The weight a woman gains during pregnancy, known as gestational weight gain (GWG), has important health implications for both mother and child (1). The Institute of Medicine (IOM) provides GWG recommendations that promote optimal health by balancing risks associated with too much or too little GWG and are specific to a woman's prepregnancy body mass index (BMI; weight [kg]/height [m] 2)(1). In a recent study, 21% of pregnant women gained less than the recommended amount of weight, and 47% gained more than the recommended amount; however, state-specific prevalence was not examined (2). To estimate state-specific prevalence of GWG below, within, and above recommendations (referred to as inadequate, appropriate, and excessive, respectively), CDC analyzed 2013 birth data for US resident women who delivered full-term (37–41 weeks gestation), singleton infants from 43 jurisdictions (41 states, New York City, and the District of Columbia [DC]) that used the 2003 revised birth certificate, which collects maternal height, prepregnancy weight, and delivery weight. In addition, 2012 data from the Pregnancy Risk Assessment Monitoring System (PRAMS) were analyzed to estimate prevalence for five states with available data that had not yet adopted the 2003 birth certificate. Overall, 32.1% of women had appropriate GWG. States varied in prevalence of inadequate (range= 12.6%–25.5%), appropriate (range= 26.2%–39.0%), and excessive (range= 38.2%–54.7%) GWG. The prevalence of inadequate GWG was≥ 20% in 20 states and New York City; the prevalence of excessive GWG was≥ 50% in 17 states. Stratification by prepregnancy BMI category indicated variation by state persisted; notably, overweight women had the highest prevalence of excessive GWG in nearly every state. Given the high prevalence of excessive GWG and its associated risks, including macrosomia and maternal obsesity (1), effective interventions to prevent excessive GWG during pregnancy are needed.

The primary data source was 2013 National Vital Statistics System birth data, a census of all births, for jurisdictions using the 2003 revision of the US Standard Certificate of Live Birth,* which collects the maternal height, prepregnancy weight, and delivery weight data needed to examine GWG in relation to the BMI-specific IOM recommendations. Height and weight data are self-reported or abstracted from the medical record. The previous (1989) birth certificate version reports only total GWG (self-reported or abstracted from the medical record), and therefore, cannot be used to examine GWG in relation to BMI-specific recommendations. As of January 1, 2013, 41 states,† New York City, and DC had adopted the 2003 birth certificate. Data from PRAMS for 2012 were analyzed for five states § that had yet to transition to the 2003 birth certificate and that had PRAMS data available.¶ PRAMS is an ongoing, state-based surveillance system that systematically surveys a stratified, random sample of mothers from birth certificates.** At approximately 4 months postpartum, participating mothers complete a questionnaire that assesses pregnancy-related health characteristics, including height and prepregnancy weight. Questionnaire data are linked with birth certificate data, including GWG, and are weighted to represent all women delivering live infants in each state. For this report, women were included if they were US residents delivering full-term, singleton infants and did not have missing values for prepregnancy weight, height, or GWG. The resulting sample represents approximately 79% of annual US births.