Sexual behavior and steroid levels among gynecologically mature premenopausal women.

Twenty-seven gynecologically mature young women who participated in a 14-week study prospectively recorded daily sexual behavior and basal body temperature data. In addition, they supplied plasma three times during the last cycle of participation. Plasma was analyzed for estradiol (E2), testosterone (T), and progesterone (P) by radioimmunoassay. The levels of circulating sex steroid hormones during the luteal phase were examined in relation to measures of menstrual cycle length, sexual frequency, and coital total. The results indicated the following: (1) women who had weekly sex with men had higher levels of estrogen than women who did not; (2) total amount of coital behavior was not related to any of the hormones assayed; (3) neither T nor P were distinguished by the consistency of sexual behavior or by coital total; and (4) women with aberrant-length cycles tended to have lower levels of E2. Thus, E2 consistently showed relationships to sexual behavior and cycle length, whereas P and T did not.