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

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 patients with PH may be lower than previously reported. 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 classification. Primary end points include maternal mortality and 30-day nonelective readmission rate. Other adverse short-term maternal (cardiovascular and obstetric) and fetal outcomes were also analyzed. Of 9,922,142 pregnant women, 3,532 (0.04%) had 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 in the World Health Organization PH groups. Patients with PH had a significantly higher nonelective 30-day readmission rate (10.4% vs 2.3%) and maternal adverse obstetric events (24.2% vs 9.1%) compared with those without PH (p <0.001) (Figure 1). In conclusion, pregnant women with PH had significantly higher adverse event rates, including in-hospital maternal mortality (85-fold), compared with those without PH.