Table 3.

Number of classified true or false, positive or negative FGR cases for various BLWR thresholds by gestational age^∗

Group	FGR†		FGR based on BLWR
	No	Yes	Ratio	No	Yes	FP	FN	TP	TN
All ages	266	90	2.8	195	161	103	32	58	163
			3.0	230	126	72	36	54	194
			3.5	285	71	31	50	40	235
			4.0	317	39	10	61	29	256
			4.5	333	23	3	70	20	263
			5.0	338	18	0	72	18	266
			3.3‡	267	89	43	44	46	223
<28 weeks	153	28	2.8	100	81	64	11	17	89
			3.0	117	64	47	11	17	106
			3.5	145	36	20	12	16	133
			4.0	161	20	7	15	13	146
			4.5	170	11	2	19	9	151
			5.0	173	8	0	20	8	153
			3.7‡	151	30	14	12	16	139
≥28 weeks	113	62	2.8	95	80	39	21	41	74
			3.0	113	62	25	25	37	88
			3.5	140	35	11	38	24	102
			4.0	156	19	3	46	16	110
			4.5	163	12	1	51	11	112
			5.0	165	10	0	52	10	113
			3.0‡	113	62	25	25	37	88

BLWR, brain to liver weight ratio; FGR, fetal growth restriction; FN, false negative; FP, false positive; TN, true negative; TP, true positive.

^*Excludes central nervous system conditions or chromosomal anomalies.

^†Defined using weight for gestational age <10th percentile or discordant birth weight/length.

^‡Optimal BLWR threshold for classifying FGR based on Youden's index.