title: A multicenter comparative study on the efficacy, safety, and acceptability of the contraceptive subdermal implants Norplant and Norplant-II.
abstract: In order to assess efficacy, safety, and acceptability of the contraceptive subdermal implants Norplant and Norplant-II in Mexican women, a comparative phase III clinical trial was undertaken in eight clinics across the country. The study involved 1052 women who were followed-up trimonthly for three years. Cumulative pregnancy rates were 0.29% and 0.34% for Norplant and Norplant-II implants, respectively. Similar overall cumulative discontinuation rates were observed at three years: 50.38% for Norplant capsules, and 50.44% for Norplant-II rods. The main method-related reason for termination was endometrial bleeding irregularity which led to discontinuation rates of 11.94% and 11.62% for Norplant and Norplant-II contraceptive systems, respectively. In 15,279 woman-months of experience accumulated with Norplant implants and 14,092 with Norplant-II implants, there were few adverse events reported. No difference was found between the two groups in either difficulty for implants placement and removal or women's discomfort, even though the time required for insertion and removal of Norplant capsules was longer than for Norplant-II rods. It is concluded that during the first three years of use, both implants systems are equally effective, safe, and acceptable.
authors.affiliation: Department of Reproductive Biology, Instituto Nacional de la Nutrición Zubirán, México City, México.
authors.forename: M
authors.initials: M
authors.lastname: del Carmen Cravioto
authors.forename: G
authors.initials: G
authors.lastname: Alvarado
authors.forename: T
authors.initials: T
authors.lastname: Canto-de-Cetina
authors.forename: S
authors.initials: S
authors.lastname: Bassol
authors.forename: G
authors.initials: G
authors.lastname: Oropeza
authors.forename: R
authors.initials: R
authors.lastname: Santos-Yung
authors.forename: J
authors.initials: J
authors.lastname: Valencia
authors.forename: Y
authors.initials: Y
authors.lastname: Palma
authors.forename: J L
authors.initials: JL
authors.lastname: Fuziwara
authors.forename: T
authors.initials: T
authors.lastname: Navarrete
authors.forename: J
authors.initials: J
authors.lastname: Garza-Flores
authors.forename: G
authors.initials: G
authors.lastname: Pérez-Palacios
mesh_terms: D000328:Adult; D002214:Capsules; D015331:Cohort Studies; D003267:Contraception / Q000379:methods* / Q000592:standards / Q000706:statistics & numerical data; D003271:Contraceptive Agents, Female / Q000008:administration & dosage* / Q000009:adverse effects / Q000592:standards; D004343:Drug Implants; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016912:Levonorgestrel / Q000008:administration & dosage* / Q000009:adverse effects / Q000592:standards; D010352:Patient Dropouts / Q000706:statistics & numerical data; D017060:Patient Satisfaction / Q000706:statistics & numerical data; D018873:Pregnancy Rate; D012449:Safety; D013997:Time Factors
chemical_list: D002214:Capsules; D003271:Contraceptive Agents, Female; D004343:Drug Implants; D016912:Levonorgestrel