EFFECTS ON THE MENSTRUAL-CYCLE OF IN-UTERO EXPOSURE TO DIETHYLSTILBESTROL

OBJECTIVES: The purpose of this study was to determine the effects of in utero exposure to diethylstilbestrol on the menstrual cycle. STUDY DESIGN: This was a prospective cohort study of 198 diethylstilbestrol-exposed women and 162 unexposed controls, recruited from women whose mothers participated in a randomized trial of diethylstilbestrol in pregnancy at the Chicago Lying-in Hospital from 1950 to 1952. Women with severe menstrual abnormality were excluded from the study. RESULTS: Diethylstilbestrol exposure was associated with a statistically significantly decreased duration of menstrual bleeding of approximately one half day and a lower average daily bleeding score (self-reported). We found no evidence for effects of diethylstilbestrol exposure on cycle length or variability of cycle length. Exposure was not related to symptoms of dysmenorrhea. CONCLUSIONS: The decreased duration and amount of menstrual bleeding among diethylstilbestrol-exposed women could be due to direct effects on the uterus. The lack of an effect on cycle length and variability appears to indicate that endocrine function is not grossly disturbed in those women studied.