Secondary Logo

Journal Logo

Papers on Current Clinical and Basic Investigation: Tuesday, May 9, 2006: Contraception/Family Planning

Higher Body Weight and Body Mass Index Are Not Associated With Reduced Efficacy in Ortho Tri-Cyclen Lo Users

Zhang, Huabin F. MD, MPH; LaGuardia, Katherine D. MD, MPH; Creanga, Dana L. PhD

Author Information
  • Free


To examine associations between oral contraceptive failure and body weight or body mass index (BMI) among Ortho Tri-Cyclen Lo users.


A retrospective analysis of Ortho Tri-Cyclen Lo phase III efficacy data were performed assessing the distribution of pregnancies by weight (method-failure and “total” pregnancies [method failure and user failure]). Relative pregnancy risk (RR) was examined using the Cox proportional hazard model.


Of the 20 “total” pregnancies that occurred with Ortho Tri-Cyclen Lo subjects (ITT = 1,673; 11,003 cycles; weight range 90–240 lb), 14 were classified as method failures and 6 as user failures, giving a cumulative pregnancy probability of 1.9% for “total” and 1.5% for method failure only. Both method failure and “total” pregnancies were evenly distributed over body weight deciles (range 0–4 pregnancies). In the highest decile (> 175 lb, n = 174), 2 method-failure and 2 user-failure pregnancies occurred. Among women 198 pounds and over (n = 55), there was 1 user-failure and no method-failure pregnancy. Ortho Tri-Cyclen Lo users with body weight of 155 pounds (75% percentile) and over (n = 435) did not experience significantly higher pregnancy risk compared with those less than 155 pounds with either method-failure pregnancies (RR 1.03, 95% confidence interval [CI] 0.32–3.32, P = .95) or “total” pregnancies (RR 1.42, 95% CI 0.57–3.56, P = .46). Consistent results were found when examining other weight criteria (median weight ≥ 139 lb versus < 139 lb, > 175 lb versus ≤ 175 lb, and higher body weight criterion ≥ 198 lb versus < 198 lb) and BMI criteria (≥ 25 versus < 25).


Ortho Tri-Cyclen Lo is not associated with elevated pregnancy risk among higher weight women.

© 2006 The American College of Obstetricians and Gynecologists