Effect of blood pressure control in early pregnancy and clinical outcomes in African American women with chronic hypertension

Abstract

Objective: Chronic hypertension (cHTN) affects 3-5% of all pregnancies and is twice as prevalent in African American (AA) women. AA women develop more severe HTN at an earlier onset and have higher rates of adverse pregnancy outcomes. Blood pressure control during pregnancy is controversial.

Study design: This retrospective cohort included AA women with cHTN and singleton pregnancies delivering between January 2013 and December 2016. Patients were classified as not receiving antihypertensives in the first 20 weeks (Group A), on antihypertensives in the first 20 weeks but with an average BP <140/90 during pregnancy (Group B) and on antihypertensives in the first 20 weeks but with average BP during pregnancy ≥140/90 (Group C). Adverse outcomes including severe HTN and preterm delivery <35 weeks was compared between groups.

Results: Of the 198 patients included, 68 received at least one AHT before 20 weeks including 45 patients with average BP <140/90 and 23 with average BP ≥140/90 during pregnancy. The incidence of superimposed PE and preterm birth was significantly higher among women with elevated BPs on AHT (39.1% vs 8.9% vs 17.7%, p = 0.01; preterm birth 52.2%, 8.9% and 9.2%, p < 0.001 for Groups C, B and A, respectively). A significantly higher proportion of adverse neonatal outcomes were observed in Group C (78.3%) as opposed to those in Group B (53.3%) or Group A (50.0%; p = 0.04).

Conclusions: Among AA women with cHTN, use of antihypertensives prior to 20 weeks and lower antenatal BP was associated with a decreased risk of adverse maternal and neonatal outcomes.

Keywords: Adverse perinatal outcomes; African American women; Antihypertensive use; Chronic hypertension; Pregnancy.