Pregnancy Outcomes in Women with a History of Myocarditis.

BACKGROUND: Myocarditis is an inflammatory cardiomyopathy with broad clinical spectrum. Pregnancy outcomes in women with a history of myocarditis are not well described. PURPOSE: The aim of this study is to determine maternal and fetal outcomes in pregnant women with history of myocarditis/perimyocarditis. METHODS: This was a retrospective study of pregnancy outcomes in patients with prior history of myocarditis/perimyocarditis followed in a CardioObstetrics Program (1998-2025). Adverse maternal cardiac outcomes included: maternal death, heart failure, and sustained arrhythmia. Echocardiographic changes during pregnancy were examined. Fetal adverse events: fetal death, prematurity, small for gestational age (<10th percentile). RESULTS: Thirty-six pregnancies in women (n=27) with a history of myocarditis were included [mean age 33±4.9 years, median interval between myocarditis and pregnancy 5.0 years]. In 50% of cases, there was moderate/severe left ventricular (LV) systolic dysfunction at time of myocarditis presentation. In most (83%,15/18) pregnancies, with significant LV dysfunction at time of myocarditis presentation, there was full recovery of LV systolic function prior to pregnancy. No adverse maternal cardiac events were reported in 97% (35/36) of pregnancies. One patient with moderately reduced LV systolic function during myocarditis, with recovery prior to pregnancy, developed heart failure. Two patients had reduction in LV systolic function in pregnancy, from mild/normal to moderate/severely reduced. There were no maternal or fetal deaths. Thirteen percent of pregnancies had premature delivery (31-36 weeks). CONCLUSION: Most women with prior myocarditis do not develop adverse cardiac events. However, echocardiographic surveillance during pregnancy may still be helpful to identify decreases in LV systolic function.