Clinical decision-support tool. All calculations are performed locally in your browser. No patient data is transmitted or stored. For clinical decisions, interpret in the context of image quality, serial data and the full echocardiographic examination. Reference range: Zidere V et al., J Am Soc Echocardiogr 2021 (validated 13–36 weeks).
Biometry
Gestational age is required for all Z-scores. Valid range: 13–36 weeks.
Outflow tract peak velocities
Pulsed-wave Doppler, cm/s. Measure at valve level; angle-correct to <20°.
Left inflow — mitral valve
E-wave and A-wave in cm/s; E/A ratio (computed or entered directly).
Fetal inflow is A-wave dominant (E/A < 1) throughout gestation — opposite to the adult heart. E/A approaching 1 is abnormal and warrants investigation.
Right inflow — tricuspid valve
E-wave and A-wave in cm/s; E/A ratio (computed or entered directly).
Same principle as the mitral valve — E/A is normally < 1. Tricuspid E/A approaching 1 may indicate RV diastolic dysfunction or volume load.
Fetal heart rate
Average rate in bpm from M-mode or Doppler.
Live findings
Enter measurements above — abnormal and borderline results will appear here.
Reference
Zidere V, Vigneswaran TV, Allan LD, Simpson JM. Doppler velocities across fetal cardiac valves and the relationship to fetal heart rate: a prospective study. J Am Soc Echocardiogr 2021; 34(11): 1169–1179.e2. doi:10.1016/j.echo.2021.05.011.