PREVALENCE OF CHRONIC HYPERTENSION IN PREGNANT WOMEN FOLLOWING THE 2017 ACC/AHA GUIDELINE CHANGE IN DIAGNOSTIC CRITERIA FOR HYPERTENSION

Abstract

Objective: To examine the effect of the 2017 American College of Cardiology/American Heart Association (ACC/AHA) guideline for high blood pressure (BP) on the prevalence of chronic hypertension in pregnant women. Design and method: We conducted a cross-sectional study among women aged 15–49 years who had a live or stillbirth between 2009 and 2014 within an integrated US healthcare system. We compared the prevalence of chronic hypertension by the 2017 ACC/AHA guideline (defined as BP > = 130/80 mmHg) and the American College of Obstetricians and Gynecologists (ACOG) guideline (defined as BP > = 140/90 mmHg) overall and stratified by maternal age at delivery and race/ethnicity. Chronic hypertension was defined as > = 2 high BPs from outpatient encounters on different days within 30 days and taken < = 20 weeks gestation. The lowest BP value was used when there were multiple measurements from a single encounter. Women dispensed antihypertensive medication and who had a diagnosis of hypertension were classified as having hypertension by both guidelines regardless of BP value. Results: A total of 143,191 unique pregnancies were included (mean age was 30.1 years; 51% Hispanic, 26% non-Hispanic White, 8% non-Hispanic Black, 13% Asian). The prevalence of hypertension by ACOG and AHA/ACC was 2.3% and 9.7%, respectively. Using the 2017 ACC/AHA guideline, we identified 108,512 (75.8%) women with normal BP (<120/80 mmHg), 20,808 (14.5%) women with elevated BP (120–129/< 80 mmHg), 12,658 (8.8%) with hypertension stage 1 (130–139/80–89 mmHg), and 1,213 (0.9%) with hypertension stage 2 (> = 140/90 mmHg). Using ACOG criteria, 139,937 (97.7%) women had BP < 140/90 mmHg (31,425 of these women (22.5%) had BP 120–139/80–89 mmHg) and 3,254 (2.3%) women had hypertension (27 of these women (0.8%) had severe hypertension defined as BP> = 160/110 mmHg). Younger women and non-Hispanic whites and Hispanics experienced larger increases in the prevalence of hypertension by the 2017 ACC/AHA guideline (Figure). Conclusions: Adoption of the 2017 ACC/AHA guideline to define hypertension increased the prevalence of chronic hypertension in pregnancy over 300%. Further research is needed to examine whether this lower threshold for defining hypertension in pregnancy is associated with increased maternal and neonatal complications.