No Effect of Prepregnancy Weight Loss Intervention on Child Weight up to Age 5

Background: Our aim was to examine if a prepregnancy lifestyle intervention impacted early childhood weight gain. Methods: A 5-year longitudinal observational follow-up of children born to women aged 18–40 years with body mass index (BMI) ≥27 kg/m 2 who participated in Prepare, a randomized clinical trial testing a prepregnancy lifestyle intervention vs. usual care control. Data were collected from birth through ages 36–60 months using electronic medical record (EMR) chart abstraction, a single in-person or virtual visit, and surveys. Results: Of the 165 children born to Prepare participants, 133 (70 in intervention and 63 in usual care) contributed BMI data to the PrepareD observational follow-up study. Longitudinal BMI trajectories from birth to age 5 demonstrated no significant differences between study arms ( p = 0.06). There were no significant differences in mean BMI (17.0 ± 1.7 vs. 16.7 ± 1.7; p = 0.44), BMI z-score (0.30 ± 1.12 vs. 0.02 ± 1.19; p = 0.40), BMI percentile (56.2 ± 29.8 vs. 50.2 ± 31.4; p = 0.56), or conditional weight gain (0.10 ± 1.07 vs. −0.17 ± 0.95; p = 0.19) between intervention and control arms, respectively, at age 12 months. There were also no significant differences in mean BMI (16.4 ± 1.7 vs. 16.2 ± 1.6; p = 0.61), BMI z-score (0.43 ± 1.07 vs. 0.23 ± 1.17; p = 0.44), BMI percentile (56.2 ± 29.8 vs. 57.1 ± 32.5; p = 0.39), or conditional weight gain (0.01 ± 1.08 vs. −0.09 ± 0.95; p = 0.51) at 36–60 months. Conclusions: A prepregnancy lifestyle intervention did not influence childhood weight trajectory. Focusing lifestyle interventions solely on prepregnancy maternal obesity may not be sufficient to influence childhood growth. Trials that examine lifestyle interventions that offer support before, during, and after pregnancy are needed to determine if intervening before conception can interrupt the intergenerational cycle of obesity.