Evaluation of the Fetal Heart

The fetal heart often provides information regarding alterations in the fetal circulation that are associated with IUGR. One of the most common findings is disproportion between the right and left sides of the heart. This is the result of volume loading of the right atrium and ventricle. The reason the fetus does this is an attempt to deliver more blood to the placenta, while maintaining blood flow to the fetal brain. The first ultrasound sign of this change is dilation of the right atrium. This is followed by dilation of the right ventricle.

This is the four-chamber view of the fetal heart. The chambers are labeled as follows: LV=left ventricle,RV=right ventricle, LA=left atrium, RA=right atrium. The right atrium is dilated compared to the left atrium

This is the four-chamber view of the fetal heart. The chambers are labeled as follows: LV=left ventricle,RV=right ventricle, LA=left atrium, RA=right atrium. The right atrium is dilated compared to the left atrium. The white circles illustrate these changes.