Association of Maternal Cumulative Risk during Pregnancy and IQ in Preschoolers: Role of Glucocorticoids and their Receptors
There may be a cumulative effect of social and environmental risk factors which lead to chronic, elevated levels of stress. Constant elevations of maternal stress hormones during pregnancy disrupt developing fetal brain chemistry and architecture, resulting in later memory and learning deficiencies. While we know that the quality of the fetal environment and the timing of exposure to a variety of substances are critical for developmental and health outcomes, little is known about the consequences of maternal cumulative risk on the fetus and later cognitive development. With data from the Nurse Family Partnership Elmira Sample, this work investigates whether maternal cumulative risk during pregnancy predicts IQ in 3 and 4 year olds, without and with postnatal influences. The role that birth outcomes play as mediators of this relationship is also explored. Finally, moderation effects and cumulative genetic risk of five polymorphisms of the glucocorticoid receptor (GR) gene are examined. Increased maternal cumulative risk during pregnancy was negatively associated with IQ at ages 3 and 4 with and without the inclusion of postnatal controls. Birth outcomes partially mediated this relationship to a small extent. GR rs6198 G and rs6190 G alleles infer risk while rs6198 A alleles serve as protective factors with respect to the association of maternal cumulative risk during pregnancy and IQ in young children. This study contributes insights on the cumulative effects of chronic social and environmental stressors that may lead to increased levels of maternal stress hormones during pregnancy and poor cognitive outcomes in young children in the presence of specific glucocorticoid receptor single nucleotide polymorphisms. Application of findings to early intervention programming and policy is discussed.
Developmental psychology, Pregnancy--Complications--Risk factors, Glucocorticoids--Physiological effect, Preschool children--Intelligence levels, Genetics
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