined hormonal contraceptives

The CHC was approved for use in Britain in 1961. In recent years, different modes of delivery have been developed, with injectable, transdermal and vaginal methods now available in some countries. Although unlikely to be substantially different from the oral preparation in terms of efficacy and safety, they do provide a wider choice of administration which may help to offset the effects of erratic pill taking.

Combined hormonal contraceptives (CHCs) contain oestrogen, usually ethinyl oestradiol, and a synthetic progesterone (progestogen). Most modern pills contain 20–35 µg ethinyl oestradiol with either a second-generation progestogen [norethisterone, levonorgestrel (LNG) or ethynodiol diacetate] or a so-called third-generation progestogen (gestodene, desogestrel or norgestimate). The newest progestogen, drospirenone, has antiandrogenic and antimineralocorticoid properties. The 20 µg pills are as effective as the 30 µg pills but, not surprisingly, are associated with poorer cycle control (Akerlund et al 1993).

The traditional CHC regimen involves taking a tablet for 21 days with a 7-day break, thus inducing a withdrawal bleed in order to mimic the body’s ‘natural’ pattern. Variations on this theme include the everyday formulations containing dummy pills so that users do not have to remember to stop and start (common in the USA), 84-day preparations reducing the number of expected withdrawal bleeds from 13 to four per annum, and a continuous version aimed at banishing bleeding altogether. Injectable CHCs are administered intramuscularly every 28 days, with 70% of women experiencing a withdrawal bleed 18–22 days after injection. They are in common use in Latin America. Despite the plethora of transdermal hormone replacement options, there is only one contraceptive patch available. The patch is applied weekly for 3 weeks prior to a patch-free week, and may help to reduce nausea in susceptible individuals (Audet et al 2001). The latest addition to the CHC family is a vaginal ring, 54 mm in diameter and 4 mm in cross-section. It is made of a soft, ethylene–vinyl-acetate copolymer, lasts for 21 days with a 7-day break, and appears to confer more favourable cycle control than other preparations. These longer-acting CHCs may improve compliance.

Combined pills are available in monophasic, biphasic and triphasic preparations. Phasic pills were developed in order to reduce the total dose of progestogen and, by simulating the fluctuating pattern of steroid concentrations in the normal ovarian cycle, in an attempt to produce better cycle control. There is no good evidence that cycle control is superior to that achieved by monophasic pills.

Mode of action

CHCs work primarily by inhibiting ovulation. Exogenous oestrogen inhibits the secretion of follicle-stimulating hormone, while progestogens inhibit the development of the luteinizing hormone (LH) surge. The CHC also alters cervical mucus, rendering it hostile to the passage of sperm, and also causes endometrial atrophy.

CHCs are highly effective (Table 29.3). The failure rates associated with all forms of contraception depend on the inherent efficacy of the method, but also on the potential for incorrect or inconsistent use. Since ovulation is inhibited in most women who use the combined pill, failure rates of the method itself are low. However, as inhibition of ovulation depends on reliable pill taking, the overall failure rate of the COC, which includes user failure, is higher.

Table 29.3 Pregnancy rates for birth control methods (for 1 year of use)

Method	Typical use rate of pregnancy (%)	Lowest expected rate of pregnancy (%)
Sterilization
Male sterilization	0.15	0.1
Female sterilization	0.5	0.5
Hormonal methods
Implant (Implanon)	0.05	0.05
Depo-provera injection	3	0.3
Combined pill (oestrogen/progestogen)	8	0.3
Mini pill (progestogen only)	8	0.3
Evra patch	8	0.3
NuvaRing	8	0.3
IUD/IUS
Copper T	0.8	0.6
LNG-IUS	0.1	0.1
Barrier methods
Male condom^a	15	23
Diaphragm^b	16	6
Female condom	21	5
Spermicide (gel, pessary)	29	15
Sponge
Parous women	32	20
Nulliparous women	16	9
Emergency contraception
Levonelle	15
Copper IUD	<5
Natural methods
Withdrawal	27	4
Natural family planning (calendar, temperature, mucus)	25	3
No method	85	85

IUD, intrauterine device; IUS, intrauterine system; LNG, levonorgestrel.

This table provides estimates of the percentage of women likely to become pregnant while using a particular contraceptive method for 1 year. These estimates are based on a variety of studies.

‘Typical use’ rate means that the method was not always used correctly, was not used with every act of sexual intercourse or was used correctly but failed.

‘Lowest expected’ rates mean that the method failed despite being used correctly with every act of sexual intercourse.

^a Used without spermicide.

^b Used with spermicide.

Adapted from Trussel J 2007 Contraceptive efficacy. In: Hatcher RA, Trussel J, Nelson A, Kates W, Stewart F, Kowal D (eds) Contraceptive Technology, 19th edn. Ardent Media, New York.

Contraindications

In an analysis of 25 years of follow-up of 46,000 women who took part in the Royal College of General Practitioners’ (RCGP) Oral Contraceptive Study comparing 517,519 years of pill use with 335,998 years of never-use, the risk of death from all causes was similar in ever-users and never-users of oral contraception (Beral et al 1999). Among current and recent users (within 10 years), the relative risk (RR) of death from ovarian cancer was significantly decreased (RR 0.2), while the risks of dying from cervical cancer (RR 2.5) and cerebrovascular disease (RR 1.9) were increased.

Absolute contraindications to CHC use are listed in Box 29.1. They include either a past history of, or existing, cardiovascular disease, migraine and most liver diseases. Women often describe headaches as migraine. CHCs are contraindicated in migraine which is or may be associated with transient cerebral ischaemia. A recent study designed to investigate the risk between migraine and stroke in young women demonstrated a significant increase in the risk of ischaemic, but not haemorrhagic, stroke in women with a personal history of migraine both with and without aura (classic and simple). Concomitant use of the CHC further increased this risk (Chang et al 1999). It is important therefore to take a clear and detailed history before refusing to prescribe a CHC because the woman has an occasional migraine.

Relative contraindications to CHC use include the following:

• factors which increase the risk of cardiovascular disease or venous thrombosis, such as obesity, smoking, hypertension and family history;

• sex-steroid-dependent conditions, including cancer;

• factors which adversely affect liver function; and

• factors which predispose to arterial wall disease.

Comprehensive discussions and lists of contraindications are available in most textbooks of contraception, and WHOMEC and UKMEC.

Side-effects of combined oral contraception

Debate continues over the increased risk of cardiovascular events in women taking CHCs. Until reliable data are available for non-oral routes of administration, it is sensible to assume that similar risks apply to all methods. Cardiovascular disease is very rare in women of reproductive age. Venous thromboembolism (VTE) is the most common cardiovascular complication of CHC use. Oestrogen and progestogen are both metabolized by the liver and alter the metabolism of most substances, including carbohydrates and lipids. Oestrogens also alter coagulation factors. A reduction in antithrombin III and alteration in platelet function increase the risk of VTE by up to seven-fold. A clear history of thromboembolism is a contraindication to CHCs. A possible history or a very strong family history are indications for investigating haemostasis, particularly circulating concentrations of antithrombin III and the factor V Leiden thrombogenic mutation. Population screening for inherited thrombophilias is not currently considered to be cost-effective.

Studies in the mid-1990s appeared to show a differential risk of VTE between the second- and third-generation progestogens, the latter being associated with double the risk of the former (Bloemenkamp et al 1995, Jick et al 1995, WHO 1995, Spitzer et al 1996). These findings prompted the UK Committee on Safety of Medicines to advise women at risk of thrombosis to avoid third-generation progestogens. Although well designed, criticisms of these studies include prescriber bias (whereby women with cardiovascular risk factors and new users would be more likely to be prescribed a newer brand) and attrition bias (existing users susceptible to VTE would be less likely to be using older brands). Latterly, the 2005 EURAS study, funded and designed as a postmarketing cohort study to demonstrate the safety of the combined ethinylestradiol/drospirenone pill, found an increased incidence of VTE across the categories (including pregnant women and non-pregnant, non-CHC-using women) with no difference between progestogen used (Dinger et al 2007). Whilst the large numbers in the study (58,674 women and 142,475 women-years) lend strength to its findings, data from the pharmaceutical industry must always be viewed with some reservation. Of additional interest was the reported three-fold increase in risk for women with a body mass index (BMI) above 30 compared with women with a BMI of 20–25. Table 29.4 shows the comparison of risk estimates of VTE from the two sources.

Table 29.4 Absolute risk of venous thromboembolism (VTE)

Population	VTE per 100,000 women-years
	Committee on Safety of Medicines 1995	EURAS 2005
Non-pregnant, non-user	5	44
Second-generation progestogen COC	15	80^a
Third-generation progestogen COC	25	99
Drospirenone	–	91
Pregnant non-user	60	291

COC, combined oral contraceptive.

^a Levonorgestrel alone.

Current CEU advice to prescribers acknowledges the continuing debate over progestogens, and suggests that individual risk of VTE should be a governing principle in choice of contraceptive method.

Arterial disease, including myocardial infarction (MI) and cerebrovascular accident, results from the (mainly) progestogen-related alteration to lipid profiles together with the oestrogen-associated changes in blood coagulation. A WHO expert group reviewed the data on MI, stroke and hormonal contraception; the conclusions are as follows (World Health Organization Scientific Group 1998).

Acute myocardial infarction

• Acute MI is uncommon in women of reproductive age.

• Women who have hypertension and who take the COC have an increased RR of MI of at least three times that of women who take the COC and are normotensive.

• Smoking increases the risk of MI by 10 times when compared with COC users who do not smoke.

• There is insufficient evidence to allow any conclusion on whether the risk of MI is influenced by the type or dose of progestogen.

There was no increased risk of mortality due to ischaemic heart disease, either during or after COC use, in the report of the RCGP study (Beral et al 1999). However, two recent meta-analyses reported odds ratios of 1.84 and 2.48 for MI with low-dose COC use compared with non-current use [Baillargeon et al (2006) and Khader et al (2003), respectively], casting some doubt on WHO’s conclusion that the risk of MI is not increased in CHC users who do not smoke or have hypertension or diabetes.

Stroke

• Ischaemic and haemorrhagic stroke are both uncommon among women of reproductive age.

• The risk of ischaemic stroke is increased approximately 1.5-fold in pill users who do not smoke and are not hypertensive. In contrast, the risk of haemorrhagic stroke is not increased in these women until they reach 35 years of age, after which the increasing natural risk of haemorrhagic stroke is magnified by CHC use.

• Hypertension increases the risk of both ischaemic (by three times) and haemorrhagic (10-fold) stroke compared with never-users.

• Smoking increases the risk of ischaemic and haemorrhagic stroke (∞2–3) compared with pill users who do not smoke.

• There is insufficient evidence to determine whether the risk of either type of stroke is influenced by the type or dose of progestogen.

Thus the data are reassuring for haemorrhagic stroke, but the risk of ischaemic stroke is increased by COC use; once again, this is supported by the findings of the RCGP study (Beral et al 1999), in which the RR of death from stroke was significantly increased to 1.9 [confidence interval (CI) 1.2–3.1, P = 0.009]. Ten years after discontinuation of the pill, the risk of death from stroke is no longer elevated. For a useful review of hormonal contraception and cardiovascular risk, see Curtis and Marchbanks (2005).

Cancer

Overviews of the risks and benefits of the COC are dominated by breast cancer. Published data are difficult to interpret because pill formulations and patterns of reproduction (particularly age at first pregnancy) have changed with time. In 1996, the Collaborative Group on Hormonal Factors in Breast Cancer reported a meta-analysis of 54 studies involving over 53,000 women with breast cancer and 100,000 control subjects. The group concluded that use of the COC was associated with a small increase in breast cancer, and that the increased risk persisted for 10 years after discontinuation of the pill. The RCGP study (Beral et al 1999) was also reassuring in this respect, since the risk of dying from breast cancer was not significantly increased among current or recent (within 10 years) COC users. The relationship between the pill and breast cancer is difficult to explain because the risk appears to increase soon after exposure, does not increase with duration of exposure and returns to normal 10 years after discontinuation. It has been suggested that starting to use the pill may accelerate the appearance of breast cancer in susceptible women (i.e. late-stage promotion of existing dysplasia). It is also possible that women using the pill have their tumours diagnosed earlier, although it is difficult to explain why a tendency to earlier diagnosis would persist for years after discontinuation. In the large meta-analysis, the risk of breast cancer was also increased among current users of both the progestogen-only pill (RR 1.17) and Depo-provera (RR 1.07), although the number of women using progestin-only methods was small. These findings strengthen the argument for increased detection rather than late-stage promotion of breast cancer. Nonetheless, a biological effect of hormonal contraception has still not been ruled out.

Incident data from a large cohort study from the RCGP (Hannaford et al 2007) has shown significantly lower rates of cancers of the large bowel, rectum, uterine body, ovaries and tumours of unknown origin in ever-users of the COC compared with never-users. There was no material difference between groups for breast cancer, and only small, non-statistically-significant increases in cancers of the lung, cervix and central nervous system. Taken together, there was an absolute rate reduction of any cancer in ever-users of 45 per 100,000 women-years.

Conversely, women taking the COC for more than 8 years did have a significantly increased risk of cervical cancer.

An increase in the risk of squamous carcinoma of the cervix (RR 1.3–1.8) has been recognized for some time. Recent extensive analysis of existing data detected an RR of 1.9 for 5 or more years of COC use (90% CI 1.69–2.31), declining after cessation of use and, like breast cancer, no different from that of never-users at 10 years after discontinuation (International Collaboration of Epidemiological Studies on Cervical Cancer 2007). The relationship is complicated by a number of confounding factors such as patterns of sexual behaviour and the likelihood of having cervical smears. Whether the national introduction in 2008 of vaccination for girls against human papilloma virus types 16 and 18 will have an effect on these figures remains to be seen. An increase in the risk of the much less common cervical adenocarcinoma (RR 2.1, increasing to 4.4 after 12 years of use) has also been demonstrated (Ursin et al 1994).

Other side-effects

Approximately 2% of women become clinically hypertensive after starting the pill. The incidence increases with age and duration of use, obesity and family history. It does not, however, appear to be increased in women with a history of pregnancy-induced hypertension.

An increased risk of gallstones is only significant during the early years of pill use.

A few women develop chloasma on the CHC; both oestrogen and progestogen contribute to this. The chloasma may be slow to fade after the hormones are stopped.

Minor side-effects are most common during the first 3 months of use, and often lead to discontinuation of the method. More common problems include breakthrough bleeding (BTB) or spotting, nausea, breast tenderness, acne and loss of libido. Many of these resolve with time. If side-effects persist after 4 months, it is often worth changing the brand of pill, opting for a lower dose of oestrogen or a different type of progestogen, or changing the mode of delivery. Pills containing antiandrogens are particularly useful for acne.

While the CHC, in general, improves menstrual bleeding patterns, one common reason for presentation to a gynaecologist is BTB. BTB is common during the first three cycles of use. Persistence beyond 3 months may be a result of poor compliance or a coexisting gynaecological disorder such as cervical ectropion (probably more common among COC users), or cervical or uterine polyps. If pelvic examination is normal, it is worth trying a formulation containing a higher dose of oestrogen or a different type of progestogen. After 3 months’ use of a pill containing 50 µg ethinyl oestradiol, the bleeding will often settle and the woman can then resume a lower-dose pill. Alternatively, the vaginal ring may confer improved bleeding patterns. If bleeding persists, try stopping hormonal contraception altogether; if it does not resolve, it should be investigated as intermenstrual bleeding, i.e. by endometrial biopsy and hysteroscopy.

Benefits of combined oral contraception

The CHC confers a number of health benefits. Withdrawal bleeds are usually more regular, lighter and less painful, and the CHC is often the treatment of choice for women with irregular heavy periods (resulting from anovulatory dysfunctional uterine bleeding), premenstrual syndrome, dysmenorrhoea and endometriosis, as ovarian suppression can be achieved without the need for additional contraception (in contrast to danazol). A Cochrane review also concluded that the CHC can improve acne (Arowojolu et al 2009). These benefits can improve compliance significantly (Courtland Robinson et al 1992).

CHC use is associated with a 70% reduction in the risk of endometrial cancer, which may be maintained for up to 15 years after discontinuation (Weiderpass et al 1999). There is a similar duration-dependent reduction in the risk of ovarian cancer (RR 0.64, 95% CI 0.57–0.73) in ever-users compared with never-users (Riman et al 2004), which probably acts through the inhibition of ovulation and lasts for at least 10 years after discontinuation.

Significant numbers of unplanned pregnancies result from women stopping the pill for a ‘break’. There is no evidence that breaks in pill taking reduce the long-term risks. It is not necessary to stop the CHC before planning a pregnancy. There is no evidence of any adverse effect on the fetus of CHC use prior to conception, neither is exposure during pregnancy associated with increased risk of fetal malformation.

Fertility is restored after a delay of 1–3 months, although some women take longer to resume normal cycles. So-called ‘post-pill amenorrhoea’ is almost always associated with cycle irregularity before starting the pill or with coincidental factors associated with secondary amenorrhoea, such as weight loss or stress.

Progestogen-only contraceptives

Progestogen-only contraceptives (POCs) are much less commonly used than CHCs. However, POCs are available in a wider variety of systems, including pills, implants, long-acting injectables and hormone-releasing IUDs.

The mechanism of action of POCs depends on the dose of steroid administered. High doses, such as depot medroxyprogesterone acetate (DMPA), inhibit ovulation. Low doses only inhibit ovulation inconsistently, and the effect varies between individuals. All POCs affect both the quantity and physical characteristics of cervical mucus, reducing sperm penetrability and transport. All have an effect on the endometrium, probably compromising implantation. The recent addition of a 75 µg desogestrel progestogen-only pill (Cerazette^®) combines inhibition of ovulation in 97% of users with the oral route of administration.

The absence of oestrogen in this group of hormonal methods is associated with an absence of cardiovascular risks including VTE. In a case–control study undertaken by WHO (World Health Organization Collaborative Study of Cardiovascular Disease and Steroid Hormone Contraception 1998), there was no significant increase in the risk of MI, stroke or VTE associated with use of oral or injectable progestogen-only methods.

The progestogen-only pill (POP or mini-pill) is a useful alternative for women who like the convenience of the COC but for whom oestrogen is contraindicated. Not only does the POP not contain oestrogen, but the dose of progestogen is significantly lower than in equivalent combined preparations. The POP is still a good alternative for women with medical contraindications to the COC, such as migraine and hypertension. It is often advocated for women with diabetes who are at increased risk of cardiovascular disease and who may find that insulin requirements fluctuate with COC cycles. However, the COC is not absolutely contraindicated for diabetic women without long-term complications, whose diabetes is well controlled and for whom pregnancy would be a disaster. The most common indication for POP use in the UK used to be for breastfeeding women, since the POP (unlike the CHC) does not interfere with either the quantity or constituents of breast milk. However, due to its mode of action and likely increased efficacy, the newest POP has wider potential. It is no longer considered necessary to advise women routinely to change from the COC to the POP when they reach the age of 35 years, since the combined pill, in the absence of risk factors for cardiovascular disease, is very safe.

Mode of action

While Cerazette inhibits ovulation in over 90% of cycles, approximately 50% of classical POP users continue to ovulate and menstruate regularly. In these women, the POP works by altering cervical mucus and probably by interfering with implantation. If follicle development is inhibited completely, amenorrhoea results (10–20% of women).

Side-effects

The mode of action of the POP explains its side-effects. Erratic bleeding is the most common cause for discontinuation of the pill; approximately 20% of women will stop using it for this reason.

Follicular growth without ovulation is associated with an increased incidence of functional ovarian cysts. Up to 20% of women using the POP will have a cyst identifiable by ultrasound. Most are symptomless and nearly all resolve spontaneously. A woman found to have a symptomless ovarian cyst should be reviewed after her next menstrual period.

POP use is associated with a slightly increased risk of ectopic pregnancy. Some 2% of pregnancies among POP failures will be ectopic, perhaps as a result of an effect of the progestogen on tubal motility. Since Cerazette inhibits ovulation in almost all cycles, the theoretical risk of ectopic pregnancy is less.

Due to its mechanism of action (50% of women continue to ovulate) and its relatively short half-life (approximately 19 h), the classical POP has a higher failure rate than the COC (see Table 29.3), with users of the established varieties having a 3-h window within which to remember to take their pill. This failure rate is dependent on age and is almost as low as the COC in women aged over 35 years. However, the ovulation-inhibiting Cerazette can be taken in much the same way as the COC with a 12-h window, making it a suitable and reliable choice for younger women as well. There is no direct evidence for advising women who weigh more than 70 kg to take two pills each day.

Injectable progestogens

Long-acting injectable progestogens are available in two forms: DMPA or Depo-provera (150 mg IM every 12 weeks) and norethisterone oenanthate (200 mg IM every 8 weeks). The latter is seldom used in the UK.

Worldwide, DMPA is a popular method of contraception used by some 9 million women in over 90 countries. DMPA appears to exert a powerful protective effect against endometrial cancer with an RR of 0.2. No association has been described between DMPA use and the risk of ovarian cancer, which is surprising if the protective effect of the COC is due to the inhibition of ovulation. The slight increase in the risk of breast cancer among users of both the POP and DMPA identified in the large meta-analysis (Collaborative Group on Hormonal Factors in Breast Cancer 1996) may be due to detection bias; however, there are some concerns that progestins alone may be associated with a real increase in risk.

Depo-provera is a highly effective (Table 29.3) long-acting method which only requires the user to attend for injection four times a year. It inhibits ovulation, and 80% of women are either amenorrhoeic (40%) or have very scanty, infrequent periods (40%) after 1 year of use. The remaining 20% of women will have prolonged regular or, more usually, irregular bleeding episodes, and approximately 2% of women will present, often to a gynaecologist, with troublesome menorrhagia. After excluding any pathology, the most effective treatment of menorrhagia is oestrogen (Fraser 1983), and it is most easily given as one packet of the COC. If bleeding problems persist, an alternative method of contraception should be considered.

Other significant long-term side-effects include:

• weight gain; up to 6 kg during the first 2 years of use;

• a delay in the resumption of fertility of up to 1 year or more after cessation of use; and

• a reduction in bone mineral density (BMD).

BMD has been shown to plateau after an initial decrease in the first year of use. Current studies (flawed by the use of surrogate measures of bone health, methodological errors, comparison of heterogeneous populations and varying sites of BMD measurements) show a 2–3% decrease in BMD in the first year of DMPA use, slowing in subsequent years. BMD is gradually regained following discontinuation of DMPA, and appears to be similar to that of never-users in adults at 30 months after the last injection (Gbolade et al 1998). Similar findings in adolescents were reported at 12 months after discontinuation of the method (Scholes et al 2005). To date, there is no good evidence for an increased risk of fractures.

The Committee on Safety of Medicines (2006) made the following recommendations in the light of the existing evidence:

• in adolescents, DMPA may be used as a first-line contraception but only after other methods have been discussed with the patient and considered to be unsuitable or unacceptable;

• in women of all ages, careful evaluation of risks and benefits of treatment should be carried out in those who wish to continue use for more than 2 years; and

• in women with significant lifestyle and/or medical risk factors for osteoporosis, other methods of contraception should be considered.

This advice is in line with the UKMEC.

Progestogen-only implants

Progestogen-only, subdermal implants are available worldwide and are used by millions of women. The original LNG-releasing Norplant^® comprised six rods; modern implants with a preloaded applicator and only one or two rods are much easier to insert and remove. Jadelle^® is identical to Norplant but has two rods. It is approved for 5 years. Implanon^®, a single rod, is approved for 3 years of use in the UK, and consists of an ethylene–vinyl-acetate copolymer core containing 68 mg etonorgestrel. The rate-limiting membrane allows an initial release rate of approximately 60–70 µg/day, slowly decreasing to 30–40 µg/day at the end of the second year and 25–30 µg/day at the end of the third year.

Although the implants are not difficult to insert, removal can occasionally be troublesome, particularly if the rods are inserted subcutaneously rather than subdermally. Failure rates are extremely low (Table 29.3), and all failures are due to the method as implants do not depend on compliance. The dose of progestogen is sufficient to inhibit ovulation in every cycle throughout the 3 years. Cervical mucus is scanty and allows poor sperm penetration.

Approximately 20% of women experience amenorrhoea with Implanon. A further 60% may experience erratic bleeding or no effect on their usual menstrual cycle. The remaining 20% will request removal on the basis of unacceptable menstrual disturbance. Fertility resumes as soon as the implants are removed. Bleeding irregularity is the most common side-effect and reason for removal, but others include acne, hirsutism, headache, mood change, and weight gain or bloating (i.e. the metabolic side-effects of progestogens). For a useful review of contraceptive implants, see Glasier (2002).

Intrauterine devices and systems

The IUD is a cheap, effective long-acting method of contraception. It exerts a local inflammatory reaction within the cavity of the uterus which probably, acting through tubal and uterine fluid, interferes with the viability of both sperm and eggs. It also inhibits implantation. Inert devices are no longer recommended or marketed, but some older women do still have them in utero. Modern copper-containing devices are licensed for use over 5–10 years. After a woman reaches 40 years of age, the device need not be changed and can be removed 1 year after the last menstrual period. Copper IUDs consist of a plastic frame with copper wire round the stem and, in some cases, copper caps on the arms. The surface area of the copper determines the lifespan and efficacy of the device. IUDs with a surface area of copper of less than 200 mm² are associated with higher pregnancy rates and are no longer recommended for long-term use. A frameless IUD (Gynefix^®) comprises six copper beads threaded on to a nylon line. The beads at the top and bottom are crimped to hold them on the line, and the string has a knot at the proximal end which is embedded, using a special inserter, into the myometrium, anchoring it in place.

The LNG-releasing device [known as a system (IUS) to distinguish it from copper IUDs] has been licensed in the UK since 1995 under the trade name Mirena^®. It consists of a column of LNG within a rate-limiting membrane wrapped around the stem of a Nova-T frame. A total dose of 52 mg LNG is released at a rate of 20 mg/day. It is licensed for 5 years for contraception. A small amount of LNG is absorbed systemically and can give rise to androgenic side-effects such as acne. Menstrual bleeding is significantly reduced, with periods being replaced by light spotting and eventually, in many women, amenorrhoea. In the classic study of the effects of the LNG-IUS on menstrual blood loss (Andersson and Rybo 1990), women complaining of menorrhagia experienced a reduction in blood loss of 86% at 3 months and 97% at 12 months after LNG-IUS insertion. Mirena is now widely used in the UK, and is licensed for the management of menorrhagia (Royal College of Obstetricians and Gynaecologists 1999) and as the progestogen component of hormone replacement therapy. A frameless equivalent of the IUS, Fibroplant^®, is the most recent modification of this technology with a silastic sleeve, suspended on a thread which is anchored into the uterine fundus with a knot.

Side-effects

Perforation is a rare event (one in 1000 insertions); if it is recognized early, it may be possible to remove the IUD via the laparoscope before adhesions form. For this reason, it is probably wise to see women for follow-up to check the tails of the device within 4–6 weeks of insertion.

Expulsion occurs in 3–10% of women in the first year of use and is related to parity, age, type of IUD and timing of insertion. The incidence of both expulsion and perforation is influenced by the skill of the person inserting the device. Both complications are increased with postpartum insertions which, according to the UKMEC, should be scheduled no earlier than 4 weeks after delivery.

The risk of pelvic infection among IUD users has been greatly exaggerated. In countries where IUDs are inserted under appropriate sterile conditions, the risk of pelvic infection is only increased for 20 days after insertion. Women infected with gonorrhoea or chlamydia have an increased risk of infection if an IUD is inserted compared with uninfected women, but the risk of salpingitis is not increased compared with infected women who are not undergoing IUD insertion. Even women who are human immunodeficiency virus (HIV) positive do not appear to have an increased risk of complications, including infection, associated with IUD insertion, and there is no evidence that IUD use increases viral shedding (Grimes 2000). In addition, there is no evidence for an increased risk of infertility among past or current IUD users. However, if an IUD user becomes pregnant, the probability of that pregnancy being ectopic is greater than that for women using no contraception or another method because the IUD does not prevent tubal implantation. In women at risk of pre-existing infection, IUD insertion can be covered with a broad-spectrum antibiotic. Routine screening for infection may be more cost-effective in services where the background rate of infection, especially with chlamydia, is high.

The most common reason for discontinuation of the copper IUD is menorrhagia. The local inflammatory response, together with increased production of prostaglandins, causes both menorrhagia and dysmenorrhoea. All IUDs are removed by steady traction on the tail of the device. Occasionally, the string snaps off during removal. It is sometimes possible to remove the device with a pair of artery forceps or a specially designed IUD remover, but some IUDs, particularly the old inert devices, appear to become deeply embedded in the endometrium and may only be removed under general anaesthetic. It is not known if an IUD without its tails can be left in the cavity of the uterus for a woman’s lifetime without causing any problems. There is a small risk of actinomycosis but the inconvenience of admission to hospital for a general anaesthetic may outweigh this. It is probably best discussed with the individual concerned.

Natural family planning

Although few couples in the UK use so-called ‘natural methods of family planning’ (NFP), these methods are common in some parts of the world. All involve ‘periodic abstinence’ (i.e. avoidance of intercourse during the fertile period of the cycle). Methods differ in the way in which they recognize the fertile period. The simplest is the calendar or rhythm method, in which the woman calculates the fertile period according to the length of her normal menstrual cycle. Others use symptoms which reflect fluctuating concentrations of circulating oestrogen and progesterone, themselves reflecting follicular development, impending ovulation and completed ovulation. The mucus or Billings method relies on identifying changes in the quantity and quality of cervical and vaginal mucus as a reflection of the steroid environment. As circulating oestrogens increase with follicle growth, the mucus becomes clear and stretchy, allowing the passage of sperm. With ovulation and in the presence of progesterone, mucus becomes opaque, sticky and much less stretchy or disappears altogether. Intercourse must stop when fertile-type mucus is identified, and can start again when infertile-type mucus is recognized. Progesterone secretion is also associated with a rise in basal body temperature (BBT) of approximately 0.5°C. The BBT method is thus able to identify the end of the fertile period. Other signs and symptoms such as ovulation pain, position of cervix and degree of dilatation of the cervical os can also be used to help define the fertile period. A personal fertility monitor called Persona, which measures urinary oestrogen and LH using a dipstick, can help to identify the fertile period but does not significantly reduce the number of days of abstinence required and is expensive. Whatever method is used, all rely on a period of abstinence and many couples find this difficult. Failure rates are high (Table 29.3) and most of the failures are due to conscious rule breaking. Perfect use of the mucus method is, in fact, associated with a failure rate of only 3.4%. There is no evidence that accidental pregnancies occurring among NFP users, which are conceived with ageing gametes, are associated with a higher risk of congenital malformations.

Lactational amenorrhoea method

Breast feeding delays the resumption of fertility, and it still has a major impact on fertility rates in developing countries. It has been calculated that breast feeding provides more than 98% protection from pregnancy during the first 6 months post partum if the mother is fully or nearly fully breast feeding and has not yet experienced vaginal bleeding after the 56th day post partum. Lactational amenorrhoea method (LAM) guidelines advise that as long as the baby is less than 6 months old, a woman can rely on breast feeding alone until she menstruates or until she starts to give her baby significant amounts of food other than breast milk. Prospective studies of the LAM confirm its effectiveness (Perez et al 1992).

Barrier methods

The male condom remains one of the most popular methods of contraception in the UK. It is cheap, widely available over the counter and, with the exception of the occasional allergic reaction, is free from side-effects. Use of the condom increased significantly with concern over the spread of HIV and acquired immunodeficiency syndrome as it is the only method of contraception which also prevents sexually transmitted infections (STIs).

In addition to protection against STIs, use of the condom, and diaphragm, is associated with a significant reduction in cervical disease (Celentano et al 1987). Female barrier methods are less popular. The diaphragm and cervical cap must be fitted by a professional and do not confer the same degree of protection against STIs/HIV. The female condom, by virtue of covering the mucus membranes of the vagina and vulva, is more effective in preventing STIs but has a high failure rate and low acceptability.

Spermicides alone are not a very effective method of contraception and are only recommended for use with a condom (most of which are already lubricated with spermicide) or diaphragm. Nonoxynol 9 (N-9) is a spermicidal product sold as a gel, cream, foam, film or pessary for use with diaphragms or caps. Many male condoms are lubricated with N-9. As frequent use of N-9 might increase the risk of HIV transmission, women who have multiple daily acts of intercourse or who are at high risk of HIV infection should not use N-9. For women at low risk of HIV infection, N-9 is probably safe (Van Damme et al 2000, www.who/int).

Emergency contraception

Hormonal preparations and the IUD can be used to prevent pregnancy after intercourse has taken place. In the UK, one hormonal preparation is available: Levonelle (LNG 1.5 g). It is licensed for use within 72 h of intercourse, but women should be encouraged to present as soon as possible for treatment. It is, in any case, very difficult to estimate the efficacy of any emergency contraceptive (EC) since the true risk of pregnancy for any one individual cannot be calculated with any degree of certainty, and many of the ‘failures’ are pregnancies which are, in fact, conceived with an act of intercourse which occurred earlier in the cycle or some time after the act for which EC was sought. Levonelle is now available off prescription from pharmacists.

IUD insertion is more effective (Table 29.3) and can be used up to 5 days after the estimated day of ovulation, which may be significantly longer than 5 days after the act of intercourse. The FSRH advise that intrauterine EC should be offered to all women presenting after unprotected intercourse, in the absence of contraindications, as the gold standard method. If the woman does not wish to continue with the method, it can be removed with the next period or when an alternative method has been established.

The mechanism of action of hormonal EC remains unclear. It has been shown to delay or impair ovulation in some 50% of users, but there is no good evidence that it will inhibit implantation. Neither is there any contraceptive/contragestive effect once implantation is complete. Conversely, the IUD has a toxic effect on gametes, reduces the number of sperm reaching the fallopian tubes and, if inserted after fertilization has taken place, inhibits implantation, resulting in a higher level of efficacy (Table 29.3). The LNG-IUS is not recommended as an emergency contraceptive.

Recent efforts to find a more effective, orally active emergency contraceptive with fewer side-effects have resulted in trials of the antiprogesterone mifepristone (Task Force on Postovulatory Methods of Fertility Regulation 1999). Since mifepristone is known to inhibit both ovulation and implantation, it is likely to be more effective than LNG, but its properties as an abortifacient limit its further development at present.

Sterilization

Over 42 million couples worldwide, the majority of whom live in developing countries (particularly China and India), rely on vasectomy. More than three times that number rely on female sterilization. In Britain, surgical methods of contraception are declining in popularity. Between 1998 and 2008, vasectomy fell from 12% to 10% and female sterilization fell from 12% to 7%. The more pronounced decline in female sterilization is probably due to the introduction of long-acting reversible methods.

Female sterilization

Female sterilization usually involves the blocking of both fallopian tubes either by laparotomy or minilaparotomy or, more commonly, by laparoscopy. It may also be achieved by bilateral salpingectomy (or by hysterectomy when there is coexistent gynaecological pathology such as hydrosalpinx or fibroids) or by hysteroscopic techniques.

Minilaparotomy and laparoscopic female sterilization are probably equally safe and effective; however, the latter allows sterilization to be done as a daycase procedure and is recommended by the RCOG (2004a) as the method of choice in the UK. Minilaparotomy is most commonly used when sterilization is performed immediately post partum as, at that time, the uterus is large, the pelvis is very vascular and the risks of laparoscopy are increased.

A variety of techniques exist for occluding the tube, as follows.

Efficacy

A report from the US Collaborative Review of Sterilization (Peterson et al 1996) prospectively evaluated over 10,000 women who underwent sterilization in nine US cities. The women were followed-up for between 8 and 14 years. The failure rate varied with age and the method of tubal occlusion. The 10-year lifetable cumulative probability of pregnancy for all ages combined (18–44 years) ranged from 7.5 pregnancies per 1000 procedures (for unipolar coagulation and postpartum partial salpingectomy) to 36.5 pregnancies per 1000 procedures (for clips). Failure rates were highest for women under the age of 28 years, with 52 pregnancies per 1000 procedures for spring clips. Women considering laparoscopic sterilization in the UK should be advised that the lifetime risk of failure is one in 200.

In the UK, a device called Essure^® is the only licensed product available for hysteroscopic sterilization. It is a 4 cm, inert, nickel-titanium coil containing polyester fibres, designed to be inserted into each tubal ostia under direct vision and to cause fibrosis sufficient to have occluded the tubes by 3 months post procedure. A recent UK cohort study comparing Essure (developed as an ‘office-based’ procedure) with laparoscopic sterilization reported high levels of patient satisfaction (Duffy et al 2005). Longer-term assessment of efficacy and safety is awaited.

A number of chemical agents have been tested for their ability to occlude the fallopian tube when instilled into the tube either directly or transcervically into the uterus. The quinacrine pellet is the only one ready for large-scale use. The method involves insertion of a 252 mg quinacrine pellet into the uterine cavity through a modified IUD inserter passed through the cervical canal. Two insertions, 1 month apart, are made during the follicular phase of the cycle. Occlusion is caused by inflammation and fibrosis of the intramural segment of the tube. Efficacy can be increased by adding adjuvants such as antiprostaglandins or by increasing the number of quinacrine insertions. A failure rate of 2.6% after 1 year of follow-up has been reported (Hieu et al 1993). The method is cheaper than surgical sterilization, avoids the use of any anaesthesia and can be performed by non-medical personnel. Large numbers of women in Asia and Pakistan have been sterilized using this method. However, although quinacrine is widely used for malaria prophylaxis, the safety of quinacrine sterilization has not yet been determined and some question the ethics of using a technique which has not been approved in developed countries. Toxicology studies are presently underway.

Counselling for sterilization

Most couples seeking sterilization have been thinking about the operation for some considerable time. The initial consultation should include a discussion of:

• the procedure involved;

• the failure rate;

• the risks and side-effects;

• the possibility of wanting more children;

• which partner should be sterilized;

• the issue of reversibility. Despite careful counselling, a few couples will inevitably request reversal of sterilization. This is most likely to happen with remarriage. Immediate postpartum or postabortion sterilization is more likely to be regretted and should be avoided if possible. Although as many as 10% of couples regret being sterilized, only 1% of these will request reversal; and

• alternative long-acting methods of contraception which are reversible and equally effective, such as contraceptive implants.

The RCOG (2004a) recommends that verbal counselling advice should be backed up by accurate impartial printed information which the couple may take away.

Reversal of female sterilization is more likely to be successful after occlusion with clips which have been applied to the isthmic portion of the tube, since only a small section of tube will have been damaged. Patients should realize that reversal involves laparotomy, does not always work (microsurgical techniques are associated with approximately 70% success) and carries a significant risk of ectopic pregnancy (up to 5%). Ovulation should be confirmed and a normal semen analysis should be obtained from the partner before reversal is undertaken. Reversal is unlikely to be available on the National Health Service (NHS) in most parts of the UK.

The history should include the following:

• the reason for the request: some women seek sterilization as a cure for menstrual dysfunction, sexual problems or abdominal pain;

• gynaecological and obstetric history, and relevant medical histories of both partners;

• ages, occupations and social circumstances of both partners;

• numbers, ages and health of their children;

• previous and current contraception and any problems experienced. Some women request sterilization because they are unable to find any other acceptable method of contraception; this is not a good reason for sterilization;

• the stability of the relationship and the possibility of its breakdown; and

• the quality of the couple’s sex life.

It is seldom possible to arrange sterilization for a particular time of the cycle, and women should be told to continue using their current method of contraception until their operation. It is not necessary to stop the combined pill before sterilization as the risk of thromboembolic complications is negligible.

If an IUD is in situ, it should be removed at the time of sterilization, unless the operation is being done at mid-cycle and intercourse has taken place within the previous few days, in which case it can be removed after the next menstrual period.

Complications

Immediate complications

• The operation carries a small operative mortality of less than eight per 100,000 operations. In a large series from the USA (Peterson et al 1983), the most common cause of death was anaesthesia. In the UK, laparoscopic sterilization is commonly performed under general anaesthesia, but local anaesthesia is an acceptable alternative.

• Vascular damage or damage to bowel or other internal organs may occur during the procedure and is usually recognized at the time of operation. Nevertheless, patients should be aware that the rare possibility of a laparotomy and longer hospital stay does exist.

• Gas embolism.

• Thromboembolic disease is rare, but is more likely if the procedure is done immediately post partum.

• Wound infection.

• Postoperative pain is common because of local tissue ischaemia and necrosis at the site of occlusion of the tube. It can be reduced by the use of local tubal anaesthesia.

Long-term complications

• Menstrual disorders: women who stop using the combined pill will almost certainly notice that their periods become heavier, perhaps more painful and less predictable, and they should be warned of this. In contrast, women whose previous method of contraception was an IUD will notice an improvement in their bleeding patterns. Although a review of the evidence concluded that female sterilization does not alter ovarian activity or menstruation (Gentile et al 1998), a number of studies have demonstrated an increased incidence of gynaecological consultation and an increased incidence of hysterectomy among women who have been sterilized (Hillis et al 1998). Bearing in mind the inevitable changes in menstrual bleeding patterns associated with advancing age and with discontinuation of the combined pill (the most commonly used method of reversible contraception), it may be that women who have been sterilized are more likely to seek hysterectomy, or more willing to accept it, if they are already incapable of further child bearing.

• The term ‘post-tubal sterilization syndrome’ was coined to describe a variety of symptoms that have been reported after sterilization and which women may attribute to the procedure. These symptoms include abdominal pain, dyspareunia, exacerbation of premenstrual syndrome or dysmenorrhoea, and emotional and psychosexual problems. Laparoscopy fails to demonstrate any pathology. A review of the literature (Gentile et al 1998) concluded that sterilization is not associated with an increased risk of these problems, except among young women sterilized before 30 years of age in whom the symptoms may sometimes be a manifestation of regret.

• Psychological and psychosexual problems are rare; when they do arise, they tend to do so in those who have had problems before sterilization. Many studies, in fact, report a better mental state after sterilization.

• Bowel obstruction from adhesions is a very rare complication.

• Ectopic pregnancy is a well-recognized complication of sterilization. In the US Collaborative Review (Peterson et al 1997), the risk was influenced by age and the method of occlusion. The 10-year cumulative probability of ectopic pregnancy for all ages combined ranged from 1.5 (for postpartum partial salpingectomy) to 17 (for bipolar coagulation) pregnancies per 1000 procedures, while for women aged less than 30 years, the figures were 1 and 33, respectively. Women should be advised that if they miss a period and have symptoms of pregnancy, they should seek medical advice urgently.

Vasectomy

Vasectomy involves the division or occlusion of the vas deferens to prevent the passage of sperm. The vas is exposed through a small skin incision, and ligated or occluded with small silver clips or by unipolar diathermy with a specially designed probe which can be passed into the cut end of the vas.

Excising a small portion of the vas makes reversal more difficult and probably does not increase the effectiveness unless at least 4 cm is removed. It does allow histological confirmation of a correct procedure in difficult cases, but is not routinely recommended. Interposing the fascial sheath between the cut ends or looping the cut ends of the vas back on itself may increase effectiveness. The RCOG (2004a) recommends that fascial interposition or diathermy should accompany division of the vas which, on its own, is not an acceptable technique in terms of the failure rate. This recommendation, although the opinion of experts, is not supported by scientific evidence, and the relative efficacy of any one method of occlusion and efficacy probably depends most on the skill of the surgeon.

The ‘no-scalpel’ vasectomy (NSV), developed in China in 1974, is now quite widely used. It makes use of specially designed instruments for isolating and delivering the vas through the scrotal skin, and substitutes a small puncture for the skin incision. Any of the standard methods of occlusion may be used. NSV is quick and associated with a lower incidence of infection and haematoma. A comparison between NSV and conventional vasectomy in Thailand reported a complication rate of 0.4% vs 3.1% (Nirapathpongporn et al 1990).

Percutaneous injection of sclerosing agents, such as polyurethane elastomers, or occlusive substances, such as silicone, is also being used in China. The technique avoids any skin incision, the silicone plug is said to be easily removed, and pregnancy rates of 100% up to 5 years after vasectomy reversal have been claimed.

The rate at which azoospermia is achieved depends on the frequency of ejaculation. In the UK, seminal fluid is examined after 12 and 16 weeks, and if sperm are still present, usually monthly thereafter. When sperm are absent from two consecutive samples, the vasectomy can be considered complete; until then, an alternative method of contraception must be used. Approximately 3% of men do not become azoospermic and the vasectomy has to be redone.

Some men complain of a dull ache in the scrotum which may be exacerbated by sexual excitement and ejaculation. The symptoms are probably due to distension and granuloma formation in the epididymis and vas deferens. Pain may also result from scar tissue forming around small nerves. Chronic pain associated with progressive induration, tubular distension and granuloma formation in the epididymis may require excision of the epididymis and obstructed vas deferens.

Concerns about a possible link between vasectomy and cardiovascular disease were raised in the 1970s following reports that vasectomy increased atherosclerosis in monkeys, perhaps as a consequence of increased levels of autoantibodies. Several large studies, including a cohort study in the USA of over 10,000 vasectomized men, failed to substantiate increased rates of 98 diseases (McDonald 1997).

Cancer

Two studies from the USA and Scotland suggested an increased risk of testicular cancer following vasectomy. However, a large cohort study of over 73,000 men in Denmark (Moller et al 1994) demonstrated no increase in the incidence of testicular cancer among men who had a vasectomy.

A number of reports from the USA have also suggested an increased risk of prostate cancer following vasectomy. No known biological mechanism can account for any association or causal relationship between vasectomy and prostate cancer. A 1998 systematic review of 14 studies published from 1985 to 1996 (Bernal-Delgado et al 1998) reported a summary risk estimate of 1.23 (95% CI 1.01–1.49), but the authors concluded that there was evidence against a causal relationship. An editorial from the US National Cancer Institute, commenting on a large US population-based study which found no effect of vasectomy on prostate cancer (Peterson and Howards 1998), concluded that vasectomy does not appear to cause prostate cancer or there is only a relatively weak relationship.

Reversal

Reversal of vasectomy is technically feasible in many cases, with patency rates of almost 90% being reported in some series. Pregnancy rates are much less (up to 60%), perhaps as a result of the presence of antisperm antibodies.

Abortion

After the Abortion Act was passed in the UK in 1967, there was a rapid rise in the number of abortions, which reached a plateau in the late 1980s. Since then, there has been a gradual rise in the numbers each year, with 198,500 abortions being performed in England and Wales and 13,700 being performed in Scotland in 2007. The abortion rate in Britain (13 per 1000 women aged 15–45 years in Scotland and 18 per 1000 in England and Wales in 2007) is relatively low compared with many other developed countries. Nevertheless, at least one-third of British women will have had an abortion by the age of 45 years. The rate of teenage pregnancy (including both childbirth and abortion) in Britain is one of the worst in Europe. The Teenage Pregnancy Independent Advisory Group was formed in England 1998 to investigate teenage pregnancy and to make recommendations based on their findings. Their annual reports and the Government’s response can be found at www.everychildmatters.gov.org.

Legal aspects

In the UK, it is illegal to induce an abortion except under specific indications, as defined by law. The conditions of the 1967 Abortion Act state that abortion can be performed if two registered medical practitioners, acting in good faith, agree that the pregnancy should be terminated on one or more of the following grounds.

• The continuance of the pregnancy would involve risk to the life of the pregnant woman greater than if the pregnancy were terminated.

• The termination is necessary to prevent grave permanent injury to the physical or mental health of the pregnant woman.

• The pregnancy has NOT exceeded its 24th week and the continuance of the pregnancy would involve risk, greater than if the pregnancy were terminated, of injury to the physical or mental health of the pregnant woman.

• There is a substantial risk that if the child were born it would suffer from such physical or mental abnormalities as to be seriously handicapped.

In 1990, the law was amended to reduce the upper limit from 28 to 24 weeks of gestation, reflecting the lowering of the limits of fetal viability resulting from advances in neonatal care. An exception was made in the case of a fetus with severe congenital abnormality incompatible with life (e.g. anencephaly), in which case there is no upper limit.

The 1967 Abortion Act does not apply to Northern Ireland where abortion is only legal under exceptional circumstances, such as to save the life of the mother.

The law recognizes that some doctors have ethical objections to abortion. Doctors who do have objections are obliged to refer women to a colleague who does not hold similar views.

Over 98% of induced abortions in Britain are undertaken on the grounds that the continuance of the pregnancy would involve risk to the physical or mental health of the pregnant woman.

Provision of services

In Scotland and north-east England, over 90% of abortions are performed in NHS hospitals, while in other areas of England, the majority are carried out in private clinics or by charities. In Scotland, abortion accounts for over 22% of the inpatient gynaecological workload and is thus a major issue for gynaecologists. Some hospitals have dedicated services which are quite separate from the general gynaecological service, and which are staffed by experts who are more sensitive and sympathetic. While this has obvious advantages for individual patients and is recommended as best practice by the RCOG (2004b), the approach risks separating abortion from other aspects of reproductive health care and removing it from general gynaecological training. Without exposure during their training to the issue and to women who are seeking abortion, doctors may become increasingly reluctant to be involved with the provision of services, as they are in the USA.

Counselling

Faced with the news of an unintended pregnancy, many women are emotionally devastated and the decision to have a pregnancy terminated is never an easy one. In the UK, the Committee on the Working of the Abortion Act (the Lane Committee), reporting in 1974, recommended that every woman should have the opportunity to have adequate counselling before deciding to have her pregnancy terminated. Abortion counselling should provide opportunities for discussion, information, explanation and advice in a manner which is non-judgemental and non-directional.

By the time most women see a gynaecologist, they have already seen one doctor (usually their general practitioner) and are certain of their decision. However, in order to satisfy themselves that there are grounds for termination, gynaecologists should nonetheless discuss the reasons why the pregnancy is unwanted and whether the woman is absolutely certain about her decision, since uncertainty may be more likely to lead to regret. The woman should be encouraged to think of the practical and emotional consequences of all the possible options of abortion, continuing with the pregnancy and adoption.

Not all doctors are sympathetic, and women who are seen to have conceived because of a true method failure are more likely to get a sympathetic hearing. Many women feel that they have to ‘make the case’ to the gynaecologist for having their pregnancy terminated, and some will claim method failure even when they have not been using contraception. One in five women who have had an abortion will present for another at some time in their lives. Women who seem to use abortion as a method of contraception and present again and again probably need psychiatric help and not a punitive approach from the gynaecologist.

In the UK, approximately 1% of women will present too late for legal abortion. These, and some of those who choose to have the baby, will need information about adoption and benefits, and sometimes referral to social services.

The gynaecologist should provide information about the procedure involved, offering, where available and appropriate, a choice of surgical or medical methods to women below 12 weeks of gestation. The possible complications and long-term side-effects of the abortion should also be discussed, together with the implications for future pregnancies. Verbal discussions should be supported by written information, and confidentiality should be emphasized.

Future contraceptive plans are usually discussed before the abortion is carried out. Although this may not be the best time, it may be one of the few opportunities to discuss contraception as many patients do not attend for follow-up.

Assessment

After it has been decided that there are grounds for abortion, it is important to make a careful medical assessment of the woman.

• The medical history should pay particular attention to conditions such as asthma which may influence the choice of method of abortion.

• The stage of gestation should be determined by menstrual history and transvaginal or transabdominal ultrasound scan. Whilst acceptable to establish gestation, pelvic examination for this purpose alone has generally been superseded by ultrasound, as the former is felt to be less accurate and seldom detects ectopic pregnancy or missed miscarriage.

• Whether the service chooses to screen for genital tract infection, particularly chlamydia, or simply to treat everyone with prophylactic antibiotics will depend on the background incidence of infection in the local population, but one or other is essential. If screening is chosen, it is emphasized that antibiotic therapy should be started before abortion is performed.

• Women considered to be at high risk of hepatitis B or HIV should be offered screening with appropriate counselling. Women who refuse screening should be treated as high risk during the abortion procedure.

• Cervical screening should be offered in accordance with national screening policies.

• Blood should be collected for measurement of haemoglobin concentration, and the blood group should be determined. All women who are Rhesus negative should be injected with anti-D immunoglobulin prior to or within 48 h of the abortion to prevent the development of Rhesus isoimmunization.

Techniques of abortion

In general, the earlier the abortion is done, the safer it is. Mortality and morbidity associated with the procedure increase with the gestation of the pregnancy at the time of termination. The risk of major complications doubles when termination is carried out at 15 weeks of gestation compared with 8 weeks.

The method of choice depends on gestation, parity, medical history and the woman’s wishes. The RCOG (2004b) state that, as a minimum, all services must be able to offer abortion by one of the recommended methods for each gestation band, but that services should ideally be able to offer a choice.

Early-first-trimester abortion (≤9 weeks)

Surgical

Vacuum aspiration has been the method of choice for early surgical termination of pregnancy in industrialized countries for over 20 years. Dilatation and curettage requires more cervical dilatation and is associated with a significantly higher complication rate, including uterine injury, and a higher incidence of retained products of conception and adverse future reproductive outcome (Henshaw and Templeton 1993).

Vacuum aspiration can be performed under either local paracervical block or general anaesthesia. Some evidence suggests that the use of general anaesthesia increases the risk of the procedure. In the USA, the mortality rate is two to four times greater when general anaesthesia is used rather than local anaesthesia for first-trimester abortion. Preoperative treatment with a cervical priming agent has been shown to reduce the risk of haemorrhage and genital tract trauma associated with vacuum aspiration. Prostaglandins, bougies and mifepristone are all effective, but prostaglandins (gemeprost 1 mg vaginally or misoprostol 400 µg vaginally, both 3 h before surgery) probably achieve their effect more quickly. Pretreatment of the cervix adds to the cost of the procedure and may be difficult to organize when abortion is performed as a day case. As cervical trauma is more common in women under the age of 17 years and uterine perforation is associated with increasing parity and increasing gestation, efforts to arrange cervical ripening should be concentrated on young women (aged <18 years), highly parous women and those presenting at a gestation of greater than 10 weeks.

A curette of up to 10 mm internal diameter is passed through the cervix, and the contents of the uterus are aspirated using negative pressure created by a pump. It is advisable to use the smallest diameter curette which is adequate for the gestation; most gynaecologists use an 8 mm curette at 8 weeks, 10 mm at 10 weeks, etc.

Vacuum aspiration at this stage of pregnancy is extremely safe and effective. Failure is more likely to occur before 7 weeks of gestation when it is possible to miss the fetus with the curette. For this reason, medical methods or a rigorous protocol for early surgical abortion are recommended. The mortality from vacuum aspiration in the first trimester is less than approximately one in 100,000; considerably less than the maternal mortality from continuing pregnancy.

Medical

Medical abortion is available to women in the UK up to 63 days of amenorrhoea (9 weeks of gestation) using a combination of the antiprogesterone mifepristone 600 mg orally followed 36–48 h later by the prostaglandin gemeprost 1 mg vaginally. Mifepristone is a synthetic steroid which blocks the action of progesterone by binding to its receptor. It also binds to the glucocorticoid receptor and blocks the action of cortisol. When mifepristone is used alone, complete abortion only occurs in approximately 60% of pregnancies. The rate of complete abortion rises to over 95% if a prostaglandin is given 36–48 h after the administration of mifepristone. The antiprogesterone itself stimulates some uterine contractility, but mainly works by greatly enhancing the sensitivity of the myometrium to the tocolytic effect of prostaglandins. A 200 mg dose of mifepristone is as effective as 600 mg and, given with an oral prostaglandin misoprostol (which is not licensed for abortion) 800 µg vaginally 36–48 h later, makes for a much cheaper and now commonly used regimen.

Offered the choice of method, approximately 30% of women in Scotland prefer medical abortion. Women often choose the medical method because it avoids an anaesthetic in most cases, and because they feel more in control of the situation. It is, however, a two-stage procedure which other women find a disadvantage. The incidence of serious complications is probably similar to that associated with surgical abortion, but because 95% of women need neither anaesthesia nor instrumentation of the uterus, large randomized trials may eventually show medical abortion to be safer. Not all women are suitable for medical abortion; the contraindications are shown in Box 29.2.

There are very few side-effects following administration of mifepristone. The fetus is usually passed within 4 h of prostaglandin administration, and this is accompanied by bleeding and pain. The bleeding is usually described as being like a very heavy period, although rarely (<1%) there may be very heavy bleeding requiring resuscitation. Nulliparous women and those with a history of dysmenorrhoea are more likely to experience severe pain, and 10–20% of women may need opiate analgesia. The rest will cope with paracetamol. Prostaglandin synthetase inhibitors, such as aspirin or mefanamic acid, should be avoided for obvious reasons. A few women will abort at home in response to mifepristone with variable amounts of bleeding and discomfort.

Bleeding can continue for up to 20 days after the abortion, although most women have usually stopped after 10 days. The total amount of blood lost is similar to that occurring at the time of vacuum aspiration.

All women should be given an appointment for follow-up approximately 2 weeks after administration of the prostaglandin. This visit is absolutely essential for those (approximately 30%) who have not passed an identifiable fetus and/or placental tissue while in hospital. Although ongoing pregnancy occurs in only 1% of cases, evacuation of the uterus will be necessary in approximately 2–5% of cases because of incomplete or missed abortion. These figures are no different from those associated with surgical abortion.

The risk of fetal malformation following mifepristone alone or in combination with prostaglandins is not known. Women should be clearly advised that medical abortion is a two-stage procedure, and that it is not possible to have a change of heart after taking mifepristone and before prostaglandin administration. Women who seem even remotely uncertain about abortion should certainly not be offered the medical method. In the event of failed medical abortion and therefore ongoing pregnancy, the patient must be strongly advised to have vacuum aspiration, although babies born to the few women who have chosen to continue with the pregnancy after medical abortion has failed have been normal.

Late-first-trimester abortion (9–13 weeks)

At this stage of pregnancy, the method of choice used to be vacuum aspiration as failure rates for medical methods were thought to be higher. However, a randomized trial of women between 9 and 13 weeks of gestation to either medical or surgical abortion found completed abortion rates to be comparable (Ashok et al 2002). This is reflected in the RCOG guidelines (2004b) which detail an effective medical regimen for this purpose. Surgical evacuation is a straightforward procedure up to 12 weeks of gestation, but thereafter requires specific experience and is not undertaken in many NHS settings. Although late-first-trimester abortion remains an extremely safe procedure, blood loss and other complications increase as gestation advances. It is important, therefore, to refer the woman for abortion promptly after the decision to terminate the pregnancy has been made.

Mid-trimester abortion

Second-trimester abortion accounts for 10–15% of all legal abortions in the UK. While many are done because of fetal malformation, it is often the women who are least able to cope with an unwanted pregnancy, particularly the very young, who first present at this time.

It is possible to induce abortion at this stage of pregnancy either medically or surgically. Surgical dilatation and evacuation (D&E) is the method of choice in the USA, but in the UK, its use is confined largely to gynaecologists in private practice. It may be necessary to dilate the cervix up to a diameter of 20 mm before the fetal parts can be extracted. D&E is a safe procedure in skilled hands, but if complications such as haemorrhage and perforation of the uterus are to be avoided, surgeons should be adequately trained. D&E should be preceded by cervical preparation, as described earlier.

Medical abortion for women presenting at greater than 15 weeks of gestation can be performed with mifepristone 600 or 200 mg orally, followed 36–48 h later by either gemeprost 1 mg vaginally every 3 h, up to a maximum of five pessaries, or by misoprostol 800 µg vaginally then 400 µg orally 3-hourly to a maximum of four oral doses.

Most women find the procedure painful and distressing, and require opiate analgesia. Evacuation of the uterus is necessary in approximately 30% of women who retain all or part of the placenta.

Abortion beyond 18 weeks of gestation is rare and is usually for pregnancies complicated by severe fetal malformation. Particularly distressing for both the mother and the staff, these late abortions are often effectively managed with vaginal prostaglandins in combination with mifepristone, with intra-amniotic urea or fetal intracardiac injection of potassium to minimize the chance of a live birth.

Follow-up

Anti-D immunoglobulin should be given to all non-sensitized Rhesus-D-negative women following any therapeutic abortion. Written advice about possible post-treatment symptoms, particularly those associated with infection, together with advice about what action to take should be given to patients before discharge home. All women should receive contraceptive advice and, if appropriate, supplies before going home. Ovulation can return within 20 days following abortion, and contraception should be started at the time of abortion if possible. All should be given a follow-up appointment within 2 weeks, either with the clinic which carried out the abortion or with a suitable alternative doctor. At follow-up, a pelvic examination should confirm complete abortion and the absence of infection. Discussion should include contraceptive advice and postabortion counselling, if required.

Complications

Mortality risk

In the UK, a woman is more likely to die in childbirth than she is to die from a complication of abortion (British Medical Association 2007). Although maternal mortality is, fortunately, extremely rare following abortion, the incidence of major complications, haemorrhage, thromboembolism, operative trauma (uterine perforation and cervical trauma) and infection is approximately 2%. The main factors affecting the incidence of complications in the RCGP study (Frank 1985) undertaken in the early 1980s were the place of operation (complications were less common when the abortion was done in a private hospital), gestation, method of abortion, sterilization at the time of operation and smoking habits.

Incomplete abortion

The most common complication following abortion is the persistence of placental and/or fetal tissue. Up to 5% of women undergoing first-trimester medical abortion will require surgical evacuation of the uterus within the first month. The incidence of incomplete abortion and ongoing pregnancy after vacuum aspiration rises as the gestation increases.

The occurrence of bleeding at 2 weeks after a medical or surgical abortion is not, in itself, an indication to evacuate the uterus. Ultrasound scans often show residual trophoblastic tissue even in women who have stopped bleeding. Although an ultrasound scan of the uterus and the measurement of human chorionic gonadotrophin in plasma may be helpful in diagnosing an ongoing pregnancy, the decision to evacuate the uterus should be made on clinical grounds (i.e. continued heavy or persistent bleeding from a bulky uterus in which the cervix is still dilated). The majority of women with an incomplete or missed abortion will pass the residual tissue with time if they are prepared to be patient. The belief that all women with an incomplete abortion had a high risk of intrauterine infection until the uterus was evacuated probably stemmed from the time when illegal abortion was common.

Minor complications

Some 10% of women undergoing abortion present to their general practitioner during the 3 weeks following the procedure with a variety of complaints related to the abortion. Lower abdominal pain, vaginal bleeding and passage of clots or trophoblastic tissue are relatively common and usually only require reassurance. It is, however, important to exclude infection. Established pelvic inflammatory disease with pyrexia, abdominal pain and offensive vaginal discharge occurs in approximately 1% of women whatever method of abortion is used.

Many women feel tearful and emotional for a few days following the abortion. However, many studies have demonstrated a significant improvement in psychological well-being by 3 months post abortion compared with before abortion (Adler et al 1990, 1992). Reviewers of existing literature have concluded that adverse psychiatric outcomes are observed in a minority of women following abortion, which are most often (although not exclusively) an exacerbation of morbidity predating the procedure, and that women denied abortion often experience significant ongoing resentment (Dagg 1991, Thorp et al 2002). Lack of a supportive partner, ambivalence regarding their decision or membership of a cultural group that forbids abortion are, unsurprisingly, risk factors for adverse psychological sequelae.