Incidence of ovulation in young women—a comment

Abstract

Comments on a recent article in which a much higher incidence of anovulatory menstrual cycles among women under age 25 than among older women was recorded, an observation that appeared to conflict with other data suggesting that women reach peak fertility between 20-25. The conclusion was that young women reach peak maximum fertility before their peak ovulatory efficiency. The author notes that the possibility that such an age distribution of anovulatory cycles could also be caused by a cohort effect was overlooked. The elevated incidence of anovulation could be due to an environmental change that affected recent cohorts more than earlier ones. Such effects have not been uncommon. Western populations in this century have experienced major epidemics of lung and breast cancer and cardiovascular disease, and postwar cohorts have also suffered apparent deterioration in semen parameters and a large increase in stilbestrol induced reproductive disorders. Cohort effects have been seen as real and important features of 20th century biology. Further studies are needed to determine the validity of the age distribution, and, if corroborated, several tests should be performed to distinguish between the 2 interpretations, including prospective studies and studies in less developed societies.