Differential effects of a stakeholder-informed intensive perinatal eHealth behavioral weight gain intervention between non-Hispanic Black and non-Hispanic White individuals: a secondary analysis of a randomized clinical trial.

Aberrant gestational weight gain (GWG) increases the risk of adverse perinatal outcomes such as preterm birth; these poor outcomes are disproportionately higher in non-Hispanic Black individuals relative to White individuals. Lifestyle interventions effectively manage GWG but often fail to reach those most in need. "Healthy Beginnings," a co-developed intensive perinatal eHealth behavioral weight gain intervention, successfully enrolled individuals from disadvantaged, underrepresented communities living in neighborhoods characterized by higher socioeconomic disadvantage and greater maternal and social vulnerability. However, it is unclear whether the intervention demonstrated effectiveness in this population. To evaluate potential treatment heterogeneity between non-Hispanic Black and White individuals differentially experiencing systemic inequalities while enrolled in the trial. This analysis examined data from a statewide parallel-arm randomized clinical trial that demonstrated the effectiveness of a GWG intervention tailored for pregnant individuals enrolled in the Special Supplemental Nutrition Program for Women, Infants, and Children. Participants identifying as non-Hispanic Black (N = 201) or non-Hispanic White (N = 109) were included in this secondary analysis to evaluate intervention effectiveness between these groups on GWG, body composition, dietary intake, physical activity, and perinatal outcomes. Intervention-by-race interaction effects were not statistically significant for any outcome. Non-Hispanic Black participants in the Intervention Group exhibited attenuated weekly GWG (-0.10 kg/week; 95% CI: -0.18 to -0.01) and fat mass gain (-1.7 kg; 95% CI: -3.1 to -0.3) compared to Usual Care. Preterm birth incidence was lower in non-Hispanic Black participants receiving the intervention (adjusted odds ratio 0.38; 95% CI: 0.16-0.90) compared to Usual Care. No intervention effects in White participants were observed. This multicomponent eHealth lifestyle intervention effectively attenuated GWG and lowered incidence of preterm birth in non-Hispanic Black but not non-Hispanic White participants, suggesting potential for mitigating racial disparities in pregnancy health.