Infertility/Subfertility

INTRODUCTION

Subfertility is defined as the absence of conception after a period of 12 months of normal unprotected sexual intercourse.

Key facts and checkpoints

• Subfertility affects 10–15% of all cohabiting couples

• The main factors to be assessed are ovulation, tubal patency and semen analysis

• Approx. 40–50% of couples have an identifiable male factor

• Female factors account for ~45%: tubal problems account for ~20% and ovulatory disorders ~20%

• Polycystic ovary syndrome is the most common cause of ovulatory dysfunction ( 404–5); consider endometriosis

• Approx. 20% of cases have no apparent explanation

• A significant number (25%) have combined male and female problems

• Current specialised treatment helps 60% of subfertile couples to achieve pregnancy; refer within 1 year if ≤35 y, 6 months if >35 y

A DIAGNOSTIC APPROACH

It is important to see both partners, not just the woman.

History A careful history should include sexual function such as adequate intercourse, past history (esp. STI or PID), occupational history, drug intake and menstrual history.

Physical examination A general assessment of body habitus genitalia (incl. vaginal and pelvic examination), general health incl. diabetes mellitus, and secondary sexual characteristics should be noted in both man and woman. Urinalysis should be performed on both partners.

Note: Testicular size (measured with orchidometer)

• normal size 15–35 mL (average 18 mL)

• small testes 15 mL; Klinefelter 7–8 mL

First-line investigations

• Serum LH, FSH and oestradiol in

• Serum progesterone (mid-luteal/day 21) can be used to confirm ovulation, although a regular 26–34 d cycle usually suggests ovulation

• Semen analysis

• Transvaginal ultrasound (day 5–9 of cycle) for ‘antral follicle count’

• Androgens (free testosterone, SHBG, FAI, 17-OH progesterone), TFTs and serum prolactin

• Anti-Müllerian hormone (AMH): interpretation may be complicated and require specialist input

Male—semen analysis:

Collection should be made directly into a sterile container 2–3 days after sexual abstinence. Semen should be kept at body temperature and examined within 1 hour of collection.

Normal values:

• volume ≥1.5 mL (av. 2–6)

• concentration ≥15 million sperm/mL

• total sperm count ≥39 million

• progressive motility ≥32%

• normal forms ≥4%

• vitality ≥58%

• normal forms ≥4%

Female—further investigations:

• routine preconception screening

• thyroid antibodies

• chlamydia (first-pass urine NAAT) if indicated

• consider genetic testing for fragile X gene mutation, cystic fibrosis and spinal muscular atrophy

REFERRAL

Recommended after planned conception for 1 yr if the woman is ≤35 yrs, 6 months if >35 yrs. Consider early referral for women with amenorrhoea or oligomenorrhoea, or couples with a known reason for infertility.