Table 1:

Median, 5th, and 95th percentiles for SI measurements

Gestational Age (wk)	Imaging Modality
	US 2D			US 3D			MRI
	%5	Median	%95	%5	Median	%95	%5	Median	%95
21	10.69	11.95	12.57	11.10	12.30	14.60
22	10.42	12.72	14.40	11.50	13.60	14.90
23	11.71	12.79	13.84	13.00	14.40	16.50
24	13.33	13.79	14.82	13.40	15.35	17.50
25	13.85	15.17	16.66	14.50	16.00	17.80
26	13.75	16.09	18.45	15.60	16.80	19.50
27	14.05	17.07	18.78	16.70	18.70	20.20	13.30	14.13	15.05
28	16.08	17.09	19.72	16.30	18.80	23.80	13.66	14.58	15.73
29	17.29	18.72	20.33	18.10	20.00	22.20	13.25	16.02	17.54
30	17.83	18.56	19.62	18.40	20.50	23.60	15.77	17.38	20.76
31	18.03	19.34	20.75	18.10	21.30	23.80	16.16	18.02	19.34
32	17.68	19.33	20.59	19.00	21.40	26.60	16.75	18.67	20.12
33	16.78	20.93	22.94	20.70	22.70	24.50	18.37	19.48	21.21
34	19.11	20.38	23.34	20.40	22.30	28.50	17.90	19.56	21.30
35	19.62	21.75	24.29	20.90	22.00	27.00	18.27	19.83	23.29

Note:—%5 indicates 5th percentile; %95, 95th percentile.