Intellectual functioning in survivors of extremely low birthweight: Cognitive outcomes in childhood and adolescence.
Among ELBW survivors, those with IQ <85 had lower birthweights, more neurosensory impairment and longer ventilation, predicting worse reading and math through adolescence.
01Research in Context
What this study did
The team followed babies born at extremely low birth weight until they were teens. They wanted to know which early medical risks predict borderline IQ and poor school marks later.
Doctors weighed each baby, counted days on a ventilator, and noted any brain or hearing damage. Years later, kids took IQ tests and reading and math exams.
What they found
Children with IQ scores below 85 had the lowest birth weights and the longest ventilator stays. They also had more brain and hearing problems than peers with higher IQs.
These same kids kept scoring low in reading and math all the way through high school. The worse the early medical picture, the worse the school path.
How this fits with other research
Orío-Aparicio et al. (2025) and Milane et al. (2025) both show that people with borderline IQ struggle with daily living skills like cooking or making friends. The new study adds that these problems start early for ELBW survivors and link to clear neonatal red flags.
Peltopuro et al. (2014) warned that adults with borderline IQ earn less and need more mental-health care. Wilson et al. (2023) now trace the roots of those adult problems back to the NICU and school years, filling the developmental gap the older review could not cover.
Van der Molen et al. (2010) found that most kids with borderline IQ also move clumsily. Together, these papers paint a full picture: borderline IQ rarely travels alone—it brings motor, academic, and adaptive bumps that last.
Why it matters
If you work with former preemie clients, pull their NICU history. Low birth weight, long ventilation, or neurosensory issues should raise a red flag for later learning trouble. Add adaptive and motor screens to your IQ test battery, and start school supports early instead of waiting for failure. Targeting reading, math, and daily living together gives these kids the best shot at a smoother teen path.
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02At a glance
03Original abstract
BACKGROUND: Infants born at extremely low birthweight (ELBW: ≤1000 g) are vulnerable to intellectual disabilities, but the factors that may distinguish between ELBW survivors with and without these impairments are not well understood. In this study, prospective associations between neonatal factors and functional outcomes in childhood and adolescence were compared in ELBW survivors with and without borderline intellectual functioning (BIF). METHODS: Borderline intellectual functioning was defined by IQ < 85, assessed at 8 years. Among 146 ELBW survivors, 48 (33%) had IQ scores under 85, and 98 (67%) had scores equal to or over 85. Group differences in demographic and risk factors were assessed via t-test, chi-squared analysis or non-parametric tests. Neonatal factors that differed between ELBW groups were tested for association with adaptive behaviour assessed at age 5 years, and reading and arithmetic skills assessed at ages 8 and 15 years, using hierarchical regression models. RESULTS: Extremely low birthweight survivors with BIF had significantly lower birthweights than ELBW survivors without BIF (790 vs. 855 g, P < 0.01) and were more likely to be born to mothers with lower socioeconomic status (SES) (78% vs. 48%, P < 0.01). These ELBW survivors also were more likely to be diagnosed with significant neurosensory impairment (NSI; 35% vs. 19%, P < 0.04), experienced more bronchopulmonary dysplasia (56% vs. 38%, P < 0.04), received more days of respiratory support (median 33 vs. 14 days, P < 0.01) and remained in hospital for longer periods (median 81 vs. 63 days, P < 0.03). Birthweight, familial SES, NSI and duration of respiratory support were significant predictors for one or more outcomes. Across groups, lower familial SES was associated with lower academic scores (Ps < 0.05), and NSI predicted lower adaptive functioning (Ps < 0.001). Other associations were moderated by group: among ELBW survivors with BIF, heavier birthweights predicted better arithmetic skills, the presence of NSI was associated with poorer arithmetic skills and more ventilation days predicted poorer reading skills. CONCLUSIONS: At birth, ELBW survivors with BIF faced more physiological and social disadvantages and required more medical intervention than their ELBW peers without BIF. Smaller birth size, NSI burden and prolonged neonatal ventilatory support displayed gradients of risk for childhood and adolescent academic outcomes across groups. Whereas academic performance in ELBW survivors with BIF was sensitive to variation in birth size, NSI or ventilation days, ELBW survivors without BIF attained thresholds of intellectual ability that were sufficient to support higher levels of academic performance at both ages, regardless of their status on these factors. The findings are discussed in relation to Zigler's developmental theory of intellectual disability.
Journal of intellectual disability research : JIDR, 2023 · doi:10.1111/jir.13021