OBJECTIVE: To assess whether prepregnancy body mass index (BMI) is independently associated with the timing of pregnancy recognition and initiation of prenatal care.
METHODS: Data from 2009 to 2010 were obtained from the Centers for Disease Control and Prevention's Pregnancy Risk Assessment Monitoring System. The 30 participating states contacted sampled mothers 2-4 months after delivery and had them complete the standardized Pregnancy Risk Assessment Monitoring System questionnaire. Prepregnancy BMI was calculated from the participants' self-reported prepregnancy weight and height. Timing of pregnancy recognition and initiation of prenatal care were also self-reported on the questionnaire.
RESULTS: Among the 72,913 participants, 69,872 (96%) met the eligibility criteria for analysis. After adjustment for maternal race, ethnicity, smoking status in the 3 months before pregnancy, pregnancy intentions, insurance status, maternal age, marital status, maternal education, and parity, there was no association between prepregnancy BMI status and the week of pregnancy recognition. Obese women initiated prenatal care 0.20 weeks earlier on average compared with normal-weight women, although the difference was not clinically important (mean difference -0.20, 95% confidence interval [CI] -0.38 to -0.03). When examining the odds of receiving late or no prenatal care, there was no association with prepregnancy BMI. Uninsured women, however, reported initiating prenatal care almost 3 weeks later on average than privately insured women (mean difference 2.83, 95% CI 2.27-3.38) and had a more than fourfold increased odds of receiving late or no prenatal care (odds ratio 4.04, 95% CI 3.13-5.23).
CONCLUSION: Prepregnancy BMI was not meaningfully associated with a delay in pregnancy recognition or with increased odds of receiving late or no prenatal care.