Conflicting research findings on the association of obesity and pregnancy intention may be due to their collective definition of obesity at a body mass index of 30 kg/m2 or greater. However, obese women with a BMI of 40 kg/m2 or greater may be both behaviorally and clinically different from obese women with a lower BMI. This study reexamines this relationship, stratifying by class of obesity; the study also explores variations in contraceptive use by class of obesity given their potential contribution to the incidence of unintended or unwanted pregnancy.
This study combined data from the 2006 through 2010 and 2011 through 2013 US National Survey of Family Growth. Pregnancy intention (intended, mistimed, unwanted) and current contraceptive use (no method, barrier, pill/patch/ring/injection, long-acting reversible contraceptive, sterilization) were compared across body mass index categories: normal (18.5–24.9 kg/m kg/m2), overweight (25.0–29.9), obese class 1 (30.0–34.9 kg/m2), class 2 (35.0–39.9 kg/m2), and class 3 (≥40 kg/m2, severe obesity). Weighted multinomial logistic regressions were refined to determine independent associations of body mass index class and pregnancy intention, as well as contraceptive method, controlling for demographic, socioeconomic, and reproductive factors.
Body mass index data were available for 9,848 nonpregnant, sexually active women who reported not wanting to become pregnant. Women with class 3 obesity had significantly greater odds of mistimed (adjusted odd ratio [aOR], 1.67; 95% confidence interval [CI], 1.02–2.75) or unwanted (aOR, 1.96; 95% CI, 1.15–3.32) pregnancy compared with normal weight women. Women with class 2 or 3 obesity were more likely to not be using contraception (aOR, 1.53–1.62; 95% CI, 1.04–2.29). Although women with class 2 obesity were more likely to be using long-acting reversible contraceptive methods and sterilization over short-acting hormonal methods (aOR, 1.67; 95% CI, 1.08–2.57; aOR, 2.05; 95% CI,1.44–2.91), this association was not observed among women with class 3 obesity.
Women with class 3 obesity are at greater risk of unintended pregnancy and are less likely to be using contraception than normal weight women. Whether these findings are related to patient and/or provider barriers that are not as visible among women with class 1 and class 2 obesity warrants further investigation.
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Dr. Brian T. Nguyen, MD, MSCP, is an assistant professor within the Department of Obstetrics and Gynecology at the University of Southern California and assistant program director for the Fellowship in Family Planning. Dr. Nguyen’s research addresses reproductive health disparities, with interest in the contributions of gender-based and structural barriers.
Jennifer L. Elia, DrPH, MPH, is an Assistant Researcher in the Department of Obstetrics, Gynecology, & Women’s Health at the University of Hawai‘i John A. Burns School of Medicine. Her research interests include health disparities, pregnancy intention, contraceptive use, and community engagement.
Cathrine Y. Ha is an undergraduate student at USC studying Health & Human Sciences and Gender Studies. As an aspiring Obstetrician Gynecologist, she is interested in how gender operates both positively and negatively in both healthcare and medicine.
Dr. Bliss E. Kaneshiro, MD, MPH, is a board-certified Obstetrician Gynecologist, Program Director of the Family Planning Fellowship, and Chief of the Family Planning Division at the University of Hawaii. She is also the Medical Director of Family Planning for the Hawaii State Department of Health.
Published online: November 13, 2017
Accepted: September 20, 2017
Received in revised form: September 13, 2017
Received: April 15, 2017
Conflicts of Interest: None.
Financial Statement: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
© 2017 Jacobs Institute of Women's Health. Published by Elsevier Inc.