SEXUAL-BEHAVIOR FREQUENCY AND MENSTRUAL-CYCLE LENGTH IN MATURE PREMENOPAUSAL WOMEN

(1) Women who had regular weekly sexual intercourse with men had menstrual cycles, the average duration of which was 29 days (range 26-33), while women with less frequent behavioral interactions tended to have more extreme cycle lengths, as shown in 3 different studies in which prospective double blind measurements of data were used. (2) The effect was noted consistently in college women but also occurred in infertile patients. Sexual behavior and consistent menstrual cycle length were associated in all women studied. (3) The mechanism appeared to be related to the regularity with which sexual activity occurred during all the non-menstruating days of the cycle. © 1979.