Ultrasound systems and methods provide a workflow to automatically identify a fetal heartbeat. A region of interest (ROI) is identified in an ultrasound image and an ROI is identified that contains the fetal heart. The ultrasound system produces spatially different M-mode lines associated with the ROI. The ultrasound system can identify a fetal heartbeat by tracking the changing position of the heart wall and estimate the fetal heart rate, e.g. by measuring from peak-to-peak of two subsequent waves. The echo signals for the M-mode lines can also be ranked according to the likely presence of a fetal heartbeat in the echo data.