CONTRACEPTIVES FOR LACTATING WOMEN - A COMPARATIVE TRIAL OF A PROGESTERONE-RELEASING VAGINAL RING AND THE COPPER T-380A IUD

From approximately one week before normal ovulation resumes, lactating women require protection against pregnancy by a contraceptive that is safe for both infant and mother. In a multicenter one-year study, the natural hormone, progesterone, delivered vaginally by a sequence of f our contraceptive rings designed for continuous use, was evaluated as a contraceptive for nursing mothers in comparison with the Copper T 38 0A IUD. individual rings release an effective average dose of 10 mg/da y for a 3-month period. Evaluation included measures of lactational pe rformance as well as of contraceptive efficacy and safety to mother an d child. Nine participating clinics enrolled 802 ring users and 734 IU D accepters between postpartum days 29 and 63. Life table analyses wer e performed with parallel decrements for ring and IUD subjects. Contin uation in the study and analysis required that subjects not stop breas tfeeding. The ring, with a one-year pregnancy rate of 1.5 per 100, did not differ significantly from the IUD with respect to contraceptive e ffectiveness (p > 0.05). More than half of the ring subjects were cont inuing at 6 months post admission and a quarter (23.5 per hundred) wer e still using the ring and breastfeeding one year after admission. Wom en with the IUD, however, had higher continuation rates (p < 0.001) at both time points. The largest single decrement for each method was th at for weaning. Ring users had more complaints of vaginal problems but had fewer vaginal disorders on examination. At 12 months postpartum, 46 per 100 continuing ring users remained in amenorrhea. Lactation per formance and the health and weight gain of the infants were similar am ong users of either regimen. (C) 1997 Elsevier Science Inc.