Deployment Among Active-Duty Military Women and Pregnancy-Related Hypertensive Disorders

Introduction: Today women comprise 15% of the U.S. active-duty military, but are often overlooked in research of the Armed Forces. While some of the challenges faced by women are similar to men, they encounter unique stressors, including pregnancy-related issues. Hypertensive disorders of pregnancy (HDPs) affect 5-10% of pregnancies annually and have been linked to maternal stress, but no studies have assessed the impact of maternal military deployment on HDP incidence. Thus, the purpose of the current study was to quantify the risk of HDP among active-duty U.S. military mothers who deployed in the post-9/11/2001 era. Materials and Methods: We conducted a retrospective cohort study using a U.S. Department of Defense database comprised of all active-duty women who gave birth to their first, live-born singleton infant using Tricare from January 1, 2004 to December 31, 2008. The database included records for maternal/infant birth hospitalizations and deployment. HDP was defined with ICD-9-CM codes in the maternal birth hospitalization record. We evaluated the risk of HDP associated with several deployment measures for the cohort overall and among racial/ethnic groups: (1) deployment in general (yes vs. no); (2) timing of deployment ending prior to birth (<12 months or >= 12 months prior vs. non-deployed); and, (3) cumulative time spent deployed since 9/11/2001. We used multivariable logistic regression and reported odds-ratios (OR) and 95% confidence intervals (CI). We also explored meaningful categorization of certain continuous deployment measures associated with HDP incidence. The study was approved by the University of South Florida Institutional Review Board. Results: There were a total of 36,667 births and 13.4% of mothers experienced at least one HDP. No increased risk of HDP was observed for deployed mothers compared with non-deployed mothers in the complete cohort (OR = 1.02, 95% CI: 0.95-1.09), but cumulative deployment length >= 1 year was identified as a potential risk factor for HDP vs. <1 year deployment (OR = 1.17, 95% CI: 1.00-1.36). Conclusion: Our study was the first to quantify the incidence of HDP among activeduty military women giving birth to their first child. It was slightly higher than in the general population, but deployment overall is seemingly not responsible for the elevated incidence.