Neonatal Outcomes Following a Preconception Lifestyle Intervention in People at Risk of Gestational Diabetes: Secondary Findings from the BEFORE THE BEGINNING Randomized Controlled Trial.

Objectives

Gestational diabetes mellitus (GDM), particularly when combined with overweight or obesity, is associated with adverse neonatal outcomes such as high birth weight and increased adiposity. We determined the effect of a preconception lifestyle intervention initiated before and continued throughout pregnancy on neonatal, birth-related, and body composition outcomes at birth and 6-8 weeks of age in children of participants in the BEFORE THE BEGINNING randomized controlled trial.

Methods

People (N = 167) at increased risk of GDM and planning pregnancy were randomly allocated 1:1 to intervention or control. The intervention included time-restricted eating and exercise training. Time-restricted eating involved consuming all energy within ≤10 h/day, ≥5 days per week, and the amount of exercise was set using a heart rate-based physical activity metric (Personal Activity Intelligence, PAI), with the goal of ≥100 weekly PAI points. The main outcome of interest in this report was the proportion of infants with birth weight > 4.0 kg.

Results

Among 106 live births, 21% (11/53) of infants in the intervention group and 28% (15/53) in the control group had birth weight > 4 kg (p = 0.367). Mean birth weight did not differ significantly between groups (mean difference -159.3 g, 95% confidence interval -375.7 to 57.2, p = 0.148). No significant between-group differences were found for additional neonatal, birth-related, or early postnatal body composition outcomes.

Conclusions

In this secondary analysis, we found no evidence of effects of a preconception lifestyle intervention on the risk of macrosomia or neonatal body composition.