1: CONTRACEPTION

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CHAPTER 1 CONTRACEPTION

Introduction
Combined oral contraceptive (COC)
Combined contraceptive transdermal patch
Progestogen-only pill (POP)
Injectable progestogens
Progestogen-releasing implant (Implanon)
Postcoital (emergency) contraception
Condom
Diaphragm
Intrauterine contraceptive device (IUCD)
Intrauterine progestogen-only system (Mirena/IUS)
Natural birth control
Sterilisation
Hormonal contraception in the perimenopause
Postpartum contraception

INTRODUCTION

The practice nurse with family planning training may play a significant role, e.g. diaphragm-fitting, pill-teaching and coil-checking.

Methods of contraception include: combined pills, progestogen-only pills, injectable and implanted progestogens, condoms, diaphragms, intrauterine contraceptive devices, natural methods and surgical sterilisation. Other methods, e.g. coitus interruptus, the use of spermicides alone and contraceptive sponges, are not discussed in this chapter as their failure rates are relatively high. Long-acting reversible contraceptive methods (IUD, IUS, depot injections and implants) are more cost-effective than the COC. All contraceptives, other than condoms, are available free on prescription.

Discussion of ‘safe sex’ and the prevention of HIV infection and other sexually transmitted infections should be part of the routine advice given to the sexually active. This is particularly important when counselling the very young. (Surveys suggest that about 50% of all under-16-year-old females have had intercourse.) ‘Safe sex’ means sex in which the exchange of bodily fluids is eliminated. ‘Low-risk sex’ means wet kissing, oral sex without ejaculation, and sexual intercourse using a condom. The use of the condom should be promoted in addition, often, to the main contraceptive. The advantages of fidelity within a sexual relationship, and, in the very young, of postponing intercourse, should be discussed in a non-judgemental way.

Always consider the possible STI risk when discussing contraception, particularly in the following situations:

• Young patient/early in sexual career.
• Emergency contraception request.
• IUCD request.
• TOP request.
• Assault.
• Patient symptomatic (pain, discharge, ulcers, intermenstrual bleeding, postcoital bleeding, breakthrough bleeding on COC, contact bleeding on taking cervical smear).
• Multiple partners or recent change of partner.
• Partner symptomatic.

FRASER GUIDELINES

A doctor must consider the following issues when the patient is under 16 years old:

• Whether the patient understands the potential risks and benefits of the treatment and the advice given.
• The value of parental support. Doctors must encourage young people to inform parents of the consultation and explore the reasons if the patient is unwilling to do so. The patient must be assured of confidentiality.
• Whether the patient is likely to have sexual intercourse without contraception.
• Whether the patient’s physical or mental health is likely to suffer if s/he does not receive contraceptive advice or supplies.
• Whether the patient’s best interests would require the provision of contraceptive advice or supplies, or both, without parental consent.

COMBINED ORAL CONTRACEPTIVE (COC)

STARTING THE COC

Assessment

History.

Ask about/think about possible contraindications.

Absolute contraindications

• DVT or emboli.
• Heart disease (valvular or ischaemic).
• Hypertension (>160/100).
• Hyperlipidaemia.
• Focal or severe migraine/TIAs.
• Cancer of the breast/cervix.
• From 4 weeks before to 2 weeks after major surgery.
• Rare:

– liver disease (active)
– polycythaemia; sickle cell anaemia
– porphyria
– hydatidiform mole (recent)
– hyperprolactinaemia
– diabetic complications.

Relative contraindications

• Family history of arterial disease.
• Diabetes.
• Hypertension (>160/95).
• Heavy cigarette smoking.
• Excessive weight.
• Age. (Smokers should stop the pill at the age of 35 years; there is no definite upper age limit in healthy non-smokers.)
• Common migraine.

Examination.

Check:

• weight
• BP
• smear status.

Management

The following points should be considered and discussed, if appropriate:

Failure rate.

The failure rate is in the range 0.1–3/100 women-years.

How to start the COC

• Start on day 1 to 5 and no extra contraceptive precautions are necessary.
• Alternatively, start after day 5 and take extra precautions for the first 7 days. (The COC may in fact be started on any day of the cycle, provided that extra precautions are taken for 7 days, but initial bleeding will be unpredictable.)
• Take 1 tablet daily for 21 days. Subsequent courses repeated after 7-day pill-free interval.

Ovulation.

The COC stops ovulation; ‘periods’ are light withdrawal bleeds.

Risks of taking the COC

• Smoking >15 cigarettes per day increases the risk of coronary heart disease by three times.
• Vascular disease in general is increased by about three times. (There is no statistically significant increased risk of myocardial infarction among pill users, unless they also smoke.)
• Hypertension develops in 5% of pill users after 5 years.
• There is a 1.2 relative increase of carcinoma of the breast during use and for 10 years after stopping the COC; this does not appear to be related to duration of use. It is more than counterbalanced by the protective effect against cancers of the ovary and endometrium.

Side-effects

• Breakthrough bleeding. (This usually settles within 2–3 months.)
• Nausea, breast tenderness, weight gain, PMT, bloating (fluid retention), depression, vaginal discharge (secondary to cervical erosion), headaches, reduced libido, chloasma.

Gastrointestinal upset.

Vomiting and severe diarrhoea lead to reduced hormone absorption. Take extra contraceptive precautions for the period of illness and for 7 days afterwards.

Prescribing.

Ideally, use the lowest strength of pill that does not cause breakthrough bleeding. The dose of oestrogen (ethinyloestradiol) should normally be no more than 20–35μg. Ideally, a preparation with the lowest oestrogen and progestogen content which gives good cycle control and minimal side-effects should be chosen.

Low strength preparations (containing ethinyloestradiol 20μg) are particularly appropriate for women with risk factors for circulatory disease.

Standard strength preparations (containing ethinyloestradiol 30 or 35μg) are appropriate for standard use.

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Reproduced with permission from Guillebaud J 2004 Contraception: your questions answered, 4th edn. Churchill Livingstone, Edinburgh

Phased preparations are particularly appropriate for women who either do not have withdrawal bleeds or who have BTB with monophasic pills.

Common choices for women free of risk factors for arterial disease under the age of 30 years are pills delivering levonorgestrel or norethisterone. Women with risk factors for arterial disease or those who are relatively intolerant of pills containing levonorgestrel or norethisterone may do better on a pill containing a third-generation progestogen.

Pills containing the third-generation progestogens (desogestrel, gestodene or drospirenone) can also be useful for women who have side-effects (e.g. weight gain, acne, headaches, depression, breast symptoms and BTB) with other progestogens. Desogestrel and gestodene increase the risk of DVT. In 100 000 women, the approximate number developing a DVT in 1 year is:

• for women taking a pill containing desogestrel or gestodene, 25
• for women taking one of the other COCs, 15
• for women who are pregnant, 60
• for other healthy women not taking a COC, 5.

Women with risk factors for venous disease (including women with a BMI of >30, those with marked varicose veins, those with an immobility problem and those with a family history of DVT) should not use these pills.

What to do if a pill is missed

The most risky pills to miss are those in the first or last week of the pack, as the 7-day pill-free interval is lengthened.

• If pills are missed, take the last missed pill as soon as possible and then resume the normal schedule.
• If the missed pills are in week 3, the pill-free interval should be omitted.
• If pills are missed in week 1 (because the pill-free interval has been extended), emergency contraception should be considered if UPSI occurred in the pill-free interval or in week 1.
• Use condoms or abstain from sex for 7 days if:

– two or more 20 μg pills have been missed
– three or more 30 μg pills have been missed.

Drug interactions.

Liver enzyme inducers, e.g. phenytoin, carbamazepine, griseofulvin and topiramate, increase the metabolism, and thus elimination in the bile, of both oestrogen and progestogen. If the patient is on a liver enzyme inducer, start a higher dose pill (≥50 μg oestrogen). Consider ‘tricycling’ (i.e. taking 3 or 4 packets of monophasic tablets without a break followed by a short tablet-free interval of 4 days).

Tip

Certain broad-spectrum antibiotics (e.g. ampicillin, tetracyclines and griseofulvin) alter gut flora and reduce oestrogen absorption. Take extra precautions for the duration of treatment and for 7 days afterwards. Long-term treatment with antibiotics does not require extra precautions, as resistant flora develop.

Follow-up.

The first follow-up is at 3 months. Subsequent follow-ups are at 6–12 month intervals.

Check:

• new risk factors
• smoking status
• weight change
• BP
• smear status.

Management of subsequent problems

Breakthrough bleeding

• Ask about COC compliance or vomiting (prevents COC absorption).
• Liver enzyme inducing drugs (e.g. phenytoin) can cause BTB.
• Consider pregnancy.
• Check for cervical lesions if BTB is persistent.
• (Chlamydia may cause a blood-stained discharge/BTB.)

If BTB persists for >2–3 months after starting the COC, try an equivalent pill with a different progestogen (see pill ladder, p. 5) or a pill with a higher oestrogen or progestogen content or change to a triphasic pill.

Absent withdrawal bleed.

Absent withdrawal bleeds are harmless in themselves. Consider pregnancy. Consider changing to a pill with a lower dose of progestogen or to a triphasic pill.

Side-effects.
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