Effect of an oral contraceptive on uterine tonicity in women with primary dysmenorrhea

Abstract

Hysterometry, a method for quantitative evaluation of the effect of pharmacologically active agents on the myometrium, has been applied to determine the effect of an oral contraceptive on uterine tonicity. Hysterometry was performed on the first day of each of two consecutive menstrual periods in 5 dysmenorrheic women. During the second cycle the women were given ethinylestradiol 50 microgram and lynestrenol 1 mg per day for 22 days. After the intake of this oral contraceptive, uterine tonicity decreased in all women, the decrease being accompanied by relief of dysmenorrheic pain.

PIP: The study objective was to determine uterine tonicity quantitatively by hysterometry--a method for quantitative evaluation of the effect of pharmacologically active agents on the myometrium--during menstruation in dysmenorrheic women, with special regard to the effect of an oral contraceptive (OC). 5 volunteers with severe primary dysmenorrhea were studied. The age range of these nulligravida was 17-25 years. All had normal menstrual periods and normal findings on gynecological examination. Hysterometry was performed on the 1st day of each of 2 consecutive menstrual periods, the 1st occurring after a non-medicated cycle and the 2nd after the use of an OC, ethinylestradiol 50 mc + lynestrenol 1 mg. Medication was started on the 5th day of the menstruation period and lasted 22 days. The women were instructed to register any side effects of the medication as well as the effect on the menstrual pain. All the women had severe menstrual pain before the treatment with OC. After the treatment daily for 22 days, 2 women had no pain at all and 3 only mild pain during the 1st day of the menstruation. Hysterometry on the 1st day of dysmenorrheic menstruation resulted in tonicity values (intercepts) between 110 and 217, mean 158. Hysterometry on the 1st day of bleeding after treatment with the OC resulted in tonicity values between 91 and 167, mean 117. There was almost a significant differences between the untreated and treated situations. The women who had the most marked decrease in uterine tonicity had no menstrual pain after the treatment; women who had the least decrease had mild menstrual pain during the 1st day of menstruation.