Background: Prenatal echocardiography has shown evidence of prenatal development of congenital heart disease. Prenatal cardiac anatomy, chamber size and function change during gestation, so that the appearance of cardiac structure in abnormal hearts may be different from that which is usually seen postnatally.
Methods: Published prenatal echocardiographic studies were reviewed and in utero development of congenital heart disease from midtrimester to the early postnatal period is discussed.
Results: The growth of the great vessels and ventricles is reduced in fetuses with ventricular outflow obstruction. Valve regurgitation may progress. The foramen ovale and ductus arteriosus have been reported to become restrictive in utero in several settings. Pulmonary vascular obstructive changes may progress prenatally. Fetal arrhythmia (both bradycardia and tachycardia) may develop in utero. Development of congestive heart failure is a very important issue during follow up of fetuses with significant cardiac or extracardiac problems. Some may progress to fetal hydrops and prognosis of the affected fetuses is usually very poor.
Conclusions: Correct knowledge of possible development is important for accurate prenatal diagnosis. Information on prenatal progression of the cardiac anomaly is also important to make plans for follow up and perinatal management, to predict outcomes and to counsel family. Furthermore, the benefits of prenatal treatment instead of postnatal treatment should be assessed by the accurate prediction of the progression of the cardiac problem in utero. Further extensive studies using a large number of cases is required to predict progression accurately. In addition, further studies for elucidating the mechanisms of progression is important to provide better outcomes for fetuses with various congenital heart diseases.