An ultrasound system and method provide a workflow to acquire 3D images of the fetal heart gated by a synthetic heart gating signal. An ROI is defined in an ultrasound image which delineates the fetal heart. The ultrasound system is controlled to automatically estimate the fetal heart rate from echo signals received from the ROI. When the system has acquired a stable synthetic heart rate signal an indication thereof is given to the user and the user then commands the system to acquire 3D fetal heart images for a number of fetal heart cycles which are gated using the synthetic heart rate signal. Fig.1
