ORIGINAL ARTICLE Reproductive epidemiology The influence of sporadic anovulation on hormone levels in ovulatory cycles

study question: Do ovulatory hormone profiles among healthy premenopausal women differ between women with and without sporadic anovulation? summary answer: Women with one anovulatory cycle tended to have lower estradiol, progesterone and LH peak levels during their ovulatory cycle. what is known already: Anovulation occurs sporadically in healthy premenopausal women, but the influence of hormones in a preceding cycle and the impact on a subsequent cycle’s hormone levels is unknown. study design, size, duration: The BioCycle Study was a prospective cohort including 250 healthy regularly menstruating women, 18–44 years of age, from Western New York with no history of menstrual or ovulation disorders. The women were followed with up to eight study visits per cycle for two cycles, most of which were consecutive. participants/materials, setting and methods: All study visits were timed to menstrual cycle phase using fertilit