Background: Pulmonary arterial hypertension (PAH) in pregnancy is a perilous clinical situation, known historically to result in high maternal mortality. With advances in PAH therapy and specialised care, there may be more favourable pregnancy outcomes in the modern era. We sought to systematically evaluate the adverse outcomes of PAH in pregnancies in the last decade.
Methods: We searched Medline, Embase and Cochrane databases for articles describing outcomes in pregnancy cohorts published between 2008-2018. We excluded studies with less than 5 cases, and those with insufficient data on follow up or PAH therapy. Two reviewers independently screened 3658 titles and included 13 studies for analysis. Pooled incidences and percentages of maternal and perinatal outcomes were calculated.
Results: There were 272 pregnancies reported in 258 women, 217 pregnancies advanced beyond 20 weeks gestation. The mean maternal age was 28±2 years, mean pulmonary artery systolic pressure on echocardiogram was 76±19mmHg, 74% was in good functional class I and II. The aetiologies include idiopathic PAH 21% (n=46), congenital heart disease 63% (n=136), and other aetiologies 15% (n=37). Only 48% of patients received targeted PAH therapy in pregnancy, of which 17% had combination therapy. Premature births occur in 58% of pregnancies, with a mean gestation age of 34±1 weeks at delivery. Perinatal mortality was 4% (n=8); 3% stillbirths and 1% neonatal deaths. Maternal mortality rate for advanced pregnancies was 12% overall (n=26); by aetiology breakdown, it was 20% for idiopathic PAH (9/46), 11% for congenital heart disease (15/136), and 6% for other aetiology (2/32). The reported causes of death included right heart failure, cardiac arrest, PAH crises, pre-eclampsia and sepsis. The immediate post-partum period was most precarious, 61% of maternal deaths occur at 0-4 days post-partum.
Conclusions: PAH in pregnancy continues to be hazardous with high maternal mortality rate. Continued prospective studies are needed to improve outcomes.