The fetal 'heart-sparing effect' detected by the assessment of coronary blood flow: a further ominous sign of fetal compromise.

Fifteen years after its introduction in obstetrics, Doppler sonography can now be considered to be more than a useful tool in differentiating fetuses at low or high risk for adverse perinatal outcome. In compromised fetuses, it allows very reliable assessment of the actual condition of the fetus in the cascade of deterioration, enabling an optimized perinatal management. The visualization of coronary flow, as presented in this issue of the Journal, is an important part of the cascade of abnormal hemodynamic events detectable by Doppler in such compromised fetuses.