Masked pregnancy-associated hypertension as a predictor of adverse outcomes

Am J Obstet Gynecol MFM. 2023 Jul;5(7):100976. doi: 10.1016/j.ajogmf.2023.100976. Epub 2023 Apr 23.


Background: 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.

Objective: 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.

Study design: 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.

Results: 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.

Conclusion: 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.

Keywords: digital medicine; home blood pressure monitoring; hypertensive disorders of pregnancy; masked hypertension.

MeSH terms

  • Female
  • Hospitalization
  • Humans
  • Hypertension, Pregnancy-Induced* / diagnosis
  • Hypertension, Pregnancy-Induced* / epidemiology
  • Infant, Newborn
  • Masked Hypertension* / diagnosis
  • Masked Hypertension* / epidemiology
  • Pre-Eclampsia*
  • Pregnancy
  • Retrospective Studies