Echocardiographic techniques for assessing normal and abnormal fetal cardiac anatomy.

Diagnostic quality images of the fetal heart in utero can be obtained as early as 18 to 20 weeks of gestation. The cardiac structures can be imaged primarily by cross-sectional echocardiography and augmented by a combination of simultaneous M-mode echocardiography and range-gated pulsed Doppler ultrasonography. Cross-sectional images from planes through the fetal heart equivalent to planes that can be obtained after birth can be generated in utero. In a study of 168 pregnancies, 10 structural cardiac abnormalities have been defined. These abnormalities and others that have been reported indicate the potential for in utero cardiac diagnosis. The recognition of structural congenital heart disease in utero has been helpful in genetic counseling, planning the method of labor and delivery and making decisions regarding termination of pregnancy and planning postnatal care. Fetal echocardiography offers the potential to change the pattern of health care delivery to those with suspected congenital heart disease.