Racial-ethnic differences in gestational weight gain in a multi-ethnic cohort of women in Los Angeles: Findings from the 2007 Los Angeles Mommy and Baby (LAMB) Survey

Objective: To determine racial/ethnic disparities in gestational weight gain (GWG) in a population-based sample of women who gave birth in Los Angeles County.

Methods: We used data from the 2007 LAMBs, a population–based, mail sample survey based on multistage clustered design. Analyses included unweighted responses of 3,831 women with live births and gestational age of at least 37 completed weeks. Self-reported heights and weights were used to calculate body mass index (BMI kg/m2) and GWG across racial/ethnic groups and compare these to 2009 Institute of Medicine (IOM) recommendations for weight gain by pre-pregnancy BMI.

Results: Nearly half of respondents reported BMI classified as overweight (25.1%) or obese (16.5%), while only 2.8% of respondents reported BMI classified as underweight. Pre-pregnancy BMI varied significantly across racial/ethnic groups (p<.05). Asian/Pacific Islanders had the highest prevalence of underweight (8.4%), while African-Americans and Hispanics had the highest prevalence of overweight and obesity respectively (33.3% and 21.2%). Compared to IOM guidelines for GWG, 31.6% of underweight women, 25.9% of normal weight, 11.8% of overweight and 18.1% obese women gained less than the guidelines, while 23.2%, 31.8%, 53.3%, and 49.6% respectively gained more. Significant racial-ethnic differences were shown in GWG for pre-pregnancy BMI categories (all p-values< 05).

Discussion: Almost half of women entered pregnancy underweight or overweight/obese, and the majority had GWG below or above recommended range. Wide disparities in pre-pregnancy BMI and GWG exist across racial/ethnic groups. Further research on effective clinical and community-based interventions is needed to increase adherence to current GWG guidelines.