Deployment and Preterm Birth Among United States Army Soldiers

Abstract

With increasing integration of women into combat roles in the United States military, it is critical to determine whether deployment, which entails unique stressors and exposures, is associated with adverse reproductive outcomes. Few studies have examined if deployment increases the risk of preterm birth; no studies have examined a recent cohort of servicewomen. We therefore used linked medical and administrative data from the Stanford Military Data Repository for all United States Army soldiers with deliveries between 2011–2014 to estimate the associations between prior deployment, recency of deployment, posttraumatic stress disorder and spontaneous preterm birth, adjusting for socio-demographic, military-service, and health-related factors. Of 12,877 deliveries, 6.1% were spontaneous preterm births. The prevalence was doubled (11.7%) among soldiers who delivered within 6 months of return from deployment. Multivariable discrete-time logistic regression models indicated that delivering within 6 months of return from deployment was strongly associated with spontaneous preterm birth (adjusted odds ratio = 2.1, 95% confidence interval: 1.5, 2.9). Neither multiple past deployments nor posttraumatic stress disorder were significantly associated with spontaneous preterm birth. Within this cohort, timing of pregnancy in relation to deployment is identified as a novel risk factor. Increased focus on servicewomen's pregnancy timing and pre-deployment access to reproductive counseling and effective contraception is warranted.