Objective: The 2017 American College of Cardiology/American Heart Association (ACC/AHA) guideline recommended a lower threshold (130/80 mmHg) for hypertension in nonpregnant adults. However, the influence of this guideline in Chinese pregnant women is not well characterized.
Methods: Data of 32 742 and 14 479 mothers who had blood pressure (BP) less than 130/80 mmHg and no proteinuria before 20 gestational weeks and delivered live singletons between 1 January 2014 and 30 November 2019 were extracted from Taizhou and Taicang register-based cohorts, respectively. The average measured BP in the third trimester was obtained and categorized according to the 2017 ACC/AHA guideline. The association between BP and risk of adverse birth outcomes was assessed by multivariate logistic regression analysis.
Results: In the third trimester, 331 (1.01%) and 378 (2.61%) women had mean BP at least 140/90 mmHg, but 2435 (7.44%) and 1054 (7.28%) had stage 1 hypertension (130-139/80-89 mmHg) in Taizhou and Taicang, respectively. Significant associations between stage 1 hypertension and small for gestational age [odds ratio (OR) = 1.32, 95% confidence interval (CI) = 1.14-1.52] and low birth weight (OR = 1.81, 95% CI = 1.46-2.25) were observed in the Taizhou population. Consistent results were also shown in the Taicang population [OR (95% CI), of 1.46 (1.18-1.79) and 1.50 (1.07-2.11), respectively].
Conclusion: Stage 1 hypertension in the third trimester defined by the 2017 ACC/AHA guideline was associated with an increased risk for adverse birth outcomes in Eastern Chinese pregnant women, suggesting that this guideline may improve the detection of high BP and surveillance of adverse neonatal outcomes in China.