Prenatal maternal stress associated with potentially life threatening situations and preterm birth and low birthweight

Objective
To analyze the association between chronic stress caused by frequent exposure to life-threatening rocket attacks, and the risk of preterm birth (PTB) and delivery of low birthweight (LBW) infants.
Study Design
A retrospective cohort study. The deliveries of women residing in a town exposed to rocket attacks (Exposed Group) were compared to deliveries of women who lived in an unexposed town (Unexposed Group). Demographic and medical data were abstracted from patients' records at the medical center serving both towns. Exposure information was obtained from official local authorities. Intensity of exposure was calculated for both the preconception and pregnancy periods.

Results
The rates of PTB and LBW were higher in Exposed vs. Unexposed Groups (9.1% vs. 6.8%, P=0.004; and 7.6% vs. 5.8%, P=0.02, respectively) . After controlling for possible confounders, including marital status, maternal age, background health problems and gestational hypertension, the risk for both outcomes remained significantly higher in the Exposed Group (PTB: adj. OR= 1.3, 95% CI 1.1-1.7; LBW: adj. OR=1.3, 95%CI 1.03-1.7). Among exposed subjects, no linear association was found between these risks and the intensity of exposure either preconception or during pregnancy.

Conclusion
Chronic exposure to life-threatening events during preconception and pregnancy is associated with increased risk of PTB and LBW.