23: Pregnancy outcomes in patients with a single elevated blood pressure prior to 20 weeks gestation

Abstract

Chronic hypertension (cHTN) is defined as BP >140/90 on two separate occasions less than 20 weeks. The 2017 ACC/AHA guidelines lowered the diagnostic criteria of hypertension to >130/80. There remains a large proportion of pregnant women with a single elevated blood pressure (BP) in the first half of pregnancy who do not meet criteria for cHTN. We sought to describe the maternal and fetal outcomes among these women. Retrospective cohort study of all deliveries at Kaiser Permanente Southern California between 2008 and 2017. Participants were divided into normotensive (all blood pressures prior to 20 weeks < 130 and < 80) versus single elevated BP (single systolic BP 130-159 or diastolic BP 80-104). Individuals were excluded with ICD hypertension coding, antihypertensive medication use, systolic >130 or diastolic BP >80 on two separate occasions, or any severe range BPs ( >160/105). Logistic regression was used to adjust for sociodemographics, BMI, pre-eclampsia history, renal or autoimmune disease, or diabetes history. Delivery information was available for 246,009 deliveries over the study period (77% normotensive, 23% single elevated BP). Rates of pre-eclampsia/eclampsia were higher in the single elevated BP group (5.6% vs 2.6%, OR 1.86 [1.77,1.95]). Preterm delivery < 34 weeks (OR 1.29), gestational diabetes (OR 1.18), and abruption (OR 1.17) were also significantly increased. There were higher rates of cesarean, failed induction, postpartum hemorrhage, and chorioamnionitis. These findings remained significant after logistic regression. Patients with a single elevated blood pressure early in pregnancy often pose a management dilemma. Our data suggest that they may still be at increased risk of negative maternal and fetal sequelae. Further studies are needed to better characterize these patients and determine if they may benefit from heightened clinical vigilance during their antepartum course.