Mid-pregnancy weight gain is associated with offspring adiposity outcomes in early childhood

Background: Gestational weight gain (GWG) has been linked to childhood obesity. However, it is unclear if the timing of weight gain influences offspring body composition. A secondary analysis of a clinical trial examined the influence of total, early, and mid-pregnancy GWG on adiposity outcomes in 186 children at birth, 1, 3, and 5 years.

Methods: Early (<15 weeks) and mid-pregnancy GWG (15-32 weeks) were assessed. Anthropometrics and abdominal ultrasound were measured annually in children from birth to 5 years. MRI was performed in a sub-group of 44 children at 5 years to estimate abdominal fat.

Results: Almost half of the women (n = 86/186) gained excess weight in pregnancy, and women with a BMI ≥ 25 kg/m² (n = 33) were more likely to gain in excess. Mid-pregnancy GWG predicted higher weight (g) and subcutaneous fat by ultrasound (mm²) and MRI (cm³) at 5 years [β: 139.34 g (95% CI: -0.22; 278.90), p = 0.050; β: 1.42 mm² (95% CI: 0.06; 2.78), p = 0.041; and β: 18.56 cm³ (95% CI: 1.30; 35.82) p = 0.036, respectively].

Conclusions: Mid-pregnancy weight gain was associated with greater fat depots at 5 years, which suggests that the timing of GWG has differential effects on offspring adiposity outcomes.

Impact: Gestational weight gained in mid-pregnancy is associated with growth and adipose tissue development at 5 years. We observed that maternal weight gain in early and mid-gestation has differential effects on offspring body composition. Mid-pregnancy weight gain (15-32 weeks gestation) appears to influence child growth and abdominal fat accretion which may have implications for long-term metabolic health. Interventions that prevent excessive gestational weight gain in mid-pregnancy may affect obesity risk in early childhood. Prenatal care should stress the importance of optimal weight gain throughout pregnancy.