The relationship of prenatal and perinatal complications to cognitive functioning at age 7 in the New England cohorts of the National Collaborative Perinatal Project

Previous literature shows that children who later develop schizophrenia have elevated rates of prenatal and perinatal complications (PPCs) and neuropsychological deficits in childhood. However, little is known about the relationship of these risk factors to each other. We evaluated the relationship between PPCs and neuropsychological functioning at age 7 in a large epidemiological study of pregnancy, birth, and development: the National Collaborative Perinatal Project (NCPP). Thirteen standardized measures of cognitive abilities were acquired on 11,889 children at approximately age 7. Principal components analysis was used to create three neuropsychological measures: academic achievement skills, verbal-conceptual abilities, and perceptual-motor abilities. We measured the relationship between these factors and three measures of PPCs: low birth weight (LBW), probable hypoxicischemic complications, and chronic hypoxia. All three measures of PPCs were significantly associated with lower neuropsychological performance, after controlling for various confounders. LBW had the strongest association with neuropsychological performance, followed by an index of presumed hypoxic insults. The effect sizes between PPCs and cognitive factors at age 7 were consistently largest with perceptual-motor abilities, followed by academic achievement skills and verbal-conceptual abilities. Future studies will evaluate the effects of specific PPCs and genetic risk factors for psychosis on cognitive functioning in childhood.