Trends and predictors of gestational weight gain among WIC participants in Southern California

Among the gaps identified in the 2009 revision of the Institute of Medicine (IOM) recommendations for gestational weight gain (GWG) was the paucity of GWG data on Hispanic women. Given its wide reach and the high quality of its height/weight measurements, the Special Supplemental Nutrition Program for Women, Infants and Children (WIC) administrative data have significant potential to help fill the existing gaps in GWG surveillance. The objectives of this study were to describe GWG trends and identify predictors of GWG among WIC participants in Southern California, 84% of whom are Hispanic. We examined WIC data on 23,840 Hispanic women with full term pregnancies who enrolled in WIC at first trimester and had their last prenatal WIC visit within one month of their expected delivery date. Overall, 23.9% of women exceeded IOM recommendations. 30% of Hispanic English speakers (HES) exceeded IOM recommendations compared to 18.7% of Hispanic Spanish speakers (HSS). 28.9% of Hispanic mothers less than 20 years of age exceeded IOM guidelines compared to 19.8% of Hispanic mothers 35 or older. Among those who started pregnancy overweight or obese, 30.5% exceeded IOM recommendations vs. 12.1% of those with normal BMI. Multiple logistic regression showed that odds of exceeding the IOM recommendations were 41% lower for HSS vs. HES, decreased by 2% for every one year increase in age, and increased by 6% for every one unit increase in BMI at first trimester. Understanding the trends and identifying predictors of excessive GWG would facilitate the design of targeted interventions.