Military Rank as an Independent Risk Factor of the Development of Preeclampsia

The processes that contribute to the development of preeclampsia or eclampsia are not fully understood, especially within the context of military service. The United States Preventive Services Task Force (USPSTF) has identified numerous factors associated with increases in preeclampsia and eclampsia risk including sociodemographic elements and medical comorbidities. Examining preeclampsia and eclampsia within the context of the U.S. Military Health System (MHS) offers the opportunity to isolate and stratify the association between preeclampsia or eclampsia and socioeconomic status using military rank as a proxy for income level. The diagnosis, treatment, and prevention of preeclampsia and eclampsia are key for maintaining warfighter health since poor health outcomes associated with preeclampsia and eclampsia are known to persist beyond the peripartum period.

Our design involves an observational, retrospective study using de-identified data sourced from the Medical Assessment and Readiness System (MARS) at Womack Army Medical Center. We used demographic data and ICD-10 codes to identify pregnant service members between January 2011 and December 2023 with and without a preeclampsia or eclampsia diagnosis. Data was controlled by race, ethnicity, age, education level, marital status, service branch, and military rank. Differences in the means of continuous variables were determined using t-tests, while associations between categorical variables were determined using Chi-squared tests. Regression analysis was conducted to assess the effect of military rank on preeclampsia and eclampsia risk.

There were 182,900 pregnancies and 16,959 incident diagnoses of eclampsia or preeclampsia (9.3%). Incidence was higher among junior enlisted, junior officer, and junior warrant officer ranks. Compared to those in the most abundant rank (E-4), adjusted analysis demonstrated decreased odds of preeclampsia and eclampsia diagnoses among those with a rank at or above E-8 and those with a rank of O-3. Other factors associated with increased risk of preeclampsia and eclampsia include Black race, age at or above 40 years, Navy service, and a body mass index of 25 or greater. Low-dose aspirin therapy, multiple gestation, primiparity, and chronic disease were all associated with increased odds of preeclampsia or eclampsia.

Our results demonstrated several demographic and health factors associated with increased odds of preeclampsia or eclampsia. Military rank, as a proxy for income level, was not generally associated with increased odds of preeclampsia or eclampsia in a universal healthcare system.