Methods for prenatal assessment of fetal cardiac function.

Fetal cardiac function is increasingly recognized as a marker of disease severity and prognosis in selected fetal conditions. Magnetic resonance imaging (MRI) has been used in experimental (animal) fetal cardiology but the lack of a noninvasive fetal electrocardiogram (ECG) to trigger image acquisition remains a major limiting factor precluding its application in humans. Fetal medicine specialists are therefore limited to ultrasound to evaluate human fetal cardiac function. In this review, we aim to provide a complete overview of the different ultrasound techniques that can be used for fetal cardiac function assessment and we discuss their (theoretical) strengths and shortcomings. Conventional methods include M-mode assessment of ventricular contractility and Doppler assessment of the precordial veins and cardiac output (CO). More recent techniques such as the measurement of the myocardial performance index (MPI), myocardial motion analysis with tissue Doppler, speckle tracking and three-dimensional (3D) ultrasound techniques are also discussed.