Children whose mothers who are exposed to severe or moderate stress during pregnancy may have long term effects on their intellectual development. Previous studies have shown that significant stress during pregnancy may affect fetal growth and development, but little is known about whether this has long-term effects on children's cognitive functioning. Researchers from Canada studied 89 children, up to 5 years of age, whose mothers had gone through severe to moderate stress during their pregnancy. They assessed the intelligence quotient (IQ) and vocabulary of the children of these mothers. Mothers were given questionnaires to know about the extent of objective stress and subjective distress they faced during pregnancy. They were also assessed for psychological functioning. It was found that children exposed to severe levels of objective stress had lower overall IQ, verbal IQ and language abilities, compared to the children exposed to moderate or low level of prenatal maternal stress. However, there were no effects of subjective and objective stress on the performance IQ. Researchers noted that all the children were within the normal range for intelligence and language development. However, the findings suggest that prenatal stress might have lingering effects on children's brain structures, particularly those involved in language and verbal abilities. Prenatal exposure to a moderately severe stress is associated with lower cognitive and language abilities at 5 years of age. However, it is not clear exactly why serious prenatal stress would affect children's intellectual development. Therefore, further studies are needed to confirm the same.
Journal of American Academy of Child and Adolescent Psychiatry
September 2008