Maternal pulmonary hypertension and cardiopulmonary outcomes during delivery hospitalization in the United States: A nationwide study from 2016–2020

Background

Maternal pulmonary hypertension can pose substantial morbidity and mortality risks, particularly during labor and delivery. Although maternal pulmonary hypertension is conventionally considered a contraindication to pregnancy, advances in the management of pH may contribute to improving outcomes.

Objectives

In this nationwide study, we aim to characterize the prevalence of maternal pulmonary hypertension in the United States and its association with adverse cardiopulmonary outcomes during delivery hospitalizations.

Study Design

In this cross-sectional cohort study, we analyzed delivery hospitalizations in the National Inpatient Sample from 2016 to 2020. The primary exposure was maternal pulmonary hypertension. The primary outcome was a composite of maternal cardiopulmonary morbidity events during the delivery hospitalization including: death, heart failure, intraoperative heart failure, pulmonary edema, cardiac arrest, myocardial infarction, ventricular fibrillation, respiratory failure, pneumonia, acute kidney injury, and cardiac conversion. Propensity score matching was used to estimate the association between maternal pulmonary hypertension and adverse cardiopulmonary outcomes, adjusting for sociodemographic variables and validated clinical comorbidities as covariates. Secondary outcomes included mechanical circulatory support utilization, length of stay, and total hospitalization costs.

Results

Among 18,161,315 delivery hospitalizations, 4,630 patients had pulmonary hypertension, yielding a maternal pulmonary hypertension prevalence of 25 per 100,000 delivery hospitalizations with a yearly trend of increasing prevalence (odds ratio = 1.06, 95 % CI 1.01 to 1.11, P = 0.028). After propensity score matching to create well-balanced groups, 4,560 patients with pulmonary hypertension were compared to 4,560 patients without pulmonary hypertension. In this confounder-adjusted analysis, the primary composite outcome of cardiopulmonary morbidity and mortality occurred in 41.1 % of the PH group compared to 14.4 % in the no PH group (adjusted odds ratio = 4.16, 95 % CI 3.32 to 5.23, P < 0.001). Additionally, patients with PH had a higher incidence of mechanical circulatory support use (adjusted odds ratio = 9.08, 95 % CI 1.14 to 71.81, P = 0.037), longer length of stay (length of stay ratio = 2.82, 95 % CI 2.74 to 2.9, P < 0.001) and higher total hospitalization costs (total cost ratio = 1.67, 95 % CI 1.52 to 1.85, P < 0.001).

Conclusions

Maternal pulmonary hypertension is increasing in prevalence and is strongly associated with adverse cardiopulmonary outcomes in the United States, with 41.1% of pH patients experiencing a composite outcome of cardiopulmonary morbidity and mortality during delivery hospitalization. Our findings emphasize the importance of caring for patients with maternal pulmonary hypertension in a multidisciplinary setting at high-acuity centers to ensure appropriate management of cardiopulmonary complications that arise during labor and delivery.