Contraceptive Failure Rates of Etonogestrel Subdermal Implants in Overweight and Obese Women
Obstetrics and Gynecology, 06/26/2012
Xu H et al. – The authors found no decrease in the effectiveness of the implant in overweight or obese women. The implant may be offered as a first–line contraceptive method to any woman seeking a reversible and reliable birth control method.Methods
- The Contraceptive CHOICE Project is a large prospective cohort study designed to promote the use of long–acting reversible contraceptive methods to reduce unintended pregnancies in the St Louis region.
- Participants are provided reversible contraception of their choice at no cost.
- The authors collected baseline height and weight of each participant.
- During each survey, participants were asked about missed menses and possible pregnancies.
- Any participant who suspected a pregnancy was asked to come in for urine pregnancy testing.
- Analysis includes the first 8,445 participants enrolled in CHOICE of which 1,168 chose the implant and 4,200 chose the IUD.
- Student's t test, χ2 test, and Kaplan–Meier survival curves were used to perform statistical analyses to estimate failure rates in overweight and obese women using the implant and IUDs.
- Of the women choosing the implant, 28% were overweight and 35% were obese.
- Of the women who chose an IUD, 27% were overweight and 35% were obese.
- The 3–year cumulative failure rates for implant and IUD users were less than one per 100 women–years and did not vary by body mass index.