Maternal and Fetal Health Risks Among Female Military Aviation Officers.

Military aviation poses unique occupational risks, including exposures to intermittent hypoxia, high gravitational force, and toxic materials, in addition to circadian disruption, cosmic radiation, and ergonomic stressors also present in commercial flight. We sought to investigate whether a military aviation officer's career is associated with adverse maternal or fetal health outcomes. We conducted a retrospective cohort study of female aviation and nonaviation officers in the Military Health System from October 2002 to December 2019. Exposure was identified as assignment of an aviation occupation code. Maternal and fetal health outcomes were identified by International Classification of Diseases codes from medical records. Regression analysis was used to estimate adjusted relative risks (aRR). Included in the study were 25,929 active-duty female officers, with 46,323 recorded pregnancies and 32,853 recorded deliveries; 2131 pregnancies were diagnosed in aviation officers. Pregnant aviation officers had a decreased risk of composite adverse pregnancy outcomes [aRR 0.82 (0.73-0.92)], including gestational diabetes [aRR 0.69 (0.57-0.85)] and gestational hypertension [aRR 0.84 (0.71-0.99)]. Pregnant aviation officers had a decreased risk of depression prior to delivery [aRR 0.43 (0.35-0.53)] and hyperemesis gravidarum [aRR 0.74 (0.57-0.96)], but an increased risk of placental complications [aRR 1.15 (1.02-1.30)] and fetal growth restriction [aRR 1.36 (1.16-1.60)]. Pregnant military aviation officers have an increased risk of placental complications and fetal growth restriction in spite of a lower risk of gestational diabetes and gestational hypertension. Further research is needed to determine how flight-related occupations impact pregnancy.