The relationship between body mass index and unintended pregnancy: results from the 2002 National Survey of Family Growth

BackgroundThe study was conducted to characterize the relationship between body mass index (BMI) and unintended pregnancy, contraceptive use patterns, and perceived fertility.MethodsThis study employed a cross-sectional, nationally representative database (2002 National Survey of Family Growth). Unintended pregnancy was compared among BMI groups [normal (<25 m/kg2), overweight (25–30 m/kg2) and obese (>30 m/kg2)]. Analyses also evaluated the association between demographic, socioeconomic, behavioral and health-related variables and BMI. Multiple logistic regression with adjustment for sampling design was used to measure associations of interest.ResultsBMI data were available from 6690 nonpregnant women. Of these, 3600 (53.6%) were normal weight, 1643 (25%) were overweight and 1447 (21.4%) were obese. Compared to women with normal BMIs, the risk of unintended pregnancy in the last 5 years did not differ among overweight [adjusted OR 0.95 (95% CI 0.77–1.17)] or obese [adjusted OR 0.87 (95% CI 0.70–1.09)] women. There were no differences in contraceptive use patterns or perceived fertility among BMI groups.ConclusionData from the 2002 NSFG do not support an association between obesity and unintended pregnancy.