Marked Disparities in Pre-Pregnancy Obesity and Overweight Prevalence among US Women by Race/Ethnicity, Nativity/Immigrant Status, and Sociodemographic Characteristics, 2012-2014

This study examines racial/ethnic, nativity, and sociodemographic disparities in the prevalence of pre-pregnancy obesity and overweight in the United States. Logistic regression was fitted to the 2012-2014 national birth cohort data to derive unadjusted and adjusted differentials in pre-pregnancy obesity (BMI 30), severe obesity (BMI 40), and overweight/obesity (BMI 25) prevalence among 10.4 million US women of childbearing age. Substantial racial/ethnic differences existed, with pre-pregnancy obesity rates ranging from 2.6% for Chinese and 3.3% for Vietnamese women to 34.9% for American Indians/Alaska Natives (AIANs) and 60.2% for Samoans. Pre-pregnancy overweight/obese prevalence ranged from 13.6% for Chinese women to 61.7% for AIANs and 86.3% for Samoans. Compared to non-Hispanic whites, women in all Asian subgroups had markedly lower risks of pre-pregnancy obesity, severe obesity, and overweight/obesity, whereas Samoans, Hawaiians, AIANs, blacks, Mexicans, Puerto Ricans, and Central/South Americans had significantly higher risks. Immigrant women in each racial/ethnic group had lower rates of pre-pregnancy obesity than the US-born. Sociodemographic risk factors accounted for 33-47% of racial/ethnic disparities and 12-16% of ethnic-immigrant disparities in pre-pregnancy obesity and overweight/obesity. Further research is needed to assess the effects of diet, physical inactivity, and social environments in explaining the reported ethnic and nativity differences in pre-pregnancy obesity.