**Mom’s Stress Hormone Shapes Child’s IQ**
Cortisol’s Impact on Boys
Elevated levels of cortisol, a stress hormone, during the third trimester of pregnancy have been linked to lower IQ scores in 7-year-old boys, according to a study by Odense University Hospital in Denmark. The researchers speculate that boys may be less protected by placental enzymes that convert cortisol into its inactive form, resulting in higher exposure to cortisol in the womb.
Gender Differences
Interestingly, the study found no significant correlation between cortisol levels and IQ scores in girls. This suggests that the enzyme that regulates cortisol exposure may function differently in girls, providing them with more protection from the potential negative effects of cortisol.
Physiological Cortisol
Cortisol is essential for fetal development, but excessive levels during pregnancy can have adverse effects. It is thought to influence cognitive function in children later in life. Pregnant women carrying girls generally secrete more cortisol than those with boys.
Prenatal Exposure
The study analyzed data from 943 pregnant women, measuring their cortisol and cortisone levels during the third trimester. The children’s IQ tests were conducted at age seven. Boys exposed to higher cortisol levels showed lower IQ scores, while girls with higher maternal cortisone levels scored better on IQ tests.
Cognitive Development
Dr. Anja Fenger Dreyer, the lead author of the study, said that “our results show that girls may be more protected by the activity of placental 11β-HSD2, whereas boys may be more vulnerable to prenatal exposure of maternal physiological cortisol.” This suggests that prenatal cortisol exposure may have different effects on the cognitive development of boys and girls.
Future Implications
The findings highlight the importance of managing stress during pregnancy, particularly in the third trimester. Further research is needed to understand the long-term effects of prenatal cortisol exposure and develop strategies to mitigate any potential negative consequences for children’s cognitive development.
Mehek 
Divya