Should ACOG Reconsider Their Criteria for the Early Diagnosis of Hypertension in Pregnancy?

Background
In 2017, the American College of Cardiology (ACC) and the American Heart Association (AHA) released new guidelines for the evaluation of high blood pressure (BP). These lowered definitions for hypertension include: normal (<120/80 mmHg), elevated (120-129/<80 mmHg), stage 1 (130-139/80-89 mmHg), and stage 2 hypertension (≥140/90). Conversely, ACOG defines chronic hypertension as the presence of systolic BP≥140 mmHg or diastolic BP≥90 mmHg on ≥2 occasions before 20 weeks’ gestation.

There is limited data on the impact of hypertension as defined by the ACC/AHA in pregnancy. We aim to determine if there is a relationship between elevated or stage 1 hypertension in the first trimester and pregnancy-induced hypertensive disorders (PIH).

Methods
In this IRB approved retrospective cohort study, we examined singleton pregnancies, registered in the first trimester and diagnosed with PIH (gestational hypertension, preeclampsia +/- severe features, and HELLP) at an urban hospital between March and September 2018.

Results
110 patients were included: 61.8% of the study population had elevated (22.7%) or stage 1 (39.1%) hypertension. The mean age was greater in normotensive patients(p=0.03). Otherwise, demographics, gestational age(p=0.27), and timing of delivery(p=0.41) were similar between hypertension groups. Neither the incidence of PIH nor the specific PIH diagnosis were associated with hypertension status in the first trimester(p=0.08).

Conclusions
Our data suggests no association between ACC/AHA hypertension status in the first trimester and PIH. However, over 60% of patients would be classified as early/stage I hypertension. Therefore, further evaluation of the incidence of ACC/AHA hypertension in patients with/without PIH and comparison to ACOG criteria is warranted.