TABLE 2.

Child Characteristics by Gestational Age Groups

	Mean, SD or Weighted %
	All	Late Preterm (34–36 wk)	Early Term (37–38 wk)	Term (39–41 wk)	P*
Weighted percentage	—	9.1	28.8	62.1
Gender, male	50.5	49.5	50.9	50.5	.84
Birth weight, g	3359.2, 497.8	2873.5, 859.0	3247.8, 618.6	3481.7, 414.4	<.0001
Fetal growth
Intrauterine growth restriction (<10%, small for gestational age)	10.4	10.0	9.8	10.8	.57
5-Minute Apgar >7	97.7	93.2	97.9	98.2	<.0001
Days of hospitalization					<.0001
0–1 d	91.7	70.7	92.9	94.2
2–7 d	5.9	14.9	5.2	4.9
8–14 d	1.5	8.0	1.6	0.6
15–30 d	0.7	5.4	0.3	0.3
>30 d	0.2	1.1	0.1	0.07
Received early intervention (yes)
9 mo	1.6	3.9	1.9	1.1	.0001
24 mo	2.2	3.0	2.5	1.9	.24
Age at assessment, mo
Preschool	51.9, 5.1	52.0, 4.4	51.8, 5.2	51.9, 4.0	.39
Kindergarten	65.3, 3.6	65.5, 4.7	65.2, 4.1	65.3, 3.0	.20
Month of assessment, preschool					.38
August–October	64.4	62.0	63.4	65.1
November–January	23.1	25.8	22.6	22.9
February–June	12.6	12.1	13.9	12.0
Month of kindergarten at assessment					.32
August–October	39.9	36.7	37.5	41.6
November–January	50.4	52.5	54.0	48.4
February–June	9.7	10.8	8.5	10.0

^*P value was derived based on analysis of variance for continuous measures and χ² test for categorical data.