Depression during pregnancy: is the developmental impact earlier in boys? A prospective case-control study.

Objective: Animal studies have shown sex differences in the impact of prenatal maternal stress on the offspring. The aim of this prospective case-control study was to assess the effect of prenatal depression on newborn and 1-year-old infant characteristics as related to gender, controlling for confounding variables.

Method: We screened 205 pregnant women from April 2004 to November 2006 for depressive symptoms. Inclusion in the prenatal depression group (n = 34) was based on meeting DSM-IV criteria for major depressive episode. We excluded postnatal depression from the control group (n = 79) by routine screening at 2 and 6 months. Newborn and 1-year-old infant characteristics were evaluated with the Neonatal Behavioral Assessment Scale (NBAS) and the Infant-Toddler Social and Emotional Assessment, respectively.

Results: Despite our use of numerous exclusion criteria (eg, at-risk pregnancy, preterm delivery), prenatal depression highly correlated with anxiety and stress scores. Male newborns of mothers with prenatal depression had lower scores than controls on the motor skills and regulation of states NBAS clusters (P = .03 and P = .026, respectively). At 1 year, infants of prenatally depressed mothers presented higher scores on generalized anxiety (P = .002), particularly in males (P = .009); activity/impulsivity (P = .042); and sleep problems (P = .023) than controls.

Conclusions: As in animal studies, depression during pregnancy may affect infant development in a way that is related to gender. Early gender differences observed to be associated with depression, stress, and anxiety during pregnancy may be a key to understanding the higher prevalence in males of child psychiatric disorders.