Small for Gestational Age Moderate to Late Preterm Children: A Neuropsychological Follow-up

Figures & data

Figure 1. Sample recruitment flow chart for both SGA and AGA preterms

Table 1. Sociodemographic and perinatal characteristics of the SGA and AGA groups

	SGA (n = 109)	AGA (n = 109)
	M (SD)	M (SD)	t
Gestational Age (weeks+days)	35 + 0 (1 + 2)	35 + 0 (1 + 2)	0.148
Birth weight (kg)	1.76 (0.31)	2.40 (0.42)	−12.684***
Birth length (cm)	42.89 (2.62)	45.73 (2.40)	−8.383***
Birth head circumference (cm)	30.44 (1.70)	32.10 (1.48)	−7.749***
Maternal age (years)	34.35 (4.56)	34.03 (4.02)	0.485
Days in hospital	22.48 (14.64)	9.17 (9.16)	8.040***
	N (%)	N (%)	X^2
Sex
Boy	63 (57.8)	63 (57.8)	0.000
Girl	46 (42.2)	46 (42.2)
Multiple birth
Yes	57 (52.3)	57 (52.3)	0.000
No	52 (47.7)	52 (47.7)
Mode of delivery
Cesarean section	56 (51.4)	36 (33.0)	7.900*
Instrumental	18 (16.5)	21 (19.3)
Eutocic	35 (32.1)	52 (47.7)
Socioeconomic level
< 12.000 euros	9 (8.8)	6 (6.5)	3.051
>12.000– 24.000 euros	29 (28.4)	19 (20.7)
>24.000– 36.000 euros	30 (29.4)	28 (30.4)
>36.000– 48.000 euros	21 (20.6)	21 (22.8)
> 48.000 euros	13 (12.7)	18 (19.6)
Maternal education
Elementary school	16 (14.8)	8 (7.5)	7.438*
Secondary education	49 (45.4)	37 (34.9)
University	43 (39.8)	63 (57.5)

Note. SGA: Small for Gestational Age; AGA: Adequate for Gestational Age

* p < .05; *** p < .001.

Figure 2. Mean scores for the Bayley scales in the SGA and AGA groups

Note: * p < .001. The dashed line represents the normative mean and the shaded area represents the clinically normal range. Error bars indicate standard error.

Table 2. Neuropsychological performance of the SGA and AGA groups at Timepoint 2: ANCOVA controlling for maternal education

	SGA Adj. M (SE)	AGA Adj. M (SE)	F	p	Hedges’ g	% of clinically relevant scores
						SGA	AGA
WISC-V Indexes
VCI	94.00 (1.30)	92.80 (1.26)	0.43	.514	0.10	19.8	25.8
VSI	100.41 (1.31)	101.86 (1.27)	0.62	.431	0.12	6.2	4.5
FRI	100.51 (1.24)	100.38 (1.19)	0.01	.938	0.01	7.5	5.6
WMI	93.05 (1.45)	97.17 (1.40)	4.14	.043	0.32	28.4	15.7*
PSI	99.30 (1.40)	100.06 (1.35)	0.15	.696	0.06	8.6	7.9
FSIQ	95.92 (1.22)	96.76 (1.17)	0.24	.623	0.08	16.3	10.1
ENFEN
Semantic fluency	53.09 (1.27)	51.01 (1.12)	1.48	.226	0.21	8.1	19.8
Phonetic fluency	39.57 (1.09)	39.46 (0.97)	0.01	.944	0.01	50.0	53.8
Ring- building time	65.49 (2.22)	65.04 (1.98)	0.02	0.883	0.03	54.8	48.8
CSAT-R
d’	30.90 (2.31)	37.70 (2.05)	4.77	.031	0.38	74.2	52.5**
Correct answers	42.25 (1.10)	46.68 (0.98)	8.86	.003	0.52	33.9	22.5
Commissions	55.89 (1.44)	54.54 (1.28)	0.48	.489	0.11	48.4	40.0
TOMAL
Total recall	45.63 (1.12)	46.47 (0.99)	0.31	.576	0.10	68.3	61.7
SMB
Pseudoword repetition	47.56 (1.38)	46.42 (1.22)	0.38	.540	0.11	27.4	22.2
CEG
Correct	46.66 (1.29)	44.80 (1.13)	1.16	.283	0.21	14.9	27.4
Blocks	46.32 (1.15)	45.56 (1.00)	0.25	.619	0.10	14.9	27

Note. SGA: Small for Gestational Age; AGA: Adequate for Gestational Age; WISC-V: Wechsler Intelligence Scale for Children; VCI: Verbal Comprehension Index; VSI: Visuo-spatial Index; FRI: Fluid Reasoning Index; WMI: Working Memory; PSI: Processing Speed Index; FSIQ: Full Scale Intelligence Quotient; ENFEN: “Neuropsychological evaluation of executive functioning in children” [Evaluación Neuropsicológica de las Funciones Ejecutivas en Niños]; CSAT: Children Sustained Attention Task; TOMAL: Test of Memory and Learning; SMB: Spreen-Benton language test; CEG: “Grammatical structures comprehension test” [Test de comprensión de estructuras gramaticales].

Note. Differences marked in bold are statistically significant; Adj. M: Adjusted Mean; SE: Standard Error.

*p < .05. **p < .01. ***p < .001.

Table 3. Spearman’s correlations between toddler psychomotor development at 2 years old CA and cognitive and academic functioning at age 6.5 years for the SGA and AGA groups

	WISC-V						Academic Performance						CSAT-R			TOMAL	SMB			ENFEN							CEG
	VCI	VSI	FRI	WMI	PSI	FSIQ	M	R	W	OL	LC	PE	d	Correct	Commission	Recall	Pseudo-words		Semantic fluency			Phonetic fluency				Correct		Block
SGA
COG	.21	.28*	.41**	.52**	.36**	.45**	.28*	.34**	.34**	.27*	.27*	.15	.24	−.10	−.34**	.20	.12		.32*			−.01				.21		.20
RC	.17	.11	.24*	.44**	.17	.31**	.10	.26*	.21	.29*	.30*	.21	.12	.08	−.11	.25	.07		.16			−.01				.33*		.20
EC	.24*	.24*	.29*	.32**	.23*	.33**	.31*	.29*	.34**	.17	.13	.06	.05	−.10	−.12	.12	.17		.10			.10				.22		.13
FM	.01	.29**	.19	.43**	.24*	.20	.29*	.14	.14	.11	.06	.15	.23	.10	−.21	.37**	.07		.30*			.14				.20		.16
GM	.15	.07	.05	.29**	.13	.13	.04	.01	−.08	−.12	−.07	.10	.15	.18	−.05	.23	.11		.22			−.05				.07		−.01
AGA
COG	.05	.21*	.23*	.16	.40**	.27*	.38**	.17	.18	.24*	.18	.24*	.30**	.16	−.18	.16	.28*			.05		.06				.14		.33**
RC	.04	.22*	.17	.05	.15	.19	.26*	.19	.19	.04	.08	.12	.24*	.17	−.12	.19	.28*			.26*		.20				.23		.31*
EC	.17	.08	−.07	.15	−.15	.09	.06	−.01	.05	−.06	−.10	−.01	.20	.11	−.12	−.07	.17			.16		−.08				−.02		−.02
FM	.01	.13	.12	−.02	.17	.05	.43**	.07	.19	−.01	−.05	.39**	.23*	.16	−.16	−.03	.08			.10		−.03				−.10		−.01
GM	−.07	.10	.08	.02	.19	.01	.29*	.10	.12	.15	.12	.24*	.21	.21	−.13	.19	.08			−.03		.17				−.05		−.04

Note: SGA: Small for Gestational Age; AGA: Adequate for Gestational Age; WISC-V: Wechsler Intelligence Scale for Children; VCI: Verbal Comprehension Index; VSI: Visuo-spatial Index; FRI: Fluid Reasoning Index; WMI: Working Memory; PSI: Processing Speed Index; FSIQ: Full Scale Intelligence Quotient; M = Math; R = Reading, W = Writing; OL = Oral language; LC = Language comprehension; PE = Physical Education; CSAT: Children Sustained Attention Task; TOMAL: Test of Memory and Learning; SMB: Spreen-Benton language test; ENFEN: “Neuropsychological evaluation of executive functioning in children” [Evaluación Neuropsicológica de las Funciones Ejecutivas en Niños]; CEG: “Grammatical structures comprehension test” [Test de comprensión de estructuras gramaticales]. From Bayley-III: COG: Cognitive; RC: Receptive Communication; EC: Expressive Communication; FM: Fine Motor; GM: Gross Motor.

*p < .05. **p < .01. ***p < .001.

Data availability statement

Derived data supporting the findings of this study are available from the corresponding author G.L. on request.