Table 1.

Correlation (Pearson's correlation coefficient) between gestational age and spinal/conventional biometric measurements, as well as between standard biometry and spinal values. HC, head circumference; AC, abdominal circumference; FL, femur length; L a, area of the spinal canal; L v, volume of the spinal canal; LL, lumbar length; GA, gestational age

	HC	AC	FL	L1 a	L1 v	L3 a	L3 v	L5 a	L5 v	LL
GA	0.973	0.978	0.981	0.961	0.958	0.961	0.961	0.959	0.957	0.979
HC				0.926	0.924	0.923	0.887	0.911	0.879	0.970
AC				0.941	0.943	0.937	0.885	0.925	0.881	0.979
FL				0.931	0.929	0.927	0.893	0.914	0.878	0.975