Context: Maternal prepregnancy body mass index (pBMI) and offspring's accelerated postnatal growth have adverse consequences for later cardiometabolic health, but it is unknown how these two factors interact.
Objective: To assess the association between maternal pBMI and offspring's metabolic profile at age 5-6 years and determine the role (independent/mediating/moderating) of offspring's postnatal growth in this association.
Design/participants: In total, 1459 mother-child pairs from the prospective ABCD study with known maternal pBMI, offspring postnatal growth (weight and weight-for-length gain) between age 1-3 months (Δ SD score).
Main outcome measures: We analyzed metabolic components of offspring at age 5-6 years, including waist-to-height-ratio (WHtR), systolic/diastolic blood pressure (SBP/DBP), fasting glucose, triglycerides, and high-density lipoprotein-cholesterol values, both individually (Z-scores) and combined (sum Z-scores; metabolic score).
Results: Maternal pBMI was positively associated with offspring's WHtR (β = 0.025; 95% confidence interval [CI], 0.010-0.039), SBP (β = 0.020; 95% CI, 0.005-0.0035), DBP (β = 0.016; 95% CI, 0.000-0.031), and metabolic score (β = 0.078; 95% CI, 0.039-0.118) after adjusting. Adding postnatal growth had no relevant impact on these effect sizes. Postnatal weight gain was independently associated with WHtR (β = 0.199; 95% CI, 0.097-0.300), fasting glucose values (β = 0.117; 95% CI, 0.008-0.227), metabolic score (β = 0.405; 95% CI, 0.128-0.682). Postnatal weight-for-length gain was independently associated with WHtR (β = 0.145; 95% CI, 0.080-0.211), and metabolic score (β = 0.301; 95% CI, 0.125-0.477). An interaction between maternal pBMI and postnatal weight gain was present in the association with SBP (P = .021) and metabolic score (P = .047), and between maternal pBMI and postnatal weight-for-length gain in the association with triglycerides (P = .022) and metabolic score (P = .042).
Conclusions: Both high maternal pBMI and postnatal accelerated growth are associated with adverse metabolic components in early childhood. No evidence was found for a mediating role of postnatal growth. The combination of high maternal pBMI and postnatal accelerated growth amplified individual effects.