Preregistration study on the safety and contraceptive efficacy of a progesterone-releasing vaginal ring in Chilean nursing women

• Published in: Contraception (Stoneham) Vol. 60; no. 1; pp. 9 - 14
• Main Authors: Massai, Rebeca, Miranda, P, Valdés, P, Lavı́n, P, Zepeda, A, Casado, M.E, Silva, M.A, Fetis, G, Bravo, C, Chandı́a, O, Peralta, O, Croxatto, H.B, Dı́az, S
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.07.1999; Elsevier Science
• Subjects: Adult; Amenorrhea - chemically induced; Biological and medical sciences; Birth control; Birth Weight; Body Weight; Breast Feeding; breastfeeding; Chile; Colposcopy; contraception; Contraceptive Devices, Female - adverse effects; Contraceptive Devices, Female - standards; Copper-T IUD; Female; Gynecology. Andrology. Obstetrics; Hemoglobins - analysis; Humans; Infant; Intrauterine Devices, Copper - adverse effects; Intrauterine Devices, Copper - standards; Lactation; Male; Medical sciences; Milk, Human - drug effects; nursing women; Other methods of contraception. Sterilization; Parity; Patient Dropouts; Patient Satisfaction; Population; Progesterone - blood; Progesterone - pharmacokinetics; Progesterone - pharmacology; progesterone vaginal ring; Radioimmunoassay; Vagina - drug effects; Chile; Copper-T IUD; breastfeeding; nursing women; contraception; progesterone vaginal ring; Human; Lactation; Toxicity; Contraception; Breast feeding; Vaginal ring impregnated with active substance; Progestagen; Intrauterine contraceptive device; Female; Progesterone; Copper; Pharmacokinetics; Comparative study; South America; Americas; Progestational Hormones; Contraceptive Agents; Contraceptive Agents, Progestin; Biology; Hormones; Iud, Copper Releasing; Family Planning; Endocrine System; Vaginal Rings; Contraceptive Effectiveness; Latin America; Contraceptive Methods; Iud; Research Report; Developing Countries; Physiology; Chile; Contraceptive Agents, Female
• ISSN: 0010-7824; 1879-0518
• DOI: 10.1016/S0010-7824(99)00057-8

The contraceptive efficacy and safety of a progesterone-releasing vaginal ring (PVR) manufactured in Chile were compared to that of the Copper T 380A IUD (T-Cu) in nursing women enrolled at three Chilean clinics. A total of 285 volunteers chose to use the PVR and 262 the T-Cu. Plasma progesterone levels attained with the ring decreased from 25 to 14 nmol/L from month 1 to month 3 of use. Ring replacement was scheduled every 3 months. Volunteers continued in the study until weaning or completing the continuous use of four PVRs. No pregnancies occurred in 2320 and 2183 woman-months of exposure with the PVR and the T-Cu, respectively. Lower continuation rates in the first 6 months because of problems with use and a longer lactational amenorrhea were observed in the PVR than in the T-Cu group. Breast-feeding performance and infant growth were similar in both groups. These results confirm the high efficacy and safety of the PVR for nursing women and have led to the registration of the PVR by Chilean health authorities.