Cardiac and obstetric outcomes in pregnant patients with heart disease: a retrospective cohort study

Cardiac diseases complicate 4% of pregnancies, with a mortality rate between 0 and 15%. Early referral has shown to reduce the risk of maternal major cardiac events (MACEs).

We retrospectively analyzed a cohort of pregnant women with heart disease from two referral centers in Mexico City. We examined MACEs: maternal death, pulmonary edema, acute heart failure, endocarditis, stroke, myocardial infarction, acute aortic syndromes, arrhythmias requiring urgent treatment, and the need for an urgent intervention; preterm birth and obstetric events such as HELLP syndrome, preeclampsia, eclampsia, placental abruption, obstetric hemorrhage. We analyzed the association between each modified World Health Organization (mWHO) group and MACEs, preterm birth and obstetric outcomes between March 2014 and March 2019.

Using the mWHO classification, 399 deliveries were included and stratified as follows: I, 162; II, 133; II-III, 21; III, 18; and IV, 52 patients. MACEs were observed in 12.5% of the cohort and were associated with mWHO II (odds ratio [OR], 3.0; 95% confidence interval [95% CI], 1.1-8.1; p = 0.027), II-III (OR, 3.3; 95% CI, 0.9-1.0; p = 0.116), III (OR, 5.3; 95% CI, 1.2-23; p = 0.026), and IV (OR, 8.2; 95% CI, 2.7-24.5; p < 0.001) after adjusting for age, desaturation, previous functional class, and gestational age at referral. An association between mWHO and frequency of preterm birth was observed. Association between mWHO and obstetric events, even when adjusted, was not observed.

The prevalence of MACEs and preterm birth is similar to that seen worldwide; MACEs and preterm birth are associated with the severity of heart disease stratified by mWHO, but there is no association between the severity of heart disease and obstetric events.