OBJECTIVE: Many observational studies indicate higher oral contraceptive failure among obese women, but most clinical trials and physiologic studies do not support these differences. Limited data indicate higher failure rates among obese contraceptive patch users. Data regarding contraceptive vaginal ring performance in obese women are needed. STUDY DESIGN: Twenty normal weight (body mass index [BMI] 19.0-24.9; median, 21.65) and 20 obese (BMI 30.0-39.9; median, 33.7) women enrolled in a prospective study of ethinyl estradiol (EE(2)) and etonorgestrel pharmacokinetics and of ovarian follicle development, endometrial thickness, and bleeding patterns, all measured biweekly during the second cycle of contraceptive vaginal ring use. RESULTS: Thirty-seven women completed follow-up. Mean day 0-21 EE(2) concentrations were lower among obese vs normal weight women (15.0 vs 22.0 pg/mL, respectively, P = .004), whereas etonorgestrel concentrations were similar (1138 vs 1256 pg/mL, respectively, P = .39). Follicular development was minimal in both groups, with only 5 women achieving a maximum follicle diameter >13 mm at any time during 3 weeks follow-up (3 normal weight and 2 obese women); these women had serum progesterone levels <1.0. Obese women reported more bleeding or spotting than normal weight women (3.6 vs 1.4 days, respectively, P = .01). CONCLUSION: Although obese women had lower EE(2) levels during contraceptive vaginal ring use, they had excellent suppression of ovarian follicle development, similar to normal weight women. This predicts that contraceptive vaginal ring effectiveness will be similar in women with a BMI up to 39.9. The lower serum EE(2) levels in the obese women may explain the greater reported bleeding or spotting days.
OBJECTIVE: Many observational studies indicate higher oral contraceptive failure among obesewomen, but most clinical trials and physiologic studies do not support these differences. Limited data indicate higher failure rates among obese contraceptive patch users. Data regarding contraceptive vaginal ring performance in obesewomen are needed. STUDY DESIGN: Twenty normal weight (body mass index [BMI] 19.0-24.9; median, 21.65) and 20 obese (BMI 30.0-39.9; median, 33.7) women enrolled in a prospective study of ethinyl estradiol (EE(2)) and etonorgestrel pharmacokinetics and of ovarian follicle development, endometrial thickness, and bleeding patterns, all measured biweekly during the second cycle of contraceptive vaginal ring use. RESULTS: Thirty-seven women completed follow-up. Mean day 0-21 EE(2) concentrations were lower among obese vs normal weight women (15.0 vs 22.0 pg/mL, respectively, P = .004), whereas etonorgestrel concentrations were similar (1138 vs 1256 pg/mL, respectively, P = .39). Follicular development was minimal in both groups, with only 5 women achieving a maximum follicle diameter >13 mm at any time during 3 weeks follow-up (3 normal weight and 2 obesewomen); these women had serum progesterone levels <1.0. Obesewomen reported more bleeding or spotting than normal weight women (3.6 vs 1.4 days, respectively, P = .01). CONCLUSION: Although obesewomen had lower EE(2) levels during contraceptive vaginal ring use, they had excellent suppression of ovarian follicle development, similar to normal weight women. This predicts that contraceptive vaginal ring effectiveness will be similar in women with a BMI up to 39.9. The lower serum EE(2) levels in the obesewomen may explain the greater reported bleeding or spotting days.
Authors: Miriam Zieman; John Guillebaud; Edith Weisberg; Gary A Shangold; Alan C Fisher; George W Creasy Journal: Fertil Steril Date: 2002-02 Impact factor: 7.329
Authors: William D Schlaff; Anne M Lynch; Heather D Hughes; Marcelle I Cedars; Deborah L Smith Journal: Am J Obstet Gynecol Date: 2004-04 Impact factor: 8.661
Authors: Laureen M Lopez; Alissa Bernholc; Mario Chen; Thomas W Grey; Conrad Otterness; Carolyn Westhoff; Alison Edelman; Frans M Helmerhorst Journal: Cochrane Database Syst Rev Date: 2016-08-18