Maternal and Fetal Outcomes in Pulmonary Hypertension During Pregnancy: A Contemporary Nationwide Analysis

Background Pulmonary hypertension (PH) disproportionately affects women, presenting challenges during pregnancy. Historically, patients with PH are advised to avoid pregnancy; however, recent reports have indicated that the incidence of adverse events in pregnant females with PH may be lower than previously reported. Methods We conducted a retrospective cohort study in pregnant patients with PH using the National Readmission Database from January 1, 2016, to December 31, 2020. PH was categorized according to the World Health Organization (WHO) classification. Primary endpoints include maternal mortality and 30-day non-elective readmission rate. Other adverse short term maternal (cardiovascular and obstetric) and fetal outcomes were also analyzed. Results Among 9,922,142 pregnant women, 3,532 (0.04%) had pulmonary hypertension (PH), with Group 1 PH noted in 1,833 (51.9%), Group 2 PH in 676 (19.1%), Group 3 PH in 604 (17.1%), Group 4 PH in 23 (0.7%), Group 5 PH in 98 (2.8%), and multifactorial PH in 298 (8.4%). PH patients exhibited higher rates of adverse cardiovascular events (15.7% vs. 0.3% without PH, p < 0.001) and mortality (0.9% vs. 0.01% without PH, p < 0.001). Mixed PH and Group 2 PH had the highest prevalence of adverse cardiovascular events among WHO PH groups. Patients with PH had a significantly higher non-elective 30-day readmission rate (10.4% vs. 2.3%) and maternal adverse obstetric events (24.2% vs. 9.1%) compared to those without PH (p < 0.001) (Figure 1). Conclusion Pregnant women with PH had significantly higher adverse event rates, including in-hospital maternal mortality (85-fold), compared to those without PH.