Does acute maternal stress in pregnancy affect infant health outcomes? Examination of a large cohort of infants born after the terrorist attacks of September 11, 2001

Background: Infants in utero during the terrorist attacks of September 11, 2001 may have been negatively affected by maternal stress. Studies to date have produced contradictory results.

Methods: Data for this retrospective cohort study were obtained from the Department of Defense Birth and Infant Health Registry and included up to 164,743 infants born to active-duty military families. Infants were considered exposed if they were in utero on September 11, 2001 while the referent group included infants gestating in the same period in the preceding and following year (2000 and 2002). We investigated the association of this acute stress during pregnancy with the prevalence of preterm birth, growth deficiencies in utero and in infancy, birth defects, and the male: female sex ratio of infants.

Results: In adjusted multivariable models, neither preterm birth nor growth deficiencies were significantly associated with the terrorist attacks of September 11, 2001. Examination of the relationship between acute maternal stress experienced during the first trimester of pregnancy and birth defects revealed no significant association. In addition, no difference in sex ratio was observed among infants in utero in 2001 and infants in utero in the referent population.

Conclusions: The findings from this large population based study do not support that acute maternal stress experienced in utero during September 11, 2001 resulted in negative infant health outcomes.