Timing of delivery and blood pressure cut-off in chronic hypertension during pregnancy: State of art and new proposals

Objective Pregnant women with chronic hypertension are recommended to deliver at 36-39(6/7) weeks. The American College of Cardiology and American Heart Association in 2017 lowered the blood pressure cut-off for stage I hypertension to 130/80 mm Hg. Methods We performed a literature review on studies comparing elective induction of labor versus expectant management in pregnant women with chronic hypertension. In addition, we reviewed fetal and maternal outcomes in pregnant women with blood pressure of 120-139/80-89 or 130-139/80-89 mm Hg. Results We found two randomized clinical trials and one retrospective observational study comparing elective delivery of pregnant women with chronic hypertension versus expectant management. The randomized trials favored expectant management and the observational study favored induction of labor. We found 15 retrospective cohort studies analyzing maternal and fetal outcomes in pregnant women with blood pressure cut-off lower than 140/90 mm Hg. There was a consistent finding of increased risk of any hypertensive disorder of pregnancy, gestational diabetes mellitus, and small-for-gestational-age neonate. Conclusion Randomized clinical trials are needed to assess the appropriate timing of delivery for women with stage I hypertension with a blood pressure cut-off of 130/80 mm Hg.