Delayed first injection of a once-a-month injectable contraceptive containing 25 mg of medroxyprogesterone acetate and 5 mg of E-2-cypionate: effectson ovarian function

Objective: To assess whether women who were administered the first injectio n of DMPAcE+E2C on day 7 of their menstural cycle (delayed injection) exhib it the same degree of ovarian suppression as women who receive it on day 5 of their menstrual cycle. Design: Multicenter, randomized controlled trial. Setting: Reproductive health clinics. Patient(s): Women aged between 18 and 38 years (inclusive) willing to use D MPA+E2C as their method of a contraception. Intervention(s): Participants received a DMPA+E2C injection an day 5 (contr ol group, n = 41) or day 7 (delayed-injection group, n = 117) of their mens trual cycle. Main Outcome Measure(s): Ovarian activity and follicular development determ ined by serial serum progesterone levels and vaginal ultrasound. Result(s): Participants who received DMPA+E2C on day 5 of their menstrual c ycle (control group) exhibited no more than limited follicular growth (no f ollicle > 16 mm). Of those women who received DMPA+E2C on day 7 of their me nstrual cycle (delayed-injection group), 21 (18%) showed some follicular gr owth, of whom 4 (3%) ovulated. Conclusion(s): The first injection of DMPA+E2C given on day 7 of a menstrua l cycle does not provide the same inhibition of ovarian activity as that ob served when it is administered on day 5 of the menstrual cycle. (Fertil Ste ril (R) 2001;75:744-8 (C) 2001 by American Society for Reproductive Medicin e.).