SMFM Statement: Antihypertensive therapy for mild chronic hypertension in pregnancy: The CHAP Trial

Chronic hypertension occurs in approximately 2% of pregnancies in the United States and remains a major cause of maternal and perinatal morbidity and mortality. Specifically, chronic hypertension is associated with an increased risk of preeclampsia, pulmonary edema, acute kidney injury, cardiomyopathy, stroke, medically-indicated preterm birth, placental abruption, small-for-gestational-age (SGA) newborns, maternal mortality, and perinatal deaths. While there is a consensus supporting the treatment of severe chronic hypertension in pregnancy to mitigate these risks, significant variation in international guidelines exists regarding the treatment of mild chronic hypertension (defined as systolic blood pressure [BP] ≥140 mm Hg and <160 mm Hg or diastolic BP ≥90 mm Hg and <110 mm Hg or both). The purpose of this document is to review the results of the recently published Chronic Hypertension and Pregnancy (CHAP) randomized controlled trial and provide guidance for the implementation of the study findings.

Access the ACOG Practice Advisory on the CHAP study.

Key words: antihypertensive therapy, Chronic Hypertension and Pregnancy (CHAP) trial