Early prenatal diagnosis of major congenital heart defects

Specialized fetal echocardiography at 18 to 22 weeks for highrisk groups is well established as being sensitive and specific for most cardiac abnormal ities. Early fetal echocardiography ( < 16(+0) weeks, i.e. 16 weeks and 0 d ays) is a feasible alternative to mid second trimester scanning for familie s at risk of congenital heart disease. Two main areas have contributed to t he increasing interest in first and early second trimester fetal echo. The recognition of the association between increased nuchal translucency and st ructural heart abnormalities has led to the identification of an important high-risk group at 11 to 14 weeks. Furthermore, the use of modern ultrasoun d technology has allowed greater utilization of transabdominal scanning in addition to the transvaginal route. Most major structural heart defects can accurately be diagnosed from the late first trimester of pregnancy and man y families at-risk can be reassured of 'normality' of cardiac connections a t an early stage. Some lesions may evolve throughout pregnancy and therefor e early scans should not replace mid trimester fetal echocardiography. Curr Opin Obstet Gynecol 13:155-159. (C) 2001 Lippincott Williams & Wilkins.