Contraceptive efficacy and clinical performance of Nestorone implants in postpartum women.

The objective of this study was to evaluate the contraceptive efficacy and clinical performance of a Nestorone subdermal implant (NES) in the postpartum period. NES (n = 100) and Copper T intrauterine device (T-Cu; n = 100) acceptors initiated contraception at 8 weeks postpartum and were followed at monthly intervals during the first year and at 3-month intervals thereafter. Pregnancy rates, breastfeeding performance, infant growth, bleeding pattern, and side effects were assessed. Blood and milk NES concentration were measured. No pregnancy occurred in 2195 and 2145 woman-months of NES implant and T-Cu use, respectively. No effect of NES on lactation and infant growth and no serious adverse events were observed. Lactational amenorrhea was significantly longer in NES users (353 +/- 20 days) than in T-Cu users (201 +/- 11 days). More NES users (55.8%) experienced prolonged bleedings than did T-Cu users (36.2%). Concentrations of NES in breast milk ranged between 54-135 pmol/liter. The Nestorone implant is a highly effective contraceptive, safe for breastfed infants because the steroid is inactive by the oral route.

[Long-term follow-up of women treated with contraceptive implants of levonorgestrel Norplant]. / Seguimiento a largo plazo de mujeres tratadas con implantes anticonceptivos de levonorgestrel Norplant.

This report describe the long-term follow-up of 376 women who received Norplant implants in the period october 1974 through may 1979. One-hundred-and-ten subjects received replacement implants after variable lengths of use of the first set. The average levonorgestrel plasma levels declined steadily through eight years of use of Norplant capsules (r = -937). Values were 0.35 ng/ml, 0.29 ng/ml and 0.22 ng/ml at treatment years 1, 5 and 8, respectively. Levonorgestrel plasma levels after replacement with a second set of implants were similar to those observed after the first insertion, either when placed in the same site as the first set or in a different area. The levonorgestrel half-life after implant removal was 42 +/- 16 h (X +/- S.E.) and only trace amounts are detected after 96 h. Nineteen pregnancies occurred during 18,530 woman-months of use of the first set of implants, eleven of them during years 6 through 8 of treatment. The Pearl Index for the first years of Norplant implants use was 0.63. No pregnancy has occurred in 5.020 woman-months observed during treatment with a second set of capsules. Fifty-six women (14.9%) out of 376 acceptors of the first implant and 12 (10.9%) out of 110 acceptors of the replacement implants were terminated for other medical reasons, mainly side effects commonly associated with hormonal contraception. Removals for bleeding problems occurred in 5.6% and 3.6% of the acceptors of the first and second implant, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Ectopic pregnancies associated with low dose progestagen-releasing IUDs.

Dimethyl-polysiloxane capsules containing pure progestagens were attached to Tatum's T IUDs and tested in 594 fertile women for contraceptive performance. The control group was represented by 71 women who received identical devices containing barium sulphate instead of steroid and 100 women who received a Copper T-200. The progestagens and the doses tested were megestrol acetate (4.8, 19.2, 26 and 32 micrograms/day; levonorgestrel (2.1, 3.4 and 8.5 micrograms/day); norethindrone (18 micrograms/day); R2323 (28.6 and 45 micrograms/day); and norgestrienone (26 micrograms/day). Twelve pregnancies were diagnosed during 5201 woman-months of exposure accumulated within the first year of use among users of the steroid-bearing IUDs. Five of these were ectopic gestations. Ten pregnancies, all uterine, were detected during 1701 woman-months of exposure in the control group. Intrauterine delivery of progestagens by means of a carrier IUD is effective in decreasing the pregnancy rate but it might effect postovulatory events in a way which increases the rate of tubal implantation. Because of this property, progestagen-releasing IUDs should be limited to doses that assure maximal effectiveness to avoid increasing the risk of ectopic pregnancy.

Clinical trial with subdermal implants containing norgestrienone.

Norgestrienone implants delivering approximately 225 microgram/ day were tested clinically for contraceptive effectiveness and acceptability in 145 women. Five pregnancies occurred in 2259 woman-months of use, one in the 11th month, one in the 15th and three in the 16th month of use. Continuation rate at 12 months was 86.7. The number of bleeding runs and bleeding days was increased in approximately 12% of the subjects. Ten percent of the patients had no bleeding in the first 90 days of treatment. Changes in bleeding pattern led to closures in four cases. Headache and signs of mild androgenicity were among the leading side effects. Blood and urine analysis throughout the study showed normal values of 17 different parameters, but a tendency to lower cholesterolemia not associated with changes in thyroid hormone levels, was observed in several patients. Cortisol was found slightly under the lower normal range in one subject without clinical manifestations of hypoadrenalism. It is concluded that norgestrienone implants should be replaced every twelve months for maximal contraceptive effect and because of their efficacy and good acceptability, evaluation of their long term use is warranted.