Related Experiment Video

Updated: May 9, 2026

Concurrent Collection of Fetal Murine Brain and Serum to Assess Effects of Maternal Diet on Nutrition and Neurodevelopment in Neurofibromatosis Type 1
05:44

Concurrent Collection of Fetal Murine Brain and Serum to Assess Effects of Maternal Diet on Nutrition and Neurodevelopment in Neurofibromatosis Type 1

Published on: May 17, 2024

Low birth weight and intelligence in adolescence and early adulthood: a meta-analysis

C E Kormos1, A J Wilkinson2, C J Davey2

  • 1Department of Psychology, University of Victoria, Victoria, Canada V8W 3P5.

Journal of Public Health (Oxford, England)
|July 31, 2013
PubMed

Insights

Low birth weight (LBW) is linked to lower intelligence quotient (IQ) in adolescence and adulthood. This association weakens with age, though potential biases warrant cautious interpretation of findings.

Area of Science:

  • Neuroscience
  • Developmental Psychology
  • Public Health

Background:

  • Low birth weight (LBW; <2500 g) is associated with adverse intelligence quotient (IQ) outcomes in childhood.
  • The persistence of this association into late adolescence and early adulthood requires systematic evaluation.
  • The influence of age at IQ assessment on the effect size of LBW on IQ is not well understood.

Purpose of the Study:

  • To systematically evaluate if the association between LBW and IQ persists into late adolescence and early adulthood.
  • To assess the influence of age of IQ assessment on the effect size of LBW on IQ.

Main Methods:

  • A random-effects meta-analysis of 15 studies assessed IQ in individuals aged 13+ with LBW versus normal birth weight (NBW; ≥2500 g).
  • Publication bias was assessed using Rosenthal's fail-safe N and Duval and Tweedie's Trim and Fill.
  • Meta-regression was used to evaluate the effect of age at IQ assessment, incorporating data from a previous meta-analysis on children.

Main Results:

  • NBW individuals scored 7.63 IQ points higher than LBW individuals (CI = 5.95-9.31).
  • After adjusting for publication bias, NBW samples showed 4.98 IQ points higher than LBW samples (CI = 3.20-6.77).
  • Age at IQ assessment significantly moderated the LBW-IQ association, with effect size decreasing from childhood to young adulthood.

Conclusions:

  • Cognitive impairments associated with LBW persist into adolescence and early adulthood.
  • The impact of LBW on IQ diminishes from childhood into young adulthood.
  • Conclusions should be interpreted cautiously due to unmeasured variables and potential publication bias.
Abstract

Keywords:
adolescenceadulthoodintelligencelow birth weight, meta-analysis

More Related Videos

Limited Bedding and Nesting as a Model for Early-Life Adversity in Mice04:20

Limited Bedding and Nesting as a Model for Early-Life Adversity in Mice

Published on: July 12, 2024

Assessment of Child Anthropometry in a Large Epidemiologic Study09:36

Assessment of Child Anthropometry in a Large Epidemiologic Study

Published on: February 2, 2017

Related Concept Videos

Biological Influences on Intelligence01:30

Biological Influences on Intelligence

Intelligence is often thought to be linked to brain size, but the relationship is more complex than that. While brain size does correlate modestly with some abilities, like verbal skills, the connection is weaker for others, such as spatial reasoning. Other factors, like brain structure, also play crucial roles. For instance, despite Einstein's smaller-than-average brain, his parietal cortex, which is involved in spatial reasoning, was 15% wider, suggesting that neural density might matter more...
Environmental Influences on Intelligence01:29

Environmental Influences on Intelligence

Despite the strong genetic influence on traits like intelligence, environmental factors significantly shape outcomes. For example, while over 90% of height variation is due to genetic differences, environmental factors such as nutrition also have a notable impact. Similarly, for intelligence, changes in a child's surroundings can significantly alter their IQ. Research shows that enriched environments boost children's academic success and help them develop key cognitive skills. Children from...
Regression Toward the Mean01:52

Regression Toward the Mean

Regression toward the mean (“RTM”) is a phenomenon in which extremely high or low values—for example, and individual’s blood pressure at a particular moment—appear closer to a group’s average upon remeasuring. Although this statistical peculiarity is the result of random error and chance, it has been problematic across various medical, scientific, financial and psychological applications. In particular, RTM, if not taken into account, can interfere when researchers try to extrapolate results...
Attention-Deficit/Hyperactivity Disorder01:30

Attention-Deficit/Hyperactivity Disorder

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by persistent inattention, hyperactivity, and impulsivity. It affects approximately 5-8% of children globally, with around 60-70% of cases persisting into adulthood. ADHD has significant implications for educational attainment, social interactions, and occupational success.
Diagnostic Criteria and Symptoms
To diagnose ADHD, symptoms must manifest before age 12 and be evident across multiple settings.
Human Genetics01:28

Human Genetics

Human genetics provides a profound framework for understanding the interplay between genetic predispositions and human psychology. At the heart of this discipline lies the study of how genes influence physical traits, behaviors, and susceptibility to diseases. Each person carries a unique genetic code that subtly or significantly shapes their psychological and behavioral landscape.
The complex relationship between genetics and psychology is observable through common biological components such...
Nature and Nurture01:10

Nature and Nurture

Many human characteristics, like height, are shaped by both nature—in other words, by our genes—and by nurture, or our environment. For example, chronic stress during childhood inhibits the production of growth hormones and consequently reduces bone growth and height. Scientists estimate that 70-90% of variation in height is due to genetic differences among individuals, and 10-30% of variation in height is due to differences in the environments that individuals experience, such as differences...