NORPLANTTM (Laboratorios Gutfol, S.A., Mexico City, Mexico) subdermal implants containing levonorgestrel were accepted by 816 women in a two-phase study initiated in 1975 and augmented in 1978. Through 3 years of first-segment use, acceptors experienced five pregnancies, a cumulative net rate of 0.7 per 100, and a gross pregnancy rate of 1.1 per 100. First-segment continuation at 3 years was at
... [Show full abstract] the rate of 44.6 per 100, an annual average of 76 per 100. NORPLANT users experienced irregular menstruation, with high interindividual variation, but with normal average numbers of bleeding days and of bleeding episodes. Hemoglobin levels increased moderately during implant use. The incidence of systolic blood pressure readings above 145 mm Hg or diastolic readings above 95 mm Hg was similar to that observed among users of the TCu 200 intrauterine device enrolled under the same selection criteria in the same clinics between the two phases of the NORPLANT study. Comparative data on pregnancy and other rates are also given for these intrauterine device acceptors.
