NORPLANT and NORPLANT-2 implant contraceptives were associated with an overall cumulative five-year pregnancy rate of 3.5 per 100, with rates below 1 per 100 in women weighing less than 50 kg.
Do NORPLANT and NORPLANT-2 implant contraceptives provide effective long-term pregnancy prevention?
NORPLANT implant contraceptives provide highly effective long-term contraception over five years, with efficacy being particularly high in women weighing less than 50 kg.
Experience encompassing more than 20,000 woman-years of use of NORPLANT capsules and 6,000 woman-years of trials of NORPLANT-2 rods is reviewed. Implant contraception repeatedly has been associated with low pregnancy rates and high continuation rates through five full years of use. Weight has proved to be a factor related to effectiveness. Women weighing less than 50 kg experienced cumulative five-year pregnancy rates well below 1 per 100, whereas the overall cumulative rate has been 3.5 per 100. Medical events reported during use that have led to discontinuation are analyzed from four large data sets.
Irving Sivin (1988) conducted a review in Contraception. NORPLANT and NORPLANT-2 Contraceptives was evaluated on Cumulative five-year pregnancy rate. NORPLANT and NORPLANT-2 implant contraceptives were associated with an overall cumulative five-year pregnancy rate of 3.5 per 100, with rates below 1 per 100 in women weighing less than 50 kg.