Stage 1 Hypertension in Pregnancy and Risk for Severe Maternal Morbidity

Stage 1 Hypertension, characterized as systolic blood pressure (SBP) 130-139 or diastolic blood pressure (DBP) 80-89 is a well-defined pathology in the non-obstetric population; however, it is currently not recognized as a hypertensive diagnosis in the setting of pregnancy. Given the increased risk of adverse pregnancy outcomes due to hypertension in pregnancy, we sought to determine if patients who met diagnostic criteria for stage 1 hypertension were at increased risk for severe maternal morbidity. This was a retrospective cohort study of patients who initiated prenatal care prior to 20 weeks gestation and delivered within a single healthcare system from October 2016 to December 2020. Patients with ACOG-defined chronic hypertension or higher order multiple gestation were excluded. Sustained clinical SBP >130 or DBP >80 prior to 20 weeks classified stage 1 hypertension, and outcomes were compared by presence of stage 1 hypertension. All patients were managed as normotensive according to current ACOG guidelines. Primary outcome was severe maternal morbidity (SMM) as defined by the CDC. Secondary outcomes included preeclampsia, cesarean delivery, preterm delivery, small for gestational age, neonatal intensive care and perinatal death. Among 19,862 included deliveries, 2,596 deliveries (13%) met diagnostic criteria for stage 1 hypertension. Patients with stage 1 hypertension were more likely to be black, obese, nulliparous and use public insurance (Table 1). SMM was similar between groups when adjusting for age, BMI, insurance and twin gestation (3.9% vs. 3.0%, aOR 1.26, 95% CI 0.97-1.63). Preeclampsia was increased in the stage 1 hypertension group (aOR 2.73, 95% CI 2.31, 3.23), as were several adverse perinatal outcomes (Table 2). Stage 1 Hypertension diagnosed in the first half of pregnancy is not associated with SMM. Risk for preeclampsia, preterm delivery and adverse perinatal outcomes is increased.View Large Image Figure ViewerDownload Hi-res image Download (PPT)