The Effect of Intrauterine Growth on Verbal IQ Scores in Childhood: A Study of Monozygotic Twins

Caroline J. Edmonds; Elizabeth B. Isaacs; Tim J. Cole; Mary Haslinger Rogers; Julie Lanigan; Atul Singhal; Toni Birbara; Paul Gringras; Jane Denton; Alan Lucas

doi:10.1542/peds.2008-3684

The Effect of Intrauterine Growth on Verbal IQ Scores in Childhood: A Study of Monozygotic Twins

Caroline J. Edmonds^*, Elizabeth B. Isaacs, Tim J. Cole, Mary Haslinger Rogers, Julie Lanigan, Atul Singhal, Toni Birbara, Paul Gringras, Jane Denton, Alan Lucas

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

45 Citations (Scopus)

Abstract

OBJECTIVE: Given the adverse neurobiological effects of suboptimal nutrition on the developing brain, it is of social and medical importance to determine if the global prevalence of poor intrauterine growth causes lasting cognitive deficits. We examined whether suboptimal intrauterine growth relates to impaired cognitive outcome by comparing birth weight and cognition in monozygotic twins and considered whether children within-pair differences in birth weight were related to within-pair differences in IQ scores.

METHODS: A total of 71 monozygotic twin pairs (aged 7 years 11 months to 17 years 3 months) participated. The Wechsler Intelligence Scale for Children, Third Edition, was administered, and verbal IQ (VIQ) and performance IQ (PIQ) scores were calculated. Regression was used to relate within-pair differences in birth weight to within-pair differences in IQ scores.

RESULTS: VIQ but not PIQ score was affected by prenatal growth restriction. The results suggest that the mean advantage for heavier twins relative to their lighter co-twins can be as much as half an SD in VIQ points. In pairs with minimal discordance, heavier twins had lower VIQ scores than their lighter co-twins.

CONCLUSIONS: Our study results suggest that lower birth weight in monozygotic twins can also have a negative long-term impact on cognition both in infants who are small at birth and also those with birth weights across the spectrum. Studying monozygotic twins enabled us to examine the effect of reduced intrauterine growth on cognition independently of confounding factors, including parental IQ and education and infant gender, age, genetic characteristics, and gestation.

Original language	English
Pages (from-to)	E1095-E1101
Number of pages	7
Journal	Pediatrics
Volume	126
Issue number	5
DOIs	https://doi.org/10.1542/peds.2008-3684
Publication status	Published - Nov 2010

Keywords

cognitive function
intellectual functioning
intrauterine growth retardation
twins
LOW-BIRTH-WEIGHT
GESTATIONAL-AGE
PRETERM INFANTS
INTELLIGENCE QUOTIENT
COGNITIVE FUNCTION
ABERDEEN CHILDREN
RANDOMIZED-TRIAL
DEVELOPING BRAIN
COHORT
MYELINATION

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@article{06d9a94e49ac473baa2581077b4dccfe,

title = "The Effect of Intrauterine Growth on Verbal IQ Scores in Childhood: A Study of Monozygotic Twins",

abstract = "OBJECTIVE: Given the adverse neurobiological effects of suboptimal nutrition on the developing brain, it is of social and medical importance to determine if the global prevalence of poor intrauterine growth causes lasting cognitive deficits. We examined whether suboptimal intrauterine growth relates to impaired cognitive outcome by comparing birth weight and cognition in monozygotic twins and considered whether children within-pair differences in birth weight were related to within-pair differences in IQ scores.METHODS: A total of 71 monozygotic twin pairs (aged 7 years 11 months to 17 years 3 months) participated. The Wechsler Intelligence Scale for Children, Third Edition, was administered, and verbal IQ (VIQ) and performance IQ (PIQ) scores were calculated. Regression was used to relate within-pair differences in birth weight to within-pair differences in IQ scores.RESULTS: VIQ but not PIQ score was affected by prenatal growth restriction. The results suggest that the mean advantage for heavier twins relative to their lighter co-twins can be as much as half an SD in VIQ points. In pairs with minimal discordance, heavier twins had lower VIQ scores than their lighter co-twins.CONCLUSIONS: Our study results suggest that lower birth weight in monozygotic twins can also have a negative long-term impact on cognition both in infants who are small at birth and also those with birth weights across the spectrum. Studying monozygotic twins enabled us to examine the effect of reduced intrauterine growth on cognition independently of confounding factors, including parental IQ and education and infant gender, age, genetic characteristics, and gestation.",

keywords = "cognitive function, intellectual functioning, intrauterine growth retardation, twins, LOW-BIRTH-WEIGHT, GESTATIONAL-AGE, PRETERM INFANTS, INTELLIGENCE QUOTIENT, COGNITIVE FUNCTION, ABERDEEN CHILDREN, RANDOMIZED-TRIAL, DEVELOPING BRAIN, COHORT, MYELINATION",

author = "Edmonds, {Caroline J.} and Isaacs, {Elizabeth B.} and Cole, {Tim J.} and Rogers, {Mary Haslinger} and Julie Lanigan and Atul Singhal and Toni Birbara and Paul Gringras and Jane Denton and Alan Lucas",

year = "2010",

month = nov,

doi = "10.1542/peds.2008-3684",

language = "English",

volume = "126",

pages = "E1095--E1101",

journal = "Pediatrics",

issn = "0031-4005",

publisher = "American Academy of Pediatrics",

number = "5",

}

TY - JOUR

T1 - The Effect of Intrauterine Growth on Verbal IQ Scores in Childhood

T2 - A Study of Monozygotic Twins

AU - Edmonds, Caroline J.

AU - Isaacs, Elizabeth B.

AU - Cole, Tim J.

AU - Rogers, Mary Haslinger

AU - Lanigan, Julie

AU - Singhal, Atul

AU - Birbara, Toni

AU - Gringras, Paul

AU - Denton, Jane

AU - Lucas, Alan

PY - 2010/11

Y1 - 2010/11

N2 - OBJECTIVE: Given the adverse neurobiological effects of suboptimal nutrition on the developing brain, it is of social and medical importance to determine if the global prevalence of poor intrauterine growth causes lasting cognitive deficits. We examined whether suboptimal intrauterine growth relates to impaired cognitive outcome by comparing birth weight and cognition in monozygotic twins and considered whether children within-pair differences in birth weight were related to within-pair differences in IQ scores.METHODS: A total of 71 monozygotic twin pairs (aged 7 years 11 months to 17 years 3 months) participated. The Wechsler Intelligence Scale for Children, Third Edition, was administered, and verbal IQ (VIQ) and performance IQ (PIQ) scores were calculated. Regression was used to relate within-pair differences in birth weight to within-pair differences in IQ scores.RESULTS: VIQ but not PIQ score was affected by prenatal growth restriction. The results suggest that the mean advantage for heavier twins relative to their lighter co-twins can be as much as half an SD in VIQ points. In pairs with minimal discordance, heavier twins had lower VIQ scores than their lighter co-twins.CONCLUSIONS: Our study results suggest that lower birth weight in monozygotic twins can also have a negative long-term impact on cognition both in infants who are small at birth and also those with birth weights across the spectrum. Studying monozygotic twins enabled us to examine the effect of reduced intrauterine growth on cognition independently of confounding factors, including parental IQ and education and infant gender, age, genetic characteristics, and gestation.

AB - OBJECTIVE: Given the adverse neurobiological effects of suboptimal nutrition on the developing brain, it is of social and medical importance to determine if the global prevalence of poor intrauterine growth causes lasting cognitive deficits. We examined whether suboptimal intrauterine growth relates to impaired cognitive outcome by comparing birth weight and cognition in monozygotic twins and considered whether children within-pair differences in birth weight were related to within-pair differences in IQ scores.METHODS: A total of 71 monozygotic twin pairs (aged 7 years 11 months to 17 years 3 months) participated. The Wechsler Intelligence Scale for Children, Third Edition, was administered, and verbal IQ (VIQ) and performance IQ (PIQ) scores were calculated. Regression was used to relate within-pair differences in birth weight to within-pair differences in IQ scores.RESULTS: VIQ but not PIQ score was affected by prenatal growth restriction. The results suggest that the mean advantage for heavier twins relative to their lighter co-twins can be as much as half an SD in VIQ points. In pairs with minimal discordance, heavier twins had lower VIQ scores than their lighter co-twins.CONCLUSIONS: Our study results suggest that lower birth weight in monozygotic twins can also have a negative long-term impact on cognition both in infants who are small at birth and also those with birth weights across the spectrum. Studying monozygotic twins enabled us to examine the effect of reduced intrauterine growth on cognition independently of confounding factors, including parental IQ and education and infant gender, age, genetic characteristics, and gestation.

KW - cognitive function

KW - intellectual functioning

KW - intrauterine growth retardation

KW - twins

KW - LOW-BIRTH-WEIGHT

KW - GESTATIONAL-AGE

KW - PRETERM INFANTS

KW - INTELLIGENCE QUOTIENT

KW - COGNITIVE FUNCTION

KW - ABERDEEN CHILDREN

KW - RANDOMIZED-TRIAL

KW - DEVELOPING BRAIN

KW - COHORT

KW - MYELINATION

U2 - 10.1542/peds.2008-3684

DO - 10.1542/peds.2008-3684

M3 - Article

SN - 0031-4005

VL - 126

SP - E1095-E1101

JO - Pediatrics

JF - Pediatrics

IS - 5

ER -

The Effect of Intrauterine Growth on Verbal IQ Scores in Childhood: A Study of Monozygotic Twins

Abstract

Keywords

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