Aims: Diabetes in pregnancy (DIP) and maternal overweight/obesity may have persistent effects on offspring adiposity. We aimed to examine the independent and combined associations of DIP and maternal overweight/obesity with offspring adiposity from early-childhood to late-adolescence.
Methods: We analysed population-based prospective data from the B-cohort (n=2,436 children, aged 0-1 at baseline in 2004) and the K-cohort (n=2,245, aged 4-5 at baseline) of the Longitudinal Study of Australian Children. DIP and maternal BMI were self-reported at baseline, and offspring height, weight and body fat were measured at 2-year intervals. Associations of DIP and maternal overweight/obesity with offspring BMI, fat mass index (FMI) and fat-free mass index (FFMI) between ages 2 and 16 were examined using weighted generalised estimating equations and adjusted for maternal characteristics, paternal BMI, and offspring gestational age at delivery, age and sex. Product terms were added to the models to examine interactions between DIP and maternal BMI, and changes in associations with increasing offspring age. Interaction tests indicated no cohort differences, and data were therefore combined (n=4,681).
Results: Both DIP (5.5%) and maternal BMI (44.4% overweight/obese) were associated with higher offspring BMI: 0.49 kg/m2 (95% CI 0.04-0.95) and 1.17 kg/m2 (0.99-1.34), respectively. Mutual adjustment for both maternal risk factors attenuated the association for DIP (0.22 kg/m2 [-0.24-0.67]), but not for BMI (1.17 kg/m2 [0.99-1.35]). Maternal overweight/obesity was associated with a 2-fold higher risk of offspring overweight/obesity (relative risk 1.90 [1.73-2.10]). The differences in BMI between offspring born to mothers with normal weight compared with overweight/obesity became larger with increasing offspring age (p-interaction=<0.0001). There was no significant interaction between DIP and maternal overweight/obesity (p-interaction=0.42). Similar results were found when examining the associations with offspring FMI and FFMI.
Conclusions: Maternal overweight/obesity was strongly associated with poorer adiposity measures in childhood and adolescence, whereas the association between DIP and offspring adiposity was largely explained by maternal BMI. Future studies are needed to determine if preconception weight loss improves offspring adiposity trajectories.