CRL using Smith et al formula REFERENCES UK date system ie date/month/year (4 digits for year)
Normal range for Z score is -1.645 to +1.645. If only two growth measurements
are available, please put the scan details in the second and third scan boxes.
This calculator is for educational use. It is believed accurate but no
responsibility for accuracy of the results is accepted by the author. David J R
Hutchon BSc, MB, ChB, FRCOG Consultant Obstetrician, Memorial Hospital,