Two-year performance of a Nestorone-releasing contraceptive implant: a three-center study of 300 women.
A 2-year trial of a single Nestorone (NES) rod implant was conducted at three Latin American centers, each enrolling 100 women. We studied the safety, effectiveness and acceptability of this progestin-releasing contraceptive implant. Three pregnancies occurred, the last at 18 months of use. Because no pregnancies were expected in the first 18 months, the trial was halted. At that time, 224 women had completed at least 18 months of use, and 99 women had used the implant for more than 24 months. Few participants used adjunctive contraception between the time the study was halted and the time they had their implant removed. No additional pregnancies occurred before the removal of the last implant. The 2-year cumulative pregnancy rate was 1.7 per 100 with a Pearl index of 0.6 per 100 for the 2-year period. The 1-year and 2-year continuation rates were 80.5 and 66.7 per 100, respectively. Menstrual and medical disturbances were the principal reasons for discontinuation, followed by planned pregnancy. Headache and weight gain frequently led to discontinuation. The NES implant had little important effect on most clinical chemistry and lipid parameters. Over the study course, the mean change in hemoglobin was <1%. Slight modification of the design of this single 2-year implant, restoring features previously examined in clinical trials, is likely to improve its effectiveness. A single NES implant appears to provide acceptable contraception for women.
Sivin
Irving
I
Center for Biomedical Research, Population Council, 1230 York Avenue, New York, NY 10021, USA. sivin@popcbr.rockefeller.edu
Croxatto
Horacio
H
Bahamondes
Luis
L
Brache
Vivian
V
Alvarez
Francisco
F
Massai
Rebeca
R
Schechter
Janet
J
Ranta
Sirpa
S
Kumar
Narender
N
Wu
Esther
E
Tejeda
Ana Sofia
AS
Reyes
Veronica
V
Travers
Elaine
E
Allen
Arthur
A
Moo-Young
Alfred
A
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001938:Brazil; D016009:Chi-Square Distribution; D003271:Contraceptive Agents, Female / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D004343:Drug Implants; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008599:Menstruation Disturbances / Q000139:chemically induced; D009653:Norprogesterones / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D010352:Patient Dropouts / Q000706:statistics & numerical data; D011247:Pregnancy; D011275:Pregnancy, Unwanted / Q000706:statistics & numerical data; D016896:Treatment Outcome
D003271:Contraceptive Agents, Female; D004343:Drug Implants; D009653:Norprogesterones; C029167:ST 1435