Pregnancy outcomes in women with heart disease: the Madras Medical College Pregnancy And Cardiac (M-PAC) Registry from India

To evaluate the feto-maternal outcome, identify the adverse outcome predictors and test the applicability of modified WHO (mWHO) classification in pregnant women with heart disease (PWWHD) from Tamil Nadu, India.

One thousand and five pregnant women (mean age: 26.04 ± 4.2) with 1029 consecutive pregnancies were prospectively enrolled from July 2016 to December 2019 in the Madras medical college pregnancy and cardiac (M-PAC) registry. Majority (60.5%; 623/1029) had heart disease (HD) diagnosed for the first time during pregnancy. Rheumatic HD (42%; 433/1029) was most common. One third (34.2%; 352/1029) had pulmonary hypertension (PH). Maternal mortality and composite maternal cardiac events (MCEs) were the primary outcomes. Secondary outcomes were foetal loss and composite adverse foetal events (AFEs). MCEs occurred in 15.2% (156/1029; 95% CI: 13.0–17.5) pregnancies. Heart failure was the most common MCE (66.0%; 103/156; 95% CI: 58.0–73.4). Maternal mortality was 1.9% (20/1029; 95% CI: 1.1–2.8), with highest rates in patients with prosthetic heart valves (PHVs) (8.6%; 6/70). Left ventricular systolic dysfunction (LVSD), PHVs, severe mitral stenosis, PH and current pregnancy diagnosis of HD were independent predictors of MCE. The c-statistic of mWHO classification for predicting MCE and maternal death were 0.794 (95% CI: 0.763–0.826) and 0.796 (95% CI: 0.732–0.860). 91.2% (938/1029; 95% CI: 89.392.8) of pregnancies resulted in live births. 33.7% (347/1029; 95% CI: 30.8–36.7) of pregnancies reported AFEs.

Maternal mortality is high in PWWHD from India. Highest death rates occurred in women with PHVs, PH and LVSD. The mWHO classification for risk stratification may require further adaptation and validation in India.