Racial/ethnic variations in gestational weight gain: a population-based study in Ontario

To explore inadequate and excessive gestational weight gain (GWG) among pregnant women of different racial/ethnic backgrounds in Ontario, Canada. A population-based retrospective cohort study was conducted among women who had prenatal screening and had a singleton birth in an Ontario hospital between April 2016 and March 2017. We estimated adjusted risk ratios (aRR) of racial/ethnic differences for inadequate or excessive GWG using multinomial logistic regression models. Interaction effects were examined to determine whether racial/ethnic difference in GWG varied by pre-pregnancy body mass index (BMI). Among 74,424 women, the prevalence of inadequate GWG in White, Asian, and Black women was 15.7%, 25.8%, and 25.0%, and excessive GWG was 62.8%, 45.5%, and 54.7%, respectively. There were significant interaction effects between race/ethnicity and pre-pregnancy BMI for inadequate GWG (Wald p < 0.01) and excessive GWG (Wald p < 0.01). Compared with White women, Asian women had higher risk of inadequate GWG and lower risk of excessive GWG in all weight classes, and Black women had higher risk of inadequate GWG and lower risk of excessive GWG if their BMI was normal, overweight, or obese. Variations in unhealthy GWG by pre-pregnancy weight classes among Ontario White, Asian and Black women were observed. Individualized counseling regarding appropriate GWG is universally recommended. Additional consideration of racial/ethnic variations by maternal weight classes may help to promote healthy GWG in Canada.