The Length of the First Three Menstrual Cycles After Combined Oral Contraceptive Treatment

This report describes the time-interval between the last withdrawal bleeding and the first 2 or 3 spontaneous menstrual periods in 516 women who had used combined oral contraceptives for periods of 9 to 55 months. The first 300 patients applying for renewal of their prescriptions for oral contraceptives were recommended to withold the medication until they had had 2 spontaneous menstrual periods. Later 216 women were asked to wait for 3 spontaneous menstrual periods. Although several combined oral contraceptives had been used 77.5% had taken Conluten which is norethindron 2 mg and mestranol .1 mg. In 1 group patient menstrual cycles had been regular and of about 1 month duration before taking the contraceptive. In a second group periods had been irregular. In a third group periods had been regular but of unusually short or long duration. During the observation time 17 pregnancies occurred. In most of those who had usually had regular periods the first menstrual cycle after stopping therapy was about 6 days longer than the following ones which were the same as before therapy. Of the 515 subjects 4 developed amenorrhea lasting more than 180 days. Of these 3 had had irregular menstrual periods before using contraceptives. It is therefore recommended that combined oral contraceptives be used with caution in women who have irregular menstruation especially in those who have not completed their family.