Use of a single implant of elcometrine (ST-1435), a nonorally active progestin, as a long acting contraceptive for postpartum nursing women

Abstract

Because of its unique features, the contraceptive effectiveness and tolerance during breast-feeding of 16-methylene-17 alpha-acetoxy-19-nor-4-pregnene-3,20-dione (elcometrine), delivered within a single subdermal capsule of medical grade polydimethylsiloxane, was investigated. Unlike other progestational steroids, elcometrine has no affinity for androgen and estrogen receptors and is inactive by the oral route. A total of 66 breast-feeding women receiving elcometrine by the subdermal route were enrolled in the study, and 69 women who elected to use Copper-T380 intrauterine devices (IUD) served as control subjects. The women and their infants were observed until the end of the first postpartum year. There were no significant differences in growth and development measurements among the infants in the elcometrine and control groups. The percentage of infants continuing to breast-feed at 3 and 6 months was significantly higher in the elcometrine group. There were no significant differences between the concentration of elcometrine in the mother's blood and milk. At 75 days, blood levels of elcometrine in the infants were near the undetectable and were significantly lower than the levels in maternal blood or milk (p < 0.01). In 15 of 25 infants, blood levels of elcometrine were at the limit of assay sensitivity or undetectable. Two pregnancies occurred in women using IUD, whereas none occurred in those using implants. There were menstrual bleeding irregularities in both groups. A single elcometrine capsule placed subcutaneously at 6-monthly intervals appears to be an effective method of contraception for lactating women and results in blood concentrations of nursing infants at or near undetectable levels.

PIP: Discusses the effects of the use of a single implant of elcometrine (ST-1435), a nonorally active progestin, as a long acting contraceptive for postpartum nursing women in Maternidade Climerio de Oliveira in Salvador, Bahia, Brazil. A total of 135 women aged 18-35 years having a singleton term delivery, fully breast-feeding on demand, planning to breast-feed for 6 months postpartum, and requesting effective contraception were recruited. The method was initiated for 6 weeks postpartum. Results showed that 66 breast-feeding women used elcometrine implants, while 69 women preferred an IUD insertion. The contraceptive efficacy of lactation is high for women breast-feeding on demand, particularly in those who remain in amenorrhea during the 6 months postpartum; in these women, elcometrine implant and IUD prevented pregnancy effectively. Breast-feeding was significantly higher (p 0.05) in the elcometrine group at 3 and 6 months, while at 9 and 12 months there was no statistical difference. The differences in type, frequency of supplementary feeding, and anthropometric measures between the two contraceptive groups were not significant. Menstrual irregularities were present in both groups. Thus, elcometrine could be best alternative and the most effective method of contraception for lactating women.