Maternal Cortisol During Pregnancy and Infant Adiposity: A Prospective Investigation

Context Glucocorticoids play a key role during intrauterine development in cellular growth and differentiation. Evidence suggests that exposure to inappropriate concentrations of glucocorticoids during sensitive developmental periods may produce alterations in physiological systems that impact obesity risk. Objective To elucidate the magnitude and stage-of-gestation-specific association of maternal cortisol concentrations during pregnancy with infant adiposity. Design, Participants, and Setting Sixty-seven mother-child dyads recruited in early pregnancy at university-based obstetric clinics in Southern California were followed with serial assessments from early gestation through birth until 6 months postnatal age. Maternal cumulative cortisol production was assessed over each of 4 consecutive days in early (≅13 weeks), mid (≅24 weeks), and late pregnancy (≅30 weeks) (5 saliva samples/d × 4 days × 3 trimesters = 60 saliva samples/subject). Infant body composition was serially assessed in newborns (at ∼25 days postnatal age) and at ∼6 months age with dual-energy X-ray absorptiometry imaging. Results After adjusting for key prenatal, birth, and postnatal covariates, higher maternal cortisol during the early third trimester (conditioned on prior early and midgestation cortisol concentrations) was significantly associated with a greater change in infant percent body fat from 1 to 6 months of age [partial r (adjusted for covariates) = 0.379, P = 0.007], accounting for ∼14% of the variance in this measure of childhood obesity risk. Conclusion The present findings suggest a stage-of-gestation-specific effect of maternal cortisol on infant adiposity gain in early postnatal life and provide evidence in humans to support the role of glucocorticoids in fetal programming of childhood obesity risk.