Chapter 31 Fertility, preconception care and pregnancy
PRECONCEPTION CARE
There is solid scientific evidence that infant health is inextricably linked to the health of the women who bear them, especially regarding preconception care.1 Preconception care takes place prior to conception and focuses on the reduction of conception-related risk factors and increasing healthy behaviours. It can be said that preconception care epitomises the naturopathic principle to address the cause, not just the symptom, of illness. By ensuring health issues are addressed in both partners prior to conception, the aim is to improve the health of the infant at birth in a way that even early prenatal care can not.2 Ideally, preconception care involves both partners as some risk factors affect both males and females. Furthermore, involving both partners may help promote equal involvement in the preparation for a major life transition. As with all naturopathic treatments, preconception care incorporates a holistic approach and, as such, supports the physical and psychological health of both partners.
The nature of a preconception care plan will differ between couples. For ease of understanding, preconception care can be categorised into two broad categories: health promotion and disease attenuation. Health promotion preconception care describes couples who have not yet attempted conception and have no diagnosed illnesses, but would like to ensure optimum health before their baby is conceived. Disease attenuation preconception care, in contrast, applies to couples with current diagnosed health conditions, or who have already had unsuccessful attempts to conceive. There may be some crossover between these two categories and, once disease attenuation has been addressed, it is quite common to incorporate health promotion into the plan prior to conception (see Figure 31.1). However, these are general guides only and the approach to the treatment plan should always be patient-centred, with the time and level of intervention required for each category determined based on couples’ needs. As such, it is important to remind couples that, although many achieve conception soon after they commence attempting, for others patience is required.
Infertility and subfertility
Impaired fertility affects approximately one in six couples.3 In young, healthy couples, the probability of conception in one reproductive cycle is typically 20 to 25%, and in 1 year it is approximately 90%; however, this success rate can decline rapidly due to various age-related or health factors.3
Reproductive specialists use strict definitions of infertility.4 Clinical infertility in a couple is defined as the inability to become pregnant after 12 months of unprotected intercourse. However, consensus is building that the diagnosis of clinical infertility should also be considered after six cycles of unprotected sex in women over 35 years of age.5 Clinical infertility may also be considered when the female is incapable of carrying a pregnancy to full term. At this time further investigation becomes warranted to establish whether there are physical conditions hindering conception and, if so, what intervention may be appropriate. Infertility is not necessarily analogous to subfertility, which is often caused by other underlying conditions such as endometriosis or polycystic ovarian syndrome.
Causes of infertility and subfertility
Infertility can be considered to be primary or secondary. Couples with primary infertility have never been able to conceive, while secondary infertility is defined as difficulty conceiving after already having conceived (and either carried the pregnancy to term or had a miscarriage).4 Secondary infertility is not considered as a diagnosis if there has been a change of partners.4
Infertility may also be more broadly grouped into categories of sterility or relative infertility. Sterility can arise from various predominantly non-treatable underlying disorders involving lack of eggs (menopause, radiation damage or some autoimmune diseases); lack of sperm (infectious causes or immature sperm); fallopian tube obstruction (endometriosis, surgical or due to infection such as chlamydia) or hysterectomy. In contrast, infertility may be caused by other factors (see Table 31.1). Male causes of infertility include defective sperm production and/or insemination difficulties.6 Female causes include ovulation factors (anovulation or infrequent ovulation), tubal damage, uterine factors such as adhesions, and cervical mucus ‘hostility’ (commonly due to an immunological defect).6
Table 31.1 Common causes of infertility in males and females
| MALE | FEMALE |
|---|---|
| Low sperm count | Non-specific immune factors |
| Low percentage of progressively motile sperm | Irregular ovulation (e.g. polycystic ovarian syndrome) |
| Disorders of sperm morphology | Steroid hormone imbalance (may be influenced by insulin, thyroid function, stress, adiposity or exposure to hormone disrupting compounds) |
| High degree of abnormality on sperm | Hostile endometrial environment (may be influenced by hormonal imbalance, structural abnormalities, fibroids, infection or immunological factors) |
| Chromosome fragmentation | Genetic variations (such as MTHFR polymorphism) |
Source: Adapted from Speroff and Fritz 20054
CONVENTIONAL TREATMENT
The conventional approach to preconception care does not differ greatly from the naturopathic approach. The focus is on increasing the general level of health and ceasing unhealthy behaviours. The factors identified as areas of concern for preconception care include chronic diseases, infectious diseases, reproductive issues, genetic/inherited conditions, medications and medical treatment, and personal behaviours or exposures.2 Of these issues, a number have proposed clinical practice guidelines. Folic acid supplementation, for example, is considered essential to reduce the incidence of neural tube defects in the fetus, and thus supplementation ideally begins 3 months prior to conception.2 Prevention of congenital defects due to rubella infection is also recommended through rubella vaccination, and a similar approach is taken to hepatitis B due to the potential for vertical transmission to infants and resulting organ damage.2 Management of chronic diseases such as diabetes and hypothyroidism is also considered important in pregnancy to reduce the effects on the developing fetus. Likewise, conditions managed with medication such as isotretinoids and anti-epileptic medication need to be approached with lower dosages or alternative medication as these drugs are teratogens and as such can cause birth defects.2
If a couple have been attempting to conceive for at least 12 months, then initial assessment of hormone levels, ovulation, weight/body composition and semen analysis is undertaken. In the longer term, gynaecological examination to check for physical factors interfering with conception (e.g. scarring from previous STI or endometriosis) is conducted.
Once the diagnosis of infertility has been made, the conventional treatment approach varies depending on the diagnosed reason for the infertility. If the diagnosis is male infertility, then the treatment will depend on the seminal analysis. If azoospermia (absence of sperm) is diagnosed, then conception relies upon donor insemination.6 However, if there is severe oligospermia (fewer than 5 million sperm), then a single spermatozoon is recovered from the epididymis and microinjected in the ovum. This has a 30% success rate.6 There have been some attempts to increase the sperm count of men with oligospermia using hormonal therapy (testosterone analogues and antioestrogens) with limited documented benefit.6 Another alternative in this situation is in vitro fertilisation.6
Alternatively, infertility may be due to female reproductive pathophysiology. Anovulation is managed by encouraging the woman to aim for an appropriate body composition, and use of an antioestrogen drug (clomifene), which has resulted in a 70% conception rate in amenorrhoeic women.6 If tubal damage has been diagnosed, there are really only two options available: microsurgery to attempt to repair the fallopian tubes, or in vitro fertilisation. With a diagnosis of cervical hostility, the traditional conventional approach is to encourage the couple to use condoms for 6 months in the hope that the antibodies attacking the sperm will be eliminated. Other, more invasive approaches include ingestion of oral corticoids by the male in the first 10 days of the woman’s cycle, the use of washed sperm, or in vitro fertilisation or gamete intrafallopian transfer techniques.6
RISK FACTORS
Cigarette smoking adversely affects fertility in both males and females.7–10 Smoking affects sperm production, motility, morphology and incidence of DNA damage in males;11 this may be explained by increased reactive oxygen species, which has been linked with lowered sperm concentration, motility and morphology.12 Cigarette smoking in females may affect the follicular microenvironment, and may cause alteration of hormone levels in the follicular phase.11 Both active and passive smoking have been demonstrated to increase zona pellucida thickness; this may make it more difficult for sperm to penetrate.13 In active smokers, the effect of delayed conception is increased with the number of cigarettes smoked.9 Despite these statistics, more than 10% of pregnant women continue to smoke cigarettes.14
Caffeine intake may also adversely affect fertility outcomes.15 Some research has found that coffee and/or tea intake greater than six cups a day is associated with reduced fertility.10 However, other researchers assert that coffee and tea consumption associated with reduced fertility rates in males and females is not dose related, and that constituents other than caffeine may also have an effect.8 Other drug use, such as recreational drugs and alcohol, may also contribute to certain subtypes of infertility.15
Another lifestyle factor that may affect fertility is diet and its associated nutritional status. A range of dietary constituents have been linked with various aspects of infertility including trans-fatty acids,16 iron,17,18 antioxidants,19,20 selenium21 and zinc.22 Increasing intake of vegetable protein and replacing animal protein may also reduce the ovulatory infertility risk.23 Similarly, a high glycaemic load diet and overall high dietary carbohydrates have also been associated with increased ovulatory infertility.24
Psychological stress is an added risk factor for reduced fertility in females25 and males.26 Depression in males has been correlated with decrease in sperm concentration and poor coping mechanisms have been associated with increased occurrence of early miscarriage.26
Both maternal and paternal age have a bearing on the fertility level of a couple. Older women experience more difficulty achieving and maintaining pregnancy, and are less likely to deliver a healthy infant than younger women.27 In females spontaneous cumulative pregnancy rates begin to decline as early as 31–35 years of age.27 One-third of women aged 35–39 years of age will experience difficulty achieving pregnancy, and half of women aged 40–44 years will have an impaired ability to reproduce.27 Increasing maternal age results in a decreased number of oocytes, decreased oocyte quality, uterine age-related changes affecting endometrial receptivity and neuroendocrine system ageing.27
Another general risk factor to consider when approaching preconception care is the presence of underlying disease. Women with a chronic disease such as diabetes have an increased risk of congenital abnormalities in their offspring, but are known to have improved birth outcomes when they plan their pregnancies and use preconception care.28 Coeliac disease is another condition which is known to incur higher miscarriage rates, increased fetal growth restriction and lower birth weights.29 Although not a disease, obesity may also affect fertility for both males30 and females.31 Sexually transmitted infections, particularly chlamydia and gonorrhoea, may lead to infertility.15 Infection of any nature may be associated with reduced sperm motility.32 Other conditions may affect fertility but, rather than the disease being detrimental, it is the medication used to manage the condition which is problematic. Several different types of medications, including hormones, antibiotics, antidepressants, pain-relieving agents, and aspirin and ibuprofen when taken in the middle of the cycle, have been reported to affect female fertility.4 With this in mind, it is important to address any underlying health issues, resolving them where possible, to reduce reliance on medication. Alternatively, where the condition cannot be resolved, exploration of substitute medication may be necessary.
KEY TREATMENT PROTOCOLS
A key naturopathic principle to be considered when supporting couples with fertility issues is to treat the whole person. It is vital that the approach to the development of a treatment plan for such couples is patient-centred, and does not make assumptions about their individual needs without diligent exploration of their health history and current health complaints. Such exploration must go beyond reproductive health, as a number of conditions not directly linked to the reproductive system have been associated with infertility. Examples of such conditions are inflammatory bowel disease,33 thyroid disease34 and type 1 diabetes.35 Other conditions more directly associated with the reproductive system which may need to be addressed include endometriosis36 and polycystic ovarian syndrome.37
Underlying conditions aside, preconception care will still benefit many couples by promoting health. Many lifestyle factors dramatically affect fertility, birth success and infant health.11 Preconception care must address these factors in order to promote fertility, conception and healthy pregnancy outcome. A study found that 81% of couples previously classified as infertile were able to conceive within 2 years of commencing an individualised preconception program.38
In general, due to the individual nature of preconception care, the treatment interventions used will vary significantly between couples; however, there are some remedies which are more commonly used. Common herbal medicines that may be useful when supporting couples during preconception care include Vitex agnus-castus and Tribulus terrestris. Vitex agnus-castus, or chaste berry, is used traditionally in fertility disorders, particularly for women with progesterone deficiency or luteal phase defects. No large studies have explored this role; however, a randomised, placebo-controlled trial (RCT) with 96 women with various fertility disorders (secondary amenorrhoea, luteal insufficiency and idiopathic insufficiency) taking Vitex agnus-castus for 3 months resulted in women with secondary amenorrhoea and luteal insufficiency achieving pregnancy twice as often as those in the placebo group.39 Previous smaller trials show similar results.40,41 Tribulus terrestris has also been associated with improving conception outcomes in women with endocrine sterility.42
Window of fertility
The first priority when approaching preconception care and couples with fertility issues is to establish the window of fertility. The window of fertility is probably best defined as the period in the 6 days leading up to ovulation, when in theory the oocytes and sperm should have maximum viability and survivability.43,44 However, in an individual clinical setting this can be more accurately garnered through analysis of intermenstrual intervals, cervical mucus and basal body temperature charts (see Chapter 20 on polycystic ovarian syndrome). Intercourse is most likely to result in pregnancy when it occurs within the 3 days prior to ovulation.
Although certainly not a prerequisite for pregnancy to occur, the probability of conception is highest when cervical mucus (vaginal secretions) is slippery and clear (see Figure 31.2).45–47 When combined with basal body temperature charts these simple and cheap analyses are able to predict peak fertility far better than menstrual charts alone. Cervical mucus analysis alone has been demonstrated to better predict peak fertility than either basal body temperature charts or biochemical ovulation detection kits based on LH.48
Monitoring cervical mucus may have other practical benefits as water-based vaginal lubricants can inhibit sperm motility by 60–100% in vitro.50 Mineral oil, canola oil or hydroxyethylcellulose-based lubricants do not seem to have this effect.
Diet
Dietary change is an important intervention in any preconception plan and, although the focus is on a general healthy diet for couples, some specific dietary choices have been found to have direct benefits for fertility. Replacing animal protein with vegetable protein, for example, has been found to be beneficial in women seeking to get pregnant.51 Similarly, low-fat dairy products have been connected with higher rates of anovulatory infertility, and higher dietary intake of trans-unsaturated fats have been linked with increased risk
of ovulatory infertility.52 Organic food may also be of benefit by reducing the potential exposure to environmental chemicals. Ultimately, the consensus seems to be that encouraging healthier eating habits more broadly improves fertility outcomes. As such, a healthy eating plan that includes foods with high levels of nutrients should be encouraged. High levels of brightly coloured fruit and vegetables to provide antioxidants plus good protein sources (meat if eaten, cheese, eggs, tofu if vegetarian; vegans need to be particularly careful with protein levels) and good-quality carbohydrates (wholemeal and wholegrain) should be routinely recommended (see Appendix 3, ‘Food sources of nutrients’).
Body composition
Overweight and obese women are less likely to conceive than those of normal weight.15 These women also experience increased risk of pregnancy complications and adverse pregnancy outcomes in comparison to women who weigh less. Conversely, women who are very underweight may also experience problems conceiving.15 Reproductive function can be affected by both obesity and low body weight, due to hormone imbalances and ovulatory dysfunction.11 Overall, the relative risk of ovulatory infertility is increased for body mass index (BMI) below 20.0 kg/m2 or above 24.0 kg/m2.53 There appears to be a 7% increase in the rate of fetal anomaly for each unit of BMI above 25.54 Obesity affects fertility in ways that are complex and not well understood; however, the association with functional hyperandrogenism and hyperinsulinaemia is thought to play an important role.55 Abdominal obesity in women with polycystic ovarian syndrome (PCOS) is considered to be co-responsible for the development of hyperandrogenism and chronic anovulation through mechanisms involving decreased concentrations of sex-hormone-binding globulin in the blood and insulin-mediated overstimulation of ovarian steroidogenesis.55 Obesity may also contribute to reduced outcomes of IVF/ICSI procedures by promoting resistance to clomiphene and gonadotrophin-induced ovulation.55 It has been demonstrated that weight loss in obese women can improve fertility through the recovery of spontaneous ovulation, and that others will have improved responses to ovarian stimulation in infertility treatment.56,57
Attenuating the hormonal imbalances resulting from high body fat can be achieved through both diet and exercise (as discussed in Chapter 20 on polycystic ovarian syndrome). Even after 12 weeks of dietary and exercise intervention, favourable menstrual and metabolic outcomes conducive to conception could be gained in infertile, overweight women.58 In fact, lifestyle modification proved more effective than fertility drugs in inducing ovulation in women with anovulatory disorders.59 However, it is important to note that weight loss needs to be approached responsibly, as rapid weight loss is understood to lower progesterone levels, slow follicular growth and inhibit the luteinising hormone surge, disallowing ovulation.60
Lifestyle activity
Maintaining an active lifestyle is beneficial in promoting both male and female fertility; however, moderation is very important. While moderate exercise may improve the chances of conceiving spontaneously or through fertility treatment,11 excessive physical exercise is associated with a spectrum of reproductive dysfunctions in both males and females. Female fertility issues associated with excessive exercise range from luteal-phase defects to anovulation to infertility and finally to amenorrhoea.53 Increase in vigorous activity (but not moderate activity) is associated with reduced relative risk of ovulatory infertility,53 and has been linked to poor IVF outcomes.61 This concern has also been found to affect male fertility, through subclinical changes in their reproductive hormone profile and semen parameters.62 For example, male endurance runners have been found to have a reduction in total and free testosterone, alterations in luteinising hormone release, and in pituitary responses to gonadotrophin-releasing hormone.62 Furthermore, there has been evidence of a change in the semen parameters of some endurance athletes, such as low normal sperm count, decreased motility and various morphological changes.62
This apparent contradiction between the benefits and risks of exercise can be best explained by the role of exercise in preventing and managing conditions that detrimentally effect fertility, such as polycystic ovarian syndrome and obesity.63 In contrast, any level of activity which induces metabolic stress will interfere with the hypothalamus–pituitary–gonadal axis, and therefore affect fertility.64 Overall, the focus when supporting couples prior to conception should be on moderate exercise that does not place undue stress on their systems.
Reduce risk factors
Factors such as smoking, caffeine intake and alcohol consumption may adversely affect fertility outcomes and should be reduced. Even if fertility is not yet a concern for a couple, these risk factors will still need to be addressed as they all have negative effects on the developing fetus and infant health. Maternal smoking during pregnancy, for example, has been linked to increased risk of wheezing in infants up to 2 years old65 and reduced fetal brain development,66 and may increase the infant’s risk of adult development of diabetes, hypertension and metabolic syndrome.67 Similarly, high alcohol consumption during pregnancy puts the developing fetus at risk of fetal alcohol syndrome.68 Even lower-level intake can affect the neuroendocrine and behavioural functions of the offspring.69
Stress
The emotional journey of a subfertile couple is complex. Seemingly innocuous events such as friends falling pregnant, family events and birthdays may trigger underlying anxiety issues (see Figure 31.3).
The process of undergoing infertility treatment itself can also be stressful and exacerbate anxiety, depression and stress, often enough to negatively affect pregnancy outcomes.72,73 This may be due to increased cortisol secretion, resulting from a normal stress response, down-regulating the hypothalamus–pituitary–gonadal (HPG) axis. It has been postulated that this may occur by inhibiting gonadotrophin-releasing hormone’s (GnRH) release of follicle-stimulating hormone (FSH) and luteinising hormone (LH) from the pituitary.74
As such, counselling or psychological support, particularly interventions which focus on stress management and coping-skills training, should be strongly recommended throughout this process.75 It is equally as important for the infertile couple to build a support network. Both attending support sessions and using cognitive behavioural interventions were equally effective in reducing the emotional aspects of infertility and improving the chances of pregnancy.76 Music therapy has also been associated with positive pregnancy outcomes.77 Overall, couples should be encouraged to take part in stress reduction activities at all stages of preconception and pregnancy. Anecdotal stories of previously infertile couples conceiving after ceasing trying or while on holiday are not to be ignored.78
Environmental concerns
Exposure to herbicides, fungicides, pesticides and other chlorinated hydrocarbons has been associated with decreased fertility and a higher risk of spontaneous miscarriage.79,80 Further to this, it should be noted that, although over 140,000 chemicals are in common use in today’s society, evaluation of the effects on reproduction of common physical and chemical agents has occurred in only 5% of substances.81 With this in mind, it is important to investigate potential exposure to environmental chemicals such as pesticides, herbicides, household chemicals, paint and paint thinners, and plastics. Paradoxically many couples will subject themselves to high levels of environmental toxins during ‘nesting’ activities while trying to conceive or during pregnancy. While preparation for the child is certainly important, activities that include exposure to dust, paint or other chemicals and substances that release toxins, such as home renovations, may adversely affect pregnancy outcomes and should be considered carefully.
If exposure is identified, and particularly if it is occupational (for example, factory workers, tradesmen, farmers and horticulturalists), then protective measures must be taken. Such measures include appropriate occupation health and safety interventions like wearing protective clothing and masks.82 Beyond this, the preconception treatment plan needs to incorporate suitable detoxification protocols (see the box on liver detoxification in Chapter 19 on endometriosis).
Immune dysfunction
Immune system imbalances may adversely affect fertility outcomes through a number of ways, including high generalised inflammation and antibodies targeted to key tissues. High levels of inflammatory prostaglandins, for example, may reduce uterine receptivity to fertilised embryos,83 possibly by affecting the regulation of genes necessary for human endometrial receptivity.84 Chronic inflammation may also contribute to the development of anatomic abnormalities such as pelvic adhesions and occluded fallopian tubes, as well as premature ovarian failure.85 Causes of inflammation in reproductive tissues vary and may include sexually transmitted infections such as Chlamydia trachomatis,
INFLAMMATION AND HEALTHY REPRODUCTION
Inflammation is often approached as an undesirable adversary in the human body. In fact, inflammation is a mechanism necessary for the normal and healthy reproductive process. As the luteinising hormone (LH) surge occurs prior to ovulation, LH stimulates granulosa cells to secrete inflammatory mediators (prostaglandins and cytokines) and progesterone. These compounds all trigger the secretion of matrix metalloproteinases, which break down the extracellular matrix, thereby allowing for follicular rupture and ovulation.85 As such, indiscriminate use of anti-inflammatory interventions in preconception care should be avoided.
endometriosis and autoimmune conditions.85 Autoimmune conditions which can contribute to infertility may be non-specific, such as type 1 diabetes mellitus and Hashimoto’s thyroiditis, or specific, such as antibodies that target FSH and LH and their receptors.86,87 Another such example is antibodies that target ovaries and sperm.84 It is worth noting, however, that the inflammatory response is also an important mechanism within healthy, normal reproductive function (see the box on inflammation and healthy reproduction). With this in mind, various measures to reduce inflammation systemically and specifically can be found in other relevant chapters.
Nutritional medicines
The primary conventional focus of nutrient supplementation in preconception care is on the role of folic acid in preventing neural tube defect.88 The benefits attributed to folic acid in the prevention of this condition require maternal sufficiency in the first 28 days of gestation, before many women know they are pregnant.88 It is this knowledge that has led to public health interventions such as folate fortification of bread flour and further supplementation of 400 μg/day for women of reproductive age.88
Folic acid is not the only nutrient required in preconception and the early stages of gestation. A recent longitudinal study89 observed the effect of pregnancy on the micronutrient status of the mothers. It was noted that, while folate levels decreased slightly during pregnancy and remained decreased up to 6 weeks after delivery, vitamin B12 progressively declined throughout gestation and reached marginal or deficient levels.89 This is of particular concern, as vitamin B12 has been overlooked as an important nutrient for preconception supplementation. Low maternal vitamin B12 status has been associated with a threefold risk of neural tube defect.90 This deviates from the previous approach to neural tube defect prevention, which has been firmly focused on folic acid supplementation and fortification of food. In fact, the focus on folic acid fortification of food, such as bread flour, may be contributing to a masking of vitamin B12 deficiency and an increased risk of neural tube defect91 (see the box on vitamin B12 and folate).
Various multivitamin and antioxidant nutritional supplements have improved pregnancy rates in those undergoing assisted reproduction92 or lowered time to conception in couples seeking preconception care.92,93 Preconception multivitamin use has also been associated with a higher incidence of multiple births for unknown reasons.94 Folate needs to be taken at least 3 months prior to conception for optimal benefit in reducing neural tube defects or leukaemia development in the fetus. However, it is also associated with decreased incidence of ovulatory infertility more generally.95 Vitamin C
VITAMIN B12 OR FOLIC ACID?
Folic acid has been used for a number of years to prevent neural tube defect;88 however, recent research has identified that vitamin B12 is also important in preventing this condition.90 With this in mind, the most predictable course of action may be to incorporate vitamin B12 supplementation into standard preconception care approaches alongside folic acid. Unfortunately, just as some concerns regarding the risks of folic acid supplementation masking vitamin B12 deficiency have been raised,91 excess vitamin B12 intake, resulting in potential cobalt toxicity,97 may also be a concern. To avoid this, and to stay true to the naturopathic patient-centred approach, assessing the most appropriate nutrients required for supplementation and the relevant dosages are vital. Folic acid is found predominantly in legumes and green leafy vegetables, while vitamin B12 is found in its most bioavailable form in animal products.98 As such, an assessment of a patient’s diet will provide an initial indication as to whether supplementation of folic acid and/or vitamin B12 is required. In general, though, it is important to remember that the absorption of vitamin B12 is an incredibly complex process that relies on healthy gastric, pancreatic and intestinal function, and that dysfunction in any one of these organs can compromise B12 status.98 A more thorough assessment of sufficiency of these nutrients can be gleaned through testing. The most accurate test to determine folic acid status is red blood cell folate, not the commonly used serum folate, which does not correlate with tissue stores.99 Vitamin B12 status can be assessed using serum cobalamin, which is more specific and stable compared with serum folate; however, both pregnancy and folate deficiency can result in false low readings. A more accurate assessment, which is independent of both of these conditions, is that of methylmalonic acid. Unfortunately, this test is much more expensive and technically demanding.100
supplementation has also had improved fertility outcomes in women with luteal phase defects.96
The male partner
It is important to realise that in 20% of infertile couples males are the sole cause of infertility and are an important contributing factor in a further 20–40% of infertile couples.101 Although many infertile men may have physical or structural conditions that require surgical intervention, many may have reversible issues that can be corrected with non-invasive measures. Men also experience declining fertility as they age—most profoundly after the age of 55 years but even men over the relatively young age of 35 years have half the chance of successfully inseminating as men under the age of 25 years.102
A decline in male fertility has been reported over the past few decades in a number of countries, though this has been controversial.103 It has been suggested that environmental and lifestyle factors such as increased occupational chemical and pesticide exposure are at least partly responsible for this decline.104–106 Oestrogen-like products are thought to be partly responsible. The fact that organic farmers have higher sperm counts than regular farmers or other exposed occupational groups lends further credence to this theory.107 Other environmental and lifestyle factors that may be affecting fertility include wearing tight-fitting clothing, using hot baths and spas and having occupations that require long periods of sitting down, as these behaviours all increase scrotal temperature.108 Dietary intake must also be considered, as it may affect semen quality. Men consuming diets high in meat and dairy products109 and soy protein110 have compromised semen parameters, whereas diets high in fruits and vegetables show benefit.109 The advantage in a fruit- and vegetable-rich diet may be attributed to an increased antioxidant intake.111
Beyond diet and lifestyle, some specific nutrients have been identified to improve fertility in men. For example, there is evidence that coenzyme Q10 supplementation can improve semen parameters in men,112,113 while vitamin C, vitamin E, beta carotene, folate and zinc are important for semen quality.4 A similar trial that identified increased pregnancy rates in couples with severe male infertility when taking an antioxidant supplement containing ascorbic acid, zinc, vitamin E, folate, lycopene, garlic oil and selenium has been conducted.114 In contrast, selenium has been demonstrated to improve sperm quality and motility in subfertile men, but not those diagnosed with infertility,115–117 or conversely with normal testicular selenium levels.118,119 Similarly, L-carnitine has been associated with increased semen quality and sperm concentration, particularly in groups with lower baseline levels,120–123 though one trial suggested that this may be true only in those with normal mitochondrial function.124
Assisted fertility procedures
Assisted reproductive technologies encompass a spectrum of methods and are valid options for infertile couples (see Table 31.2). However, the usefulness of these therapies needs to be considered by any prospective couple in the context of the costs and risks. For example, a systematic review of studies measuring the prevalence of birth defects in infants conceived using assisted reproductive technologies found a 30–40% increased risk.125 Furthermore, the average cost of IVF for Australian women is $32,903,126 while the success rate is 10% for a single IVF procedure, and increases to 40% if the procedure is repeated five times.6 Finally, the process of IVF requires constant emotional adjustment through each phase of the process,127 and can be debilitating for the woman in particular. To support this, a questionnaire study128 found that financial burden (23%), psychological stress (36%) and lack of success (23%) were the most predominant reasons couples discontinued IVF programs. In particular, a combination of lack of success and psychological stress was noted in 18% of participants.
| TYPE | PROCEDURE | PREGNANCY RATE∗ |
|---|---|---|
| Assisted insemination with husband’s sperm (AIH) | Sperm are transferred by catheter into uterus or fallopian tube. | Up to 15% per cycle |
| In vitro fertilisation (IVF) |
