The association of gestational duration and birth weight with child IQ: The generation R study

BACKGROUND: Several psychiatric disorders are considered to be neurodevelopmental in origin. Population-based research provides us with a unique opportunity to explore how prenatal factors influence neurodevelopment. AIM: To analyse whether non-verbal child iq is linked to gestational duration and birth weight and to find out whether these birth factors can be seen as to reflect the intra-uterine environment. METHOD: Participants were 5, 893 (73.6%) children enrolled in the Generation R Study. The gestational duration was determined on the basis of foetal ultrasound scans. Birth weight was measured and transformed into standard deviation scores corrected for gestational duration and gender. The nonverbal iq was measured when the child reached the age of six. RESULTS: Even during in the a-term period, gestational duration showed a linear association with non-verbal IQ, whereas the association between birth weight and non-verbal IQ was found to be curvilinear. CONCLUSION: Independently and showing different patterns, both gestational duration and birth weight were found to have a predictive value for childhood non-verbal IQ. This finding illustrates the various mechanisms that could lead to neurodevelopmental disorders.