Determining the risk of gestational hypertension, preeclampsia, and adverse perinatal outcomes in patients with antenatal lower threshold blood pressure elevations: A retrospective cohort study / Philippine Journal of Obstetrics and Gynecology

ABSTRACT

Background@#Diagnosing hypertensive disorders in pregnancy utilizes systolic blood pressure (BP) of >140 mmHg and/or diastolic of >90 mmHg. However, since 2017, the American College of Cardiology and the American Heart Association (ACC/AHA) have been endorsing lower BP thresholds for diagnosing hypertension.@*Objectives@#This study determines if antenatal lower threshold BP elevations under elevated BP and Stage 1 hypertension from ACC/AHA show an increased risk of gestational hypertension, preeclampsia, and adverse perinatal outcomes.@*Materials and Methods@#This retrospective cohort study included service patients with prenatal consultations and deliveries at a private tertiary-level hospital from February 2016 to 2020. Antenatal BP measurements, categorized into “normal,” “elevated BP,” and “Stage 1 hypertension” under ACC/AHA classifications, had crude and adjusted relative risks (aRRs) and 95% confidence intervals (CIs) estimated to determine their associations with hypertensive disorders of pregnancy.@*Results@#Stage 1 hypertension was twice more likely to develop gestational hypertension (aRR 2.314, 95% CI 1.08–4.98) and thrice more likely to develop preeclampsia (aRR 3.673, 95% CI 2.30–5.86), whether without (aRR 3.520, 95% CI 1.33–9.29) or with severe features (aRR 3.717, 95% CI 2.16–6.41). There was a slightly increased risk for adverse perinatal outcomes from Stage 1 hypertension, as well as all outcomes from elevated BP, but was not statistically significant. Majority of BP elevations were during the third trimester.@*Conclusion@#Lower threshold Stage 1 hypertension showed an increased risk of developing hypertensive disorders of pregnancy, with a three-fold increased risk for preeclampsia. There may be advantages in its application for diagnosing preeclampsia or having increased monitoring for these patients.