Feasibility of an Obesity Prevention Program for Latino Families from First Trimester of Pregnancy to Child Age 18 Months and Predictors of Program Attendance

<b><i>Background:</i></b> The high prevalence of obesity in Latino families with low income necessitates prevention beginning in pregnancy and continuing through infancy. Due to systemic inequities, adverse social determinants of health (SDoH) and mental health symptoms may limit program efficacy by presenting barriers to attendance. We sought to assess: (1) the feasibility of the Starting Early Program (StEP) Prenatal, a 17-session intervention beginning early in pregnancy and continuing to 18 months postpartum; and (2) the effects of adverse SDoH (material hardship, low social support) and mental health symptoms (depression, anxiety, stress) on program attendance. <b><i>Methods:</i></b> We conducted a single-arm feasibility trial of StEP Prenatal, enrolling from December 2018 to February 2020 (<i>n</i> = 231). We assessed feasibility (recruitment, retention, fidelity, attendance) and direct and interactive effects of adverse SDoH and mental health symptoms on attendance. We used zero-inflated Poisson regression, adjusting for maternal age, marital status, nativity, education, and pandemic timing. <b><i>Results:</i></b> We recruited 57% of eligible participants, with 213 remaining eligible to receive the full program. Retention was 75%. Median fidelity for group format was 64%; median attendance per session was 69%; median number of program sessions attended was 13. Baseline material hardship and high perceived stress predicted approximately one additional session attended. Similar effects were seen for low social support in the absence of anxiety symptoms. <b><i>Conclusion:</i></b> Despite pandemic disruptions, StEP Prenatal was feasible to deliver and participants with adverse SDoH at baseline were particularly motivated to attend. Futures studies should tailor programs to baseline SDoH and test flexible implementation models.