Targeting pregnancy-related weight gain to reduce disparities in obesity: Baseline results from the Healthy Babies trial

Obesity affects African American women more than any other group in the US. Pregnancy represents a critical life stage of heightened vulnerability for new or persistent obesity, yet few interventions have been effective in reducing excessive gestational weight gain among African American women. We describe the design and baseline findings of Healthy Babies, a two-arm randomized controlled trial testing a mobile health intervention to minimize excessive gestational weight gain versus usual care in this high risk group.

African American women in early pregnancy were recruited from two large obstetric practices as well as Philadelphia Women, Infants, and Children's clinics. Participants randomized to the intervention received behavior change goals, daily text messages with feedback, web-based weight gain graphs, health coaching, and a Facebook support group. Data collection included baseline (<22 weeks' gestation), 36-38 weeks' gestation, and 6-month postpartum anthropometric measures and assessments of demographics, contextual factors and behavioral targets. The primary outcome was prevalence of excessive gestational weight gain.

Among participants at baseline (n = 262), the majority met criteria for obesity (63%), were multiparous (62%), single (77%), and were on average 25.6 ± 5.4 years old with a gestational age of 13.9 ± 4.1 weeks. While 82% completed high school, 61% met criteria for inadequate health literacy. Nearly 20% were food insecure. Eighty-eight percent reported a gestational weight gain goal discordant with Institute of Medicine guidelines. There were no significant differences in baseline characteristics between study arms.

Participants represent a high-risk group for excessive gestational weight gain with demonstrated need for intervention.