A new definition of gestational hypertension? New onset blood pressures of 130-139/80-89 mmHg after 20 weeks of gestation.

BACKGROUND Diagnostic criteria for hypertensive disorders of pregnancy have historically been based on the American Heart Association/American College of Cardiology's definition of hypertension, previously defined as a blood pressure ≥140/90 mmHg. With the recent redefinition of hypertension, blood pressures of 130-139/80-89 mmHg are now considered abnormal. OBJECTIVE We aimed to test whether new-onset blood pressure elevations of 130-139/80-89 mmHg after 20 weeks of gestation in previously normotensive women are associated with increased risk of adverse pregnancy outcomes, specifically development of hypertensive disorders of pregnancy. STUDY DESIGN We performed a retrospective cohort study from a single tertiary care center of all women who delivered singleton gestations after 20 weeks from January 1, 2014 to June 8, 2016. Normotensive patients were defined as having maximum blood pressure <130/80 mmHg prior to 20 weeks of gestation with no prior diagnosis of chronic hypertension. Patients that remained normotensive for the remainder of pregnancy were then compared to patients who developed new blood pressure elevations 130-139/80-89 mmHg after twenty weeks gestation but prior to admission for delivery. The primary outcome was development of a hypertensive disorder of pregnancy at or during delivery admission. Clinical outcomes were assessed using χ2and multivariable logistic regression. RESULTS Of the 2,090 normotensive women from our cohort who were analyzed, 1318 (63.0%) remained normotensive for their entire antenatal course prior to delivery admission and 772 (37.0%) had new-onset blood pressure elevations between 130-139/80-89 mmHg. Women with new onset blood pressure elevations between 130-139/80-89 mmHg after 20 weeks have a significantly increased risk of developing a hypertensive disorder of pregnancy at or during their delivery admission (adjusted RR 2.41, 95% CI 2.02-2.85) including an almost 3-fold increased risk for preeclampsia with severe features, even after adjusting for confounders. There were no differences in other secondary obstetric outcomes. CONCLUSION Normotensive women with newly elevated blood pressures between 130-139/80-89mmHg after 20 weeks of gestation are more likely to develop hypertensive disorders of pregnancy and preeclampsia with severe features at or during their delivery hospitalization. These more modest blood pressure elevations may be an early indicator of disease and call into question our current blood pressure threshold for diagnosis of hypertensive diseases of pregnancy.