Prevalence and Social and Built Environmental Determinants of Maternal Prepregnancy Obesity in 68 Major Metropolitan Cities of the United States, 2013–2016

Objective. Maternal prepregnancy obesity is related to increased maternal morbidity and mortality and poor birth outcomes. However, prevalence and risk factors for prepregnancy obesity in US cities are not known. This study examines the prevalence and social and environmental determinants of maternal prepregnancy obesity (BMI ≥30), overweight/obesity (BMI ≥25), and severe obesity (BMI ≥40) in the 68 largest metropolitan cities of the United States. Methods. We fitted logistic and Poisson regression models to the 2013–2016 national vital statistics birth cohort data (N = 3,083,600) to derive unadjusted and adjusted city differentials in maternal obesity and to determine social and environmental determinants. Results. Considerable disparities existed across cities, with the prevalence of prepregnancy obesity ranging from 10.4% in San Francisco to 36.6% in Detroit. Approximately 63.0% of mothers in Detroit were overweight or obese before pregnancy, compared with 29.2% of mothers in San Francisco. Severe obesity ranged from 1.4% in San Francisco to 8.5% in Cleveland. Women in Anchorage, Buffalo, Cleveland, Fresno, Indianapolis, Louisville, Milwaukee, Oklahoma City, Sacramento, St Paul, Toledo, Tulsa, and Wichita had >2 times higher adjusted odds of prepregnancy obesity compared to those in San Francisco. Race/ethnicity, maternal age, parity, marital status, nativity/immigrant status, and maternal education were important individual-level risk factors and accounted for 63%, 39%, and 72% of the city disparities in prepregnancy obesity, overweight/obesity, and severe obesity, respectively. Area deprivation, violent crime rates, physical inactivity rates, public transport use, and access to parkland and green spaces remained significant predictors of prepregnancy obesity even after controlling for individual-level covariates. Conclusions. Substantial disparities in maternal prepregnancy obesity among the major US cities remain despite risk-factor adjustment, with women in several Southern and Midwestern cities experiencing high risks of obesity. Sound urban policies are needed to promote healthier lifestyles and favorable social and built environments for obesity reduction and improved maternal health.

Are observed associations between a high maternal prepregnancy body mass index and offspring IQ likely to be causal?

BackgroundA high maternal prepregnancy body mass index has been associated with lower offspring IQ, but it is unclear if the relationship is causal. To explore this, our objectives were to compare maternal and paternal estimates and to assess whether certain factors mediate the association.MethodsWe analysed data from the Avon Longitudinal Study of Parents and Children, which initially recruited 14 541 women residing in Avon, UK, with an expected date of delivery in 1991–1992. Data were collected during and after pregnancy by questionnaire, medical record abstraction and clinical assessment. At approximately 8 years of age, psychologists administered an abbreviated form of the Wechsler Intelligence Scale for Children-III. We fit multivariable logistic regression models to estimate parental prepregnancy obesity and overweight–offspring IQ associations. Counterfactually defined indirect (mediated) effects of maternal prepregnancy obesity on offspring IQ were estimated through path analysis.ResultsAmong 4324 mother–father–child triads and using normal weight as the referent, we observed consistently stronger associations for maternal prepregnancy obesity and offspring performance IQ (eg, adjusted β (95% CI)=−3.4 (−5.7 to −1.2) vs −0.97 (−2.9 to 0.96) for paternal obesity). The indirect effects of maternal obesity on offspring IQ through pathways involving gestational weight gain and duration of breastfeeding were small but significant.ConclusionOur findings are consistent with a weak biologic effect of maternal adiposity in pregnancy on offspring performance IQ. Given the growing prevalence of obesity worldwide, more evidence is needed to resolve the correlation versus causation debate in this area.