Ovulation suppression in women following vaginal administration of oral contraceptive tablets

Abstract

A preliminary trial was conducted to test the possibility of using intravaginally a contraceptive tablet manufactured for oral use to achieve ovulation suppression. 12 women who could not continue with oral contraceptives (OCs) because of gastrointestinal complaints and/or nausea volunteered to participate. All subjects discontinued oral use of tablets for at least 2 months prior to the vaginal administration. Condoms were provided for use during the interim period. Patients were instructed to manually place in the vagina either 1 (4 subjects) or 2 tablets (8 subjects) daily for 21 days. Progesterone blood levels remained at preovulatory levels, below 2 ng/ml, throughout the treatment period, indicating that ovulation was suppressed in all subjects. Levels of 17beta-estradiol (32) which showed considerable variation during the control cycle remained low during the treatment cycle. Withdrawal bleeding occurred 2-5 days following the last tablet and lasted 3-5 days, as in normal menstruation. In patients inserting 1 tablet, intermenstrual spotting was common, but in those inserting 2 tablets daily no spotting occurred. 5 of 6 subjects who complained of nausea during OC use reported no nausea during the period of vaginal administration. These patients requested vaginal administration as a regular contraceptive method.