Maternal and fetal outcomes in patients with congenital heart disease associated with pulmonary arterial hypertension in high-altitude areas: a retrospective cohort study

OBJECTIVES: Pulmonary arterial hypertension associated with congenital heart disease (CHD-PAH) increases maternal and fetal risk. This study aimed to analyze maternal and fetal outcomes in patients with CHD-PAH in high-altitude areas. METHODS: The pregnant women with CHD were analyzed retrospectively from 2012 to 2022. Pulmonary artery systolic pressure (PASP) was estimated by echocardiography. Patients were categorized into four groups: no PAH (PASP < 40 mmHg), mild (40 mmHg≤PASP < 50 mmHg), moderate (50 mmHg≤PASP < 70 mmHg) and severe PAH (PASP ≥ 70 mmHg). RESULTS: <90%, and elevated NT-proBNP levels, but a lower rate of regular prenatal checkups compared with the no PAH and mild PAH groups (P < 0.05). The severe PAH group showed significantly higher rates of low birth weight, preterm birth, and neonatal asphyxia (P < 0.001). Independent risk factors for maternal and infant complications included NYHA functional classes III-IV (OR = 6.342, 95% CI: 2.28-17.894), NT-proBNP ≥ 250 ng/L (OR = 3.148, 95% CI: 1.121-8.840), moderate PAH (OR = 6.263, 95% CI: 1.657-23.669), and severe PAH (OR = 7.125, 95% CI: 1.792-28.334), whereas higher BMI was a protective factor (OR = 0.802, 95% CI: 0.712-0.904). CONCLUSIONS: The level of PASP, NT-proBNP, and NYHA function class, BMI may be useful in risk stratification in pregnancy with CHD-PAH in high-altitude areas.