Dehydroepiandrosterone sulfate and anovulation increase serum inhibin and affect follicular function during administration of gonadotropins

To test the hypothesis that testosterone (T) derived from circulating dehydroepiandrosterone sulfate (DS) or produced in excess within the anovulatory ovary is a follicular regulator capable of stimulating inhibin secretion, DS and inhibin were determined by RIA in residual serum samples from in vitro fertilization cycles and analyzed along with other parameters using analysis of variance and stepwise multiple linear regression after log transformation of the RIA data. It was predicted that the serum concentration of inhibin would be higher in women with anovulation than in normal subjects and that the serum inhibin concentration would have a positive regression coefficient on the serum DS concentration. The serum concentrations of inhibin (P < 0.01) and estradiol (P < 0.001) on the day of hCG treatment were higher in women with anovulation than in normal subjects, as was the number of oocytes retrieved (P < 0.001). The FSH and LH doses (both P < 0.005) and age (P < 0.001) were significantly lower, and the average duration of gonadotropin therapy was 1 day shorter (P < 0.001) in anovulatory patients. There was no significant difference in serum DS (P > 0.2). Regression analysis showed that serum inhibin was positively related to the number of oocytes (P < 0.001) and serum DS (P = 0.05), with an increase in anovulatory subjects (P < 0.025). The duration of treatment with gonadotropins was related positively to the patient's age (P < 0.001) and negatively to serum DS (P < 0.025), with a decrease in anovulatory subjects (P < 0.025). The number of oocytes obtained was negatively related to age (P < 0.001) and positively to serum DS (P < 0.005). These data are consistent with a stimulatory effect of follicular T derived from either circulating DS or the anovulatory ovary, which affects the secretion of inhibin, the duration of gonadotropin treatment, and the number of oocytes retrieved.