Maternal and fetal outcomes in pregnant women with pulmonary hypertension: The impact of left heart disease

Background: Pulmonary hypertension (PH) due to left heart disease (World Health Organization (WHO) Group 2 PH) is the largest PH subgroup, however most reports of PH in pregnancy focus on patients with pulmonary arterial hypertension (WHO Group 1 PH). We evaluated pregnancy outcomes across WHO PH subgroups. Methods: We performed a retrospective single center cohort study of maternal and fetal outcomes in pregnant women with PH (2004–2018). Results: We analyzed outcomes of 70 pregnancies in 70 women with PH (30 ± 6 years-old), classified as WHO Group 1 PH (12 (17%)), Group 2 PH (45 (64%)), Group 3 PH (4 (6%)) and Group 5 PH (9 (13%)). Although no peripartum death occurred, 3 (4.3%) women with WHO Group 2 PH had late mortality (7 ± 4 months post-partum). Additionally, 33 major adverse cardiac events occurred in 26 (37%) women, preterm birth occurred in 32 (49%), and post-partum hemorrhage in 10 (14%), such that only 24 (37%) women completed a viable pregnancy free of an adverse cardiac, obstetric or fetal/neonatal event. Major adverse cardiac events were predominantly due to heart failure (24 (73%)), occurring only in WHO Groups 1 and 2 PH (3 (25%) women vs. 17 (38%), p = 0.07), and significantly associated with pre-eclampsia, left ventricular ejection fraction ≤45%, maternal diabetes, and systemic hypertension. Conclusions: WHO Group 2 PH carries similar risk for maternal cardiovascular events when compared to women with WHO Group 1 PH. Further studies evaluating maternal risk in this cohort are needed.