title: Preregistration study on the safety and contraceptive efficacy of a progesterone-releasing vaginal ring in Chilean nursing women.
abstract: 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.
authors.affiliation: Instituto Chileno de Medicina Reproductiva, Consultorio de Planificación Familiar, Santiago, Chile.
authors.forename: R
authors.initials: R
authors.lastname: Massai
authors.forename: P
authors.initials: P
authors.lastname: Miranda
authors.forename: P
authors.initials: P
authors.lastname: Valdés
authors.forename: P
authors.initials: P
authors.lastname: Lavín
authors.forename: A
authors.initials: A
authors.lastname: Zepeda
authors.forename: M E
authors.initials: ME
authors.lastname: Casado
authors.forename: M A
authors.initials: MA
authors.lastname: Silva
authors.forename: G
authors.initials: G
authors.lastname: Fetis
authors.forename: C
authors.initials: C
authors.lastname: Bravo
authors.forename: O
authors.initials: O
authors.lastname: Chandía
authors.forename: O
authors.initials: O
authors.lastname: Peralta
authors.forename: H B
authors.initials: HB
authors.lastname: Croxatto
authors.forename: S
authors.initials: S
authors.lastname: Díaz
mesh_terms: D000328:Adult; D000568:Amenorrhea / Q000139:chemically induced; D001724:Birth Weight; D001835:Body Weight; D001942:Breast Feeding; D002677:Chile; D003127:Colposcopy; D003274:Contraceptive Devices, Female / Q000009:adverse effects / Q000592:standards*; D005260:Female; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D007223:Infant; D007435:Intrauterine Devices, Copper / Q000009:adverse effects / Q000592:standards; D007774:Lactation; D008297:Male; D008895:Milk, Human / Q000187:drug effects*; D010298:Parity; D010352:Patient Dropouts; D017060:Patient Satisfaction; D011374:Progesterone / Q000097:blood / Q000493:pharmacokinetics* / Q000494:pharmacology; D011863:Radioimmunoassay; D014621:Vagina / Q000187:drug effects
chemical_list: D006454:Hemoglobins; D011374:Progesterone