Uterine tonicity in proliferative and secretory phases of the menstrual cycle.

Hysterometry, a method for the quantitative evaluation of drug effect on the myometrium, has now been applied in a study of the changes in uterine tonicity during the menstrual cycle. Six nulli-gravidae women with regular menstrual periods and normal gynecological examination findings, were studied. Hysterometry was performed in the midproliferative, ovulatory, and midsecretory periods of the cycle and on the first day of menstruation. Uterine tonicity was found to be higher during the proliferative compared with the secretory phase. The change in uterine tonicity was correlated with a change in the quotient of concentration of estradiol and progesterone in serum (E2/P).