Risk of Hypertensive Disorders of Pregnancy in Patients With Cardiac Disease.

Background: Pregnant patients with cardiovascular disease (CVD) face increased risk of preeclampsia and preterm delivery, yet data is limited data regarding degree of risk and impact of hypertensive disorders of pregnancy (HDP) on gestational age at delivery.

Objectives: To examine HDP risk and impact on delivery timing in patients with CVD.

Methods: This retrospective cohort study included patients >18 years old who delivered between 10/1/2015 and 12/31/2020 using the Premier Healthcare Database. Patients with CVD were divided into six categories: congenital, ischemic, aortic pathology, pulmonary hypertension, cardiomyopathy, and valvular disease. The primary outcome was risk of HDP (gestational hypertension/ preeclampsia). The secondary outcome was gestational age at delivery. Multivariable mixed effects regression models were used to estimate adjusted outcomes, adjusting for CVD subtype, >1 CVD subtype present, demographics, hospital characteristics, and comorbidities.

Results: Among 4,606,247 obstetric patients, 20,021 had CVD. The risk of HDP among people with CVD varied by CVD subtype, lowest in those with congenital heart disease (aOR,0.9; 95% CI [0.8, 1.0]) and highest in those with pulmonary hypertension (aOR, 1.5; 95% CI [1.3, 1.8]) and cardiomyopathy (aOR,1.5; 95% CI [1.4,1.6]). Patients with CVD delivered earlier than those without CVD, even in the absence of HDP(36.4-38.0 weeks versus 38.4 weeks). Among those with HDP, patients with severe pre-eclampsia with CVD, delivered earlier than those without CVD (33.1-34.6 weeks versus 35.5 weeks).

Conclusion: Risk of HDP and preterm delivery is higher those with CVD, particularly in pulmonary hypertension and cardiomyopathy. Patients with CVD should be advised of their increased risk.