Association of Intrauterine Growth Restriction and Small for Gestational Age Status With Childhood Cognitive Outcomes

Abstract

The magnitude of the association of intrauterine growth restriction (IUGR) and small for gestational age (SGA) status with cognitive outcomes in preterm and term-born children has not been established.OBJECTIVE To examine cognitive outcomes of preterm and term-born children who had IUGR and were SGA compared with children who were appropriate for gestational age (AGA) during the first 12 years of life.DATA SOURCES For this systematic review and meta-analysis, the Scopus, PubMed, Web of Science, Science Direct, PsycInfo, and ERIC databases were searched for English-language, peer-reviewed literature published between January 1, 2000, and February 20, 2020. The following Medical Subject Heading terms for IUGR and SGA and cognitive outcomes were used: intrauterine growth restriction, intrauterine growth retardation, small for gestational age AND neurodevelopment, neurodevelopmental outcome, developmental outcomes, and cognitive development.STUDY SELECTION Inclusion criteria were assessment of cognitive outcomes (full-scale IQ or a cognitive subscale), inclusion of an AGA group as comparison group, and inclusion of gestational age at birth and completion of cognitive assessment up to 12 years of age. DATA EXTRACTION AND SYNTHESISThe Meta-analysis of Observational Studies in Epidemiology (MOOSE) reporting guidelines were followed. Data were double screened for full-text articles, and a subset were independently coded by 2 authors. Standardized mean differences (SMDs) and odd ratios from individual studies were pooled by applying random-effects models. MAIN OUTCOMES AND MEASURESCognitive outcomes, defined as mental, cognitive, or IQ scores, estimated with standardized practitioner-based cognitive tests or as borderline intellectual impairment (BII), defined as mental, cognitive, or IQ scores at least 1 SD below the mean cognitive score. RESULTSIn this study of 89 samples from 60 studies including 52 822 children, children who had IUGR and were SGA had significantly poorer cognitive outcomes (eg, cognitive scores and BII) than children with AGA in childhood. For cognitive scores, associations are consistent for preterm (SMD, −0.27; 95% CI, −0.38 to −0.17) and term-born children (SMD, −0.39; 95% CI, −0.50 to −0.28), with higher effect sizes reported for term-born IUGR and AGA group comparisons (SMD, -0.58; 95% CI, -0.82 to -0.35). Analyses on BII revealed a significantly increased risk in the preterm children who had IUGR and were SGA (odds ratio, 1.57; 95% CI, 1.40-1.77) compared with the children with AGA.CONCLUSIONS AND RELEVANCE Growth vulnerabilities assessed antenatally (IUGR) and at the time of birth (SGA) are significantly associated with lower childhood cognitive outcomes in preterm and term-born children compared with children with AGA. These findings highlight the need to develop interventions that boost cognitive functions in these high-risk groups.

Birth weight is associated with brain tissue volumes seven decades later, but not with age-associated changes to brain structure

“…The Developmental Origins of Health and Disease hypothesis, formulated by David Barker, posits that the fetal development influences health and disease risk throughout the life course (1). Birth weight, an indicator of fetal growth, is associated with cardiovascular disease risk (2), and neurological and psychiatric outcomes from early life into adulthood (3), as well as early life cognitive (4,5). Higher cognitive ability in early life is associated with reduced risk of dementia and cognitive decline in later life (6)(7)(8).…”

Motor and cognitive outcomes of low birth weight neonates born in a limited resource country: a systematic review

“…Intrauterine growth restriction (IUGR) is an abnormal fetal growth standard that happens in approximately ten percent of gestations and is related with neonatal morbidity and mortality 6 IUGR is a condition in which the fetus does not reach the expected weight during pregnancy, is defined as a rate of fetal growth that is less than normal for the expected growth potential of a particular infant, because of genetic or environmental factors, 7 it is a pathologic inhibition of intrauterine fetal growth and the failure of the fetus to achieve its growth potential 8 . In IUGR pregnancies, the fetus attempts to prevent damage by slowing its growth and shortening its gestation, causing prematurity.…”

“…In IUGR pregnancies, the fetus attempts to prevent damage by slowing its growth and shortening its gestation, causing prematurity. 6 The terms IUGR and small for gestational age (SGA) have been used as equals in the literature, although there is a difference. IUGR reflects fetal suffering, though SGA only provides a measure of size and not a measure of antenatal growth quality.…”

“…IUGR reflects fetal suffering, though SGA only provides a measure of size and not a measure of antenatal growth quality. 6 SGA is a term used to describe neonates whose birth weight is bellow than the usual amount for the number of weeks of pregnancy, they usually are below the 10th percentile for babies of the same gestational age, or 2 deviations below. 7 Subjects born with IUGR experience several poorer developmental outcomes, involving cognitive, socioemotional and behavioral domains, compared with children born appropriate for gestational age.…”

“…7 Subjects born with IUGR experience several poorer developmental outcomes, involving cognitive, socioemotional and behavioral domains, compared with children born appropriate for gestational age. 6 IUGR is one of the main causes of perinatal and neonatal morbidity and mortality and contributes to long-term chronic diseases. [7][8][9] Neurodevelopmental impairment, immediate perinatal adverse events (prematurity, cerebral palsy, intrauterine fetal death, neonatal death) and also to adult pathologic conditions are leading consequences of the IUGR.…”