Failure to conceive for the first time after one year of regular timed sexual intercourse without contraception or after 6 months trying for a second or subsequent pregnancy

Biochemical investigations for the infertile female

  • take blood on day 21 for progesterone (or 7 days before the next period)
  • other investigations should be performed on days 1-5 as FSH is then predictive of pregnancy outcome
Progesterone (see gynaecological endocrinology for interpretation)
Rubella status check if not known
LH & FSH not necessary
Prolactin only if cycles irregular or if there is galactorrhoea
Thyroid tests only if cycles irregular or other clinical indication

Investigation for the infertile male

Males should initially be investigated with semen analysis. Repeatedly low counts suggest testicular insufficiency.

Primary testicular failure may be due to trauma, infections etc and would be suggested by low testosterone and  raised gonadotropins.

Secondary testicular failure is due to pituitary disease and would be suggested by low testosterone and low gonadotropins.

Some men with erectile dysfunction have raised FSH. The cause and explanation for this is unknown.

Page updated: 20/04/10 | Updated by: Dr. Julian Barth