Perceived Stress During Late Pregnancy and Infant Body Composition at 1 Month.

Context: Worldwide, obesity remains one of the most challenging crises with children being one of the most susceptible populations. The effect of maternal stress during pregnancy on newborn body composition, measured by fat mass and lean mass has, not been extensively studied.

Objectives: We evaluated the association between perceived stress during late pregnancy and infant adiposity at 1 month and assessed effect modification by infant sex and preterm birth.

Methods: Mother-infant dyads (N = 138) were included from the ongoing MADRES cohort. Maternal perceived stress during late pregnancy was measured by the 10-item Perceived Stress Scale (PSS), as a cumulative score, during the third trimester. Infant adiposity measures, collected at 1 month by EchoMRI, included weight, fat mass (FM), and lean mass with FM-related ratios derived. Multivariable linear regression models with interaction terms were performed.

Results: Most mothers reported low to moderate stress (mean ± SD PSS: 13.2 ± 5.6) during late pregnancy. A 1-SD higher PSS was associated with higher FM% (FM (g)/weight (g): β = 0.78%; 95% CI, 0.13-1.44) but we did not find significant associations for the other adiposity measures. Statistically significant effects of perceived stress on FM-related measures were observed in male infants and preterm infants (both P for interaction <.05) but were null among female infants or term infants.

Conclusion: In this predominately low-income Hispanic population, perceived stress during late pregnancy was associated with higher FM-related body composition measures during early infancy; this association was stronger among male and preterm infants compared to the overall population and other subgroups.