Masked pregnancy-associated hypertension as a predictor of adverse outcomes

Masked hypertension has been described in nonpregnant populations as elevated blood pressure in the home setting that is not reproduced on clinical assessment. Patients with masked hypertension have a greater risk of cardiovascular morbidity than patients who have blood pressures within normal range or those with white coat hypertension.

This study aimed to determine whether masked pregnancy-associated hypertension detected on Connected Maternity Online Monitoring, a remote home blood pressure monitoring system, is associated with higher rates of hypertensive disorders of pregnancy during delivery admission and maternal and neonatal morbidities.

This was a retrospective cohort study of all patients on Connected Maternity Online Monitoring who delivered at 6 hospitals in a single healthcare system between October 2016 and December 2020. Patients were classified as having either normal blood pressure or masked pregnancy-associated hypertension. Masked pregnancy-associated hypertension was defined as remotely detected systolic blood pressure of ≥140 mm Hg or diastolic blood pressure of ≥90 mm Hg after 20 weeks of gestation on 2 occasions before diagnosis in a clinical setting. The chi-square test and Student t test were used for demographic and outcomes comparisons. Logistic regression was used to adjust outcomes by race, insurance, and body mass index.

A total of 2430 deliveries were included in our analysis, including 165 deliveries that met the criteria for masked pregnancy-associated hypertension. Clinically established pregnancy-associated hypertension, defined at the time of delivery, was more common in the masked pregnancy-associated hypertension group than in the normotensive group (66% vs 10%; adjusted odds ratio, 17.2; 95% confidence interval, 11.91-24.81). Patients with masked pregnancy-associated hypertension had higher rates of preeclampsia with severe features on delivery admission than normotensive patients (28% vs 2%; adjusted odds ratio, 23.35; 95% confidence interval, 14.25-38.26). Preterm delivery (16% vs 7%; adjusted odds ratio, 2.47; 95% confidence interval, 1.55-3.94), cesarean delivery(38% vs 26%; adjusted odds ratio, 1.58; 95% confidence interval, 1.13-2.23), small for gestational age (11% vs 5%; adjusted odds ratio, 2.27; 95% confidence interval, 1.31-3.94), and neonatal intensive care unit admission (8% vs 4%; adjusted odds ratio, 2.20; 95% confidence interval, 1.18-4.09) were more common among patients with masked pregnancy-associated hypertension than among normotensive patients.

With more outcomes research, remote blood pressure monitoring may prove to be an important tool in identifying pregnancies at risk of complications related to masked hypertension.