Perinatal outcomes and 2017 ACC/AHA blood pressure categories

To evaluate the association of blood pressure category < 20 weeks according to the 2017 American College of Cardiology/American Heart Association (ACC/AHA) criteria with adverse perinatal outcomes.

A retrospective cohort study of singleton deliveries between 1/2014 and 10/2017 was undertaken. Blood pressure category assigned by 2017 ACC/AHA criteria applied to blood pressures prior to 20 weeks gestation: normal (systolic < 120 and diastolic < 80), elevated blood pressure (systolic 120-129 and diastolic < 80 mmHg), stage 1 hypertension (systolic 130-139 and/or diastolic 80-89), stage 2 hypertension (prior diagnosis of chronic hypertension or systolic ≥ 140 or diastolic ≥ 90 mmHg).

The primary outcome was preeclampsia. Secondary outcomes included preterm birth and postpartum readmission. Chi-square, ANOVA and Kruskal-Wallis tests and multivariable Poisson regression were used for analysis.

Of the 6,067 eligible pregnancies, 3,855 (63.5%) had normotensive blood pressure, 1,224 (20.2%) elevated blood pressure, 624 (10.3%) stage 1 hypertension, and 364 (6.0%) stage 2 hypertension. Compared to 4.6% prevalence of preeclampsia among normotensive pregnancies, higher categories were associated with higher preeclampsia prevalence: elevated blood pressure (10.7%, adjusted relative risk (aRR) 2.2, 95% confidence interval (CI) 1.8-2.6), stage 1 hypertension (15.1%, aRR 2.7, 95% CI 2.2-3.4) and stage 2 hypertension (38.7%, aRR 6.2, 95% CI 5.1-7.4). Non-normal categories were also associated with a higher risk of preterm birth and postpartum readmission.

Patients with elevated blood pressure and stage 1 and 2 hypertension at < 20 weeks are at increased risk of adverse obstetric perinatal outcomes.