Ultrasound Measurements of Fetal Thyroid: Reference Ranges from a Cohort of Low-Risk Pregnant Women

Table 4

Fitted 10th, 50th, and 90th centiles of thyroid lobe longitudinal diameter, anteroposterior diameter, and transverse diameter and volume at 14 to 40 weeks of gestation (mm and mm³).

Longitudinal diameter (mm)				Anteroposterior diameter (mm)				Transverse diameter (mm)				Volume (mm^3)
Centiles				Centiles				Centiles				Centiles
GA	10th	50th	90th	GA	10th	50th	90th	GA	10th	50th	90th	GA	10th	50th	90th
14	5.00	6.80	8.85	14	2.05	2.88	3.64	14	2.46	3.13	4.10	14
15	5.44	7.31	9.43	15	2.21	3.09	3.91	15	2.63	3.35	4.39	15
16	5.89	7.82	10.02	16	2.38	3.30	4.17	16	2.79	3.58	4.68	16	20.75	21.08	29.92
17	6.33	8.34	10.60	17	2.54	3.50	4.44	17	2.95	3.80	4.96	17	32.74	44.17	71.75
18	6.77	8.85	11.18	18	2.70	3.71	4.70	18	3.12	4.02	5.25	18	44.73	67.25	113.59
19	7.22	9.36	11.77	19	2.86	3.91	4.96	19	3.28	4.24	5.54	19	56.72	90.34	155.42
20	7.66	9.87	12.35	20	3.02	4.12	5.23	20	3.44	4.47	5.83	20	68.70	113.43	197.25
21	8.10	10.38	12.93	21	3.18	4.32	5.49	21	3.61	4.69	6.12	21	80.69	136.51	239.09
22	8.54	10.90	13.52	22	3.35	4.53	5.76	22	3.77	4.91	6.41	22	92.68	159.60	280.92
23	8.99	11.41	14.10	23	3.51	4.73	6.02	23	3.93	5.14	6.69	23	104.66	182.68	322.75
24	9.43	11.92	14.68	24	3.67	4.94	6.29	24	4.10	5.36	6.98	24	116.65	205.77	364.59
25	9.87	12.43	15.27	25	3.83	5.15	6.55	25	4.26	5.58	7.27	25	128.64	228.86	406.42
26	10.32	12.94	15.85	26	3.99	5.35	6.82	26	4.42	5.80	7.56	26	140.62	251.94	448.25
27	10.76	13.46	16.43	27	4.15	5.56	7.08	27	4.59	6.03	7.85	27	152.61	275.03	490.09
28	11.20	13.97	17.02	28	4.31	5.76	7.35	28	4.75	6.25	8.13	28	164.60	298.11	531.92
29	11.64	14.48	17.60	29	4.48	5.97	7.61	29	4.91	6.47	8.42	29	176.58	321.20	573.75
30	12.09	14.99	18.18	30	4.64	6.17	7.88	30	5.07	6.69	8.71	30	188.57	344.28	615.59
31	12.53	15.50	18.77	31	4.80	6.38	8.14	31	5.24	6.92	9.00	31	200.56	367.37	657.42
32	12.97	16.02	19.35	32	4.96	6.58	8.41	32	5.40	7.14	9.29	32	212.54	390.45	699.25
33	13.42	16.53	19.93	33	5.12	6.79	8.67	33	5.56	7.36	9.58	33	224.53	413.54	741.08
34	13.86	17.04	20.52	34	5.28	7.00	8.94	34	5.73	7.59	9.86	34	236.52	436.63	782.92
35	14.30	17.55	21.10	35	5.44	7.20	9.20	35	5.89	7.81	10.15	35	248.51	459.71	824.75
36	14.74	18.06	21.68	36	5.61	7.41	9.46	36	6.05	8.03	10.44	36	260.49	482.80	866.58
37	15.19	18.58	22.27	37	5.77	7.61	9.73	37	6.22	8.25	10.73	37	272.48	505.88	908.42
38	15.63	19.09	22.85	38	5.93	7.82	9.99	38	6.38	8.48	11.02	38	284.47	528.97	950.25
39	16.07	19.60	23.43	39	6.09	8.02	10.26	39	6.54	8.70	11.30	39	296.45	552.05	992.08
40	16.52	20.11	24.02	40	6.25	8.23	10.52	40	6.71	8.92	11.59	40	308.44	575.14	1033.92