Estradiol and male fertility.

Serum estradiol (E2) levels were measured in 451 men attending an infertility clinic and 80 fertile men attending for vasectomy. The normal range of E2 levels found in fertile men was 70 to 200 pmol/l. Subfertile men had lower mean E2 levels than fertile men (P less than 0.05), but there was no relationship to obesity, cigarette smoking, age, or the male infertility diagnostic category. E2 levels in the subfertile group gave no prognostic information concerning future fertility. The authors conclude that E2 measurements in male patients are not useful in clinical infertility practice.

Duration of involuntary infertility and subsequent pregnancy.

During 1978-1983, 1,040 couples had been evaluated at our infertility clinic and subsequently followed up for an average of two years. The length of time the couple had been trying for a pregnancy (trying time) is shown to be strongly related to the subsequent chances of pregnancy. There are few effective treatments for male infertility and, therefore, these data may represent the spontaneous fertility rates from an untreated population. This background pregnancy rate should be useful to any physician planning a trial of treatment for the infertile couple when pregnancy is the success criterion, and allowance needs to be made for this spontaneous pregnancy rate when analyzing the results of treatments. Review of the literature suggests that some reported results could be misleading because of failure to allow for this background pregnancy rate.