Objective: To evaluate both short and mid-term effects of maternal COVID-19 on cardiac functions of fetuses and children. Methods: The present case-control study was conducted on 36 pregnant women who had COVID-19 infection in the second trimester of pregnancy and 30 pregnant women as healthy controls. Fetal, neonatal and infant cardiac functions were compared between the groups. Assessment of fetal cardiac functions were performed in the last trimester of the pregnancy at least 6 weeks after the recovery of infection. The first postnatal echo was performed within the first two weeks and the follow-up (second) echo was performed in the 6-8 weeks of life. Results: The demografic data were similar between groups. Interventricular septum and left ventricular posterior wall end-diastolic dimensions were significantly higher in the study group in both fetal, neonatal and infant periods. Impaired diastolic functions of right and left ventricles were detected and myocardial performance indexes with tissue doppler imaging of both lateral walls and septum were significantly higher than controls at all periods. Conclusion: Maternal COVID-19 seems to have a global impact on cardiac functions of babies in the short and mid-term periods after maternal recovery.