(PTFS01-02-25) Racial/Ethnic Disparities in Pre-Pregnancy Obesity: The Role of Residential Segregation in Health Inequities

Objectives: Pre-pregnancy obesity is a major public health concern linked to lifelong adverse outcomes in pregnant individuals and offspring. While neighborhood environment can impact obesity risk, the association of racial/ethnic residential segregation with pre-pregnancy obesity remains unclear.

Methods: This population-based cross-sectional study included pregnant individuals with ≥1 prenatal visit at Kaiser Permanente Northern California in 2011-2021. Residential segregation was assessed based on the address at last menstrual period using the racial/ethnic-specific Getis-Ord Gi* statistic, categorized as low ( < 0), medium (0–1.96), or high ( >1.96). Positive Gi* indicate census tract-level overrepresentation of a racial/ethnic group. Pre-pregnancy body mass index was calculated from weight (kg) within 12 weeks before pregnancy and height (m) within 1 year recorded in electronic health records. Poisson regression estimated relative risk (RR) of pre-pregnancy obesity (≥27.5 kg/m² for Asian/Pacific Islander [API], ≥30 for non-API) vs. healthy weight ( < 23 kg/m² for API, < 25 for non-API). Models adjusted for age, parity, insurance, and pre-pregnancy smoking/alcohol and stratified by race/ethnicity.

Results: Of 388,854 individuals (mean [SD] age 30.9 [5.4] years; 26.7% API, 6.9% Black, 27.8% Hispanic, 38.6% White), pre-pregnancy obesity was most prevalent among Black (40.0%), followed by Hispanic (36.1%), API (23.3%), and White (22.1%) individuals. High vs. low Black and Hispanic segregation were respectively associated with higher obesity risk in API (1.13 [1.11–1.14]; 1.16 [1.15–1.17]), Black (1.06 [1.04–1.08]; 1.08 [1.07–1.10]), Hispanic (1.07 [1.06–1.08]; 1.11 [1.10–1.12]), and White (1.10 [1.09–1.11]; 1.17 [1.16–1.18]) individuals. Conversely, high vs. low White segregation was associated with lower obesity risk in API (RR 0.88 [0.87–0.90]), Black (0.90 [0.88–0.93]), Hispanic (0.87 [0.86–0.88]), and White (0.86 [0.86–0.87]) individuals. API segregation was associated with higher obesity risk in White individuals (1.05 [1.04–1.06]) but not other racial/ethnic groups.

Conclusions: Higher risk of pre-pregnancy obesity in Black and Hispanic segregated neighborhoods vs. lower risk in White segregated neighborhoods underscore structural targets for improving health and advancing reproductive health equity.

Funding Sources: NIH