Neonatal outcomes following a preconception lifestyle intervention in people at risk of gestational diabetes: secondary findings from the BEFORE THE BEGINNING randomised controlled trial

ObjectivesGestational 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 randomised controlled trial. MethodsPeople (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 hours/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 primary outcome in this report was the proportion of infants with birth weight > 4.0 kg. ResultsAmong 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 =.367). Mean birth weight did not differ significantly between groups (mean difference -159.3 g, 95% confidence interval - 375.7 to 57.2, p =.148). No significant between-group differences were found for additional neonatal, birth-related, or early postnatal body composition outcomes. ConclusionIn this secondary analysis, a preconception lifestyle intervention did not reduce the risk of macrosomia or affect neonatal body composition. Trial registrationClinicalTrials.gov NCT04585581.