The adult IQ (intelligence quotient) of babies born very prematurely or with very low birth weight can be predicted when they are just toddlers, say researchers from the University of Warwick.
Prior research has linked very premature birth and very low birth weight with impaired cognitive function in both children and adults, but it remained unclear how soon adult IQ could be predicted in these children.
“We believe this is the first time a research paper has looked into the prediction of the IQ of adults over the age of 26 who were born very premature or with very low birth weight,” said lead researcher Professor Dieter Wolke from the department of psychology and Warwick Medical School.
“The results indicate that assessing two year olds who were born very preterm or very underweight will provide a reasonably good prediction to what their adult IQ will be.”
In contrast, the findings showed that the IQ of adults who were born full-term couldn’t be accurately predicted until the age of six.
Across all assessments within the study, very premature and very low birth weight children and adults had lower IQ scores than those born full-term, even when those with severe cognitive impairment were excluded from the comparisons.
The study used data from the Bavarian Longitudinal Study conducted in southern Bavaria, Germany. Researchers followed children from birth into adulthood who were born between 1985-86. Data on cognitive function was assessed with developmental and intelligence tests (IQ) at five and 20 months and at four, six, eight, and 26 years of age.
Researchers compared 260 babies born either very prematurely (before 32 weeks) or with very low birth weight (fewer than 3.3 lbs) to 229 babies who born full-term. Their results were not gender-specific, related to income, or education, and were compared to the control group of adults who were born healthy in the same obstetric wards.
“Some children born very premature or with very low birth weight score low on cognitive tests but beat the odds and improve into adulthood,” said Wolke.
“However many with persistent problems can be detected in the second year of life. Early identification of cognitive problems in these children may help to plan specialized therapeutic and educational interventions to help them and their families.”
The research paper is published in the journal Pediatrics.
Source: University of Warwick