A/oligomenorrhoea & infertility
When couples present with infertility both partners require evaluation. If semen analysis is abnormal an endocrine profile, including testosterone and gonadotropins will be required from the male partner.
Women with regular periods are unlikely to have an endocrine problem. A luteal phase progesterone is probably not necessary (see below). Rarely hyperprolactinaemia may cause anovulation in women with regular cycles, but far more often there is associated menstrual disturbance.
Polycystic ovary syndrome is a clinical diagnosis, women presenting with any of acne, hirsutism, oligomenorrhoea or subfertility. Transvaginal ultrasound, particularly when performed by an experienced operator, may corroborate the clinical impression.
Since women with regular cycles (30+/-2 days) ovulate in 95% of those cycles, progesterone measurement is probably unnecessary. Blood samples for progesterone need to be taken at the mid luteal point which is 7 days prior to the onset of the next menstrual bleed. Therefore in women who are cycling regularly, the commonest cause of a low progesterone (10-30 nmol/L) is likely to be due to inaccurate sample timing.
High concentrations of progesterone ie > 100nmol/L may indicate early pregnancy.
FSH for prediction of fertility
Measurement of FSH on day 3 can give some guide to the odds for successful conception. If the FSH > 8 IU/L there is a reduced chance of conception which becomes slim when FSH > 15 IU/L.
Monitoring women with erratic cycles
In women with erratic cycles, it may be more appropriate to co-ordinate endocrine tests with ultrasound monitoring of ovarian activity.
- Hull MGR, Savage PE, Bromham DR, Ismail AAA, Morris FA. The value of a single serum progesterone measurement in the midluteal phase as a criterion of a potentially fertile cycle ("ovulation") derived from treated and untreated conception cycles. Fertil Steril 1982;37:355-360.
- Kyei-Mensah AA, Jacobs HS. The investigation of female infertility. Clin Endocrinol (Oxf) 1995;43:251-255.