Premature babies at a moderate or even minor risk for birth-related hypoxia--oxygen deprivation within the body--score lower on IQ tests and language skills in childhood, according to a study published in the January issue of Neuropsychology (Vol. 17, No. 1). The study was conducted by psychologists Sarah Raz, PhD, and Tracy Hopkins-Golightly, PhD, and neonatologist Craig J. Sanders, MD.
The researchers evaluated 52 children born at or before 36 weeks of gestation. Of that group, 26 children had a slight to moderate risk of hypoxia. All the children were tested at 5 or 6 years old on verbal and nonverbal intelligence and receptive and expressive language skills.
Children who had been at risk for hypoxia scored 10 points lower on average on IQ tests compared with those who had not been at risk. Also, those who had been at higher risk for hypoxia tended to score the lowest in cognitive performance and expressive communication.
"This research is a piece in a very large puzzle," says Raz, associate professor in the Merrill-Palmer Institute and the department of psychology at Wayne State University. "There is a lot to be learned about brain vulnerability during early human development. I think that knowledge will be gained more quickly with increased awareness that perinatal insults vary in severity and that all segments of the severity continuum deserve attention."