Maternal Morbidity According to Mode of Delivery Among Pregnant Patients With Pulmonary Hypertension.

BACKGROUND: Patients with pulmonary hypertension have a high risk of maternal morbidity and mortality. It is unknown if a trial of labor carries a lower risk of morbidity in these patients compared to a planned cesarean delivery. The objective of this study was to examine the association of delivery mode with severe maternal morbidity events during delivery hospitalization among patients with pulmonary hypertension. METHODS: This retrospective cohort study used the Premier inpatient administrative database. Patients delivering ≥25 weeks gestation from January 1, 2016, to September 30, 2020, and with pulmonary hypertension were included. The primary analysis compared intended vaginal delivery (ie, trial of labor) to intended cesarean delivery (intention to treat analysis). A sensitivity analysis was conducted comparing vaginal delivery to cesarean delivery (as treated analysis). The primary outcome was nontransfusion severe maternal morbidity during the delivery hospitalization. Secondary outcomes included blood transfusion (4 or more units) and readmission to the delivery hospital within 90 days from discharge from delivery hospitalization. RESULTS: The cohort consisted of 727 deliveries. In the primary analysis, there was no difference in nontransfusion morbidity between intended vaginal delivery and intended cesarean delivery groups (adjusted odds ratio [aOR], 0.75; 95% confidence interval [CI], 0.49-1.15). In secondary analyses, intended cesarean delivery was not associated with blood transfusion (aOR, 0.71; 95% CI, 0.34-1.50) or readmission within 90 days (aOR, 0.60; 95% CI, 0.32-1.14). In the sensitivity analysis, cesarean delivery was associated with a 3-fold higher risk of nontransfusion morbidity compared to vaginal delivery (aOR, 2.64; 95% CI, 1.54-3.93), a 3-fold higher risk of blood transfusion (aOR, 3.06; 95% CI, 1.17-7.99), and a 2-fold higher risk of readmission within 90 days (aOR, 2.20; 95% CI, 1.09-4.46) compared to vaginal delivery. CONCLUSIONS: Among pregnant patients with pulmonary hypertension, a trial of labor was not associated with a higher risk of morbidity compared to an intended cesarean delivery. One-third of patients who required an intrapartum cesarean delivery had a morbidity event, demonstrating the increased risk of adverse events in this group.