Chapter Seven. Infertility
Introduction
Considering the size of the world’s population, the fertility of humans is quite low compared with other mammals. Fertility in Western couples has steadily decreased since 2001 and was estimated at 1.84 children per woman (Office of National Statistics 2008). After the widely publicised birth of Louise Brown, the first ‘test-tube’ baby, in 1978, couples could be helped to conceive and sought advice. Midwives will come into contact with families who have had a problem in conceiving and will need to understand infertility, its treatment and its consequent effect on the family and parenting (Allan & Finnerty 2007, Sidebotham 2001).
Defining infertility
NICE Guidelines (NICE 2004) define infertility as ‘failure to conceive after regular unprotected intercourse for 2 years in the absence of known reproductive pathology’. For couples who do not conceive, the desire to have a baby may be all-consuming. The couple may blame each other and this could cause marital/partnership disharmony; to seek help, the couple must recognise that a problem exists and a third party has to be brought into their intimate lives. Motherhood brings social status; referral to infertility clinics permits women to verbalise their worries with other women in the same circumstances, whereas contact with fertile women often brings conflict and emotional pressure (Allan 2007). The male suffers too if he is positively diagnosed as subfertile and somehow he feels he has not proved himself as ‘manly’ (Bainbridge 2007a).
Infertility affects as many as 1 in 6 couples; 80% can be helped by assisted reproductive technology (ART) using their own gametes, and a further 10–15% can be helped by the use of donated gametes (Fishel et al 2000). The Human Fertilisation and Embryology Authority (HFEA) (2008) state that 1.4% of all births in the UK result from infertility treatment. Many couples are delaying their first pregnancy and fertility declines after the age of 30 in both women and men (Balen & Rutherford 2007a, Brosens et al 2004). The age at first birth has risen from 28.6 years in 2001 to 29.2 years in 2006 (Office of National Statistics 2008).
The causes of male and female infertility
The causes of infertility listed in Table 7.1 indicate that investigations should ensure that:
1. Adequate numbers of sperm are deposited around the cervix (postcoital test).
2. The endometrium is in an appropriate state to receive the fertilised ovum (endometrial biopsy).
3. The fallopian tubes are patent (laparoscopy, salpingography).
4. Ovulation occurs (endometrial biopsy, hormonal assays).
5. The woman is psychologically prepared for pregnancy.
| Male | Female |
|---|---|
| Defective spermatogenesis | Defective ovulation |
| Endocrine disorders: dysfunction of the hypothalamus, pituitary, adrenal glands or thyroid gland | Endocrine disorders: dysfunction of hypothalamus, pituitary, adrenal glands or thyroid gland |
| Systemic disease such as diabetes mellitus | Systemic disease such as renal disease |
| Testicular disorders: trauma or environmental | Ovarian disorders: hormonal or polycystic ovarian syndrome or endometriosis |
| efective sperm transport | Defective transport |
| Obstruction or absence of seminal ducts | Ovum: because of tubal obstruction or fimbrial adhesions |
| Impaired secretions from accessory glands | Sperm: because of thick cervical mucus or loss of tubal patency |
| Ineffective sperm delivery | Defective implantation |
| Impotence due to psychosexual problems | Due to hormone imbalance, congenital anomalies, fibroids or infection |
| Drug-induced problems by either prescription or recreational drugs | |
| Physical anomalies |
Table 7.2 indicates the causes of subfertility, expressed as a percentage (Johnson 2007).
| Cause | Approx. percentage frequency |
|---|---|
| Endometriosis | 12 |
| Tubal damage | 14 |
| Ovulatory problems | 22 |
| Sperm defects | 24 |
| Unexplained | 28 |
Investigations for infertility
The general health of both partners should be investigated; a body mass index of 19–29 would be ideal; smoking cessation, prescription and recreational drug use and the amount of alcohol consumed each week are other factors (NICE 2004). Hypertensive men treated with calcium channel blockers have poor sperm motility, and insulin-dependent diabetes has been shown to be detrimental to reproduction in the male (Agbaje et al 2007, Balen & Rutherford 2007b).
Frequency and behavioural aspects of coitus and any reproductive history of both partners should be discussed (NICE 2004). Regular spontaneous intercourse is preferable to calculated fertile times and enforced unnatural coupling and its consequent effects on both partners, but this will inevitably change once infertility is diagnosed (Brosens et al 2004).
Male infertility
One in 20 men will be affected by subfertility, mainly caused by dysfunctional spermatozoa thus reducing their fertilising capacity. Environmental factors such as oestrogenic compounds in the drinking water may in part be to blame for lower sperm counts and the increase in cryptorchidism and testicular cancer (Hirsh 2003).
Semen analysis and sperm deposition
Specimens of semen are obtained into a clean dry glass jar by coitus interruptus or by masturbation following 2 days of abstinence from coitus and examined in the laboratory within 1 h of collection. The alternative to this is a postcoital test, which also assesses the reaction of the sperm on the cervical mucus and could give an indication of the sperm’s ability to fertilise the ovum. Semen analysis is more accurate when performed on its own, and ideally an average of three specimens at 2–3-week intervals allows calculation of a semen value.
Normal values for semen (WHO 2002):
• Volume >2 ml.
• Sperm concentration 20 million/ml.
• Motility >50% progressive or >25% rapidly progressing.
• Morphology >15% normal forms.
• Viscosity after liquefaction low.
• White blood cells <1 million/ml.
• Antibodies coating sperm <10%.
Postcoital test
A specimen of cervical mucus taken at the fertile part of the woman’s cycle and within 6 h of intercourse is examined. This test can be used to ascertain the following:
• The quality of the cervical mucus.
• The sperm’s ability to penetrate the cervical mucus.
• The effectiveness of intercourse.
• The presence of immunological problems.
Defective spermatogenesis
Absence of sperm (azoospermia) is uncommon. It may be due to defective spermatogenesis or damage to the transport ducts. Levels of follicular stimulating hormone and testicular size determine diagnosis. Modern ART can help 75% of these men (Hirsh 2003). Defective spermatogenesis may follow abnormal development of the testes due to poor development of the Sertoli cells. This may be genetic in origin. Late or non-descent of the testes may also have a genetic background and is now treated early in the baby’s first year of life by surgery.
Biopsy of the testes and epididymis will show whether sperm are being produced. Two techniques are available: microsurgical epididymal sperm aspiration (MESA) and extraction of individual sperm cells from testicular tissue or testicular sperm extraction (TESA). Chromosomal studies will indicate whether the problem is a chromosomal translocation, which affects the meiotic division of spermatozoa causing aneuploidy in the offspring. While it is possible to assist couples with a genetic disorder, preimplantation chromosomal analysis of the conceptus is necessary to prevent abnormal fetuses being implanted (Ferlin et al 2006, Flinter 2001).
Infection, such as mumps with its complication of orchiditis, may damage the male tubular system. Chlamydia trachomatis infection is often asymptomatic and is associated with unexplained male infertility, and certain uropathogenic organisms have been found to affect sperm motility when bacterial counts are high. Treatment with antibiotics and vitamins C and E improves pregnancy rates (Hirsh 2003). Varicoceles, varicose veins of the scrotum, may cause raised testicular temperature and affect the size of the testes, but it is debatable if they are the cause of or are just associated with subfertility (Redmon et al 2002). Sperm production may be improved by eating healthily and by reducing alcohol intake and smoking.
Blood tests for hormone levels sometimes indicate possibilities for treatment. Reduced follicle-stimulating hormone (FSH) may respond to clomifene, while high levels of prolactin may respond to bromocriptine. Treatment with testosterone does not appear to stimulate sperm production. Some authorities recommend that fructose, zinc and acid phosphatase levels in seminal fluid should be measured when the sperm count is reduced. Low levels of fructose and zinc or high levels of acid phosphatase suggest a low-grade vesiculoprostatitis. Antibiotic treatment of prostatic infection may improve sperm count and motility.
Sexual dysfunction
Other causes of infertility include impotence and retrograde ejaculation into the bladder. Some men may benefit from medication such as sildenafil (Viagra) (Hirsh 2003). Artificial insemination by the husband’s semen (AIH) may be useful in these cases or intracytoplasmic sperm injection (ICSI) (see below). Intrauterine insemination (IUI) transcervically with prepared partner’s sperm with or without ovarian stimulation is also commonly used at the fertile time, 35–38 h prior to luteinising hormone surge (Bensdorp et al 2008).
