Maternal Outcomes Associated With Lower Range Stage 1 Hypertension

Abstract

Objective: To evaluate maternal and neonatal outcomes in healthy, nulliparous women classified with stage 1 hypertension under the revised American College of Cardiology and American Heart Association Guidelines and to evaluate the effects of low-dose aspirin on maternal and neonatal outcomes in this population.

Methods: We conducted a secondary analysis of data from a multicenter randomized, double-blind, placebo-controlled trial of low-dose aspirin for prevention of preeclampsia in nulliparous, low-risk women recruited between 13 and 25 weeks of gestation. Of the 3,134 nulliparous women enrolled in the original study, 2,947 women with singleton pregnancies and without missing data were included in this analysis. Blood pressure was measured at enrollment between 13 and 25 weeks of gestation and outcomes were adjudicated from the medical record.

Results: One hundred sixty-four participants were identified with lower range stage 1 hypertension (5.6%), systolic blood pressure 130-135 mm Hg, diastolic blood pressure 80-85 mm Hg, or both by the new American College of Cardiology-American Heart Association guidelines. Within the placebo group (n=1,482), women with stage 1 hypertension had a significantly increased incidence of preeclampsia compared with normotensive women, 15.3% (15/98) vs 5.4% (75/1,384) (relative risk 2.66, 95% CI 1.56-4.54, P<.001). Moreover, women with stage 1 hypertension had an increased incidence of gestational diabetes mellitus (6.1% vs 2.5%, P=.03) and more indicated preterm deliveries (4.2% vs 1.1%, P=.01). Comparing women with stage 1 hypertension and normotensive women receiving low-dose aspirin during pregnancy (n=1,465), no differences in rates of preeclampsia (7.6% vs 4.4%, respectively, P=.2), gestational diabetes mellitus, or indicated preterm deliveries were observed. Rates of placenta abruption, small for gestational age, and spontaneous preterm birth did not differ significantly between groups.

Conclusion: Application of the new American College of Cardiology-American Heart Association guidelines in a pregnant population identifies a cohort of women who are at increased risk for preeclampsia, gestational diabetes mellitus, and preterm birth.