While the IQ of adults born very prematurely or of very low birth weight can be predicted when they are just toddlers, the same research found that the IQ of adults who were born full-term could not be accurately predicted until age six. Prior research has shown that very premature birth and very low birth weight have resulted in impaired cognitive function from childhood and throughout adulthood, but it had not been clear how soon adult IQ could be predicted in these children, according to an article in the journal Pediatrics that was reported in Futurity
As Dieter Wolke, a psychology professor at the University of Warwick, explained, “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. 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.”
According to HowStuffWorks
, IQ tests are designed to measure one’s general ability to solve problems and understand concepts. This includes reasoning ability, problem-solving ability, ability to perceive relationships between things and ability to store and retrieve information. IQ tests measure this general intellectual ability in a number of different ways.
In terms of all of the assessments in the study, very premature and very low birth weight children and adults had lower IQ scores than those born full-term, even when researchers excluded individuals with severe cognitive impairment from the comparisons. The researchers conducted the study, called the Bavarian Longitudinal Study, in southern Bavaria, Germany. They followed children who were born between 1985 and 1986 from birth into adulthood. Data gained on cognitive function were assessed with developmental and intelligence tests (IQ) at five and 20 months and at four, six, eight, and 26 years of age.
Of the babies two-hundred-and-sixty born either very premature (before 32 weeks) or with very low birth weight (fewer than 1.5 kg) were compared with 229 who were born full-term. Their results were not sex-specific or related to income or education. They were compared to the control group of adults who were born healthy in the same obstetric wards.
According to Wolke, “Some children born very premature or with very low birth weight scored low on cognitive tests but beat the odds and improved into adulthood. 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.”