Washington [US], May 20 : High levels of the stress hormone cortisol during the third trimester of pregnancy may boost speech and language abilities in the first three years of a child's life, according to research presented at the 25th European Congress of Endocrinology in Istanbul. The findings help us understand how cortisol influences foetal and newborn development.
Early language development is an excellent predictor of how well a newborn's neural system developed in the womb. Prenatal exposure to cortisol, a steroid hormone that assists the body in reacting to stress, controls foetal growth and influences brain development. However, it is still unknown how cortisol influences early language development.
Odense University Hospital researchers reviewed data from the Odense Child Cohort on 1,093 Danish toddlers aged 12-37 months, as well as cortisol levels in 1,093 Danish women during their third trimester of pregnancy. They observed that, whereas females comprehended more words between the ages of 12 and 21 months, boys exposed to high cortisol levels in the womb could speak more syllables between the ages of 12 and 37 months.
"To our knowledge, this is the first study to investigate the association between maternal cortisol levels and language development in children over time, also taking offspring sex and maternal educational level into account," said Dr Anja Fenger Dreyer, who was involved in the study.
She added: "We have had access to a large study cohort, high-quality methods of analysis and relevant covariates, making our study an important contribution to the physiological understanding of prenatal cortisol exposure in fetal maturation and child development."
The team will next assess whether children exposed to high cortisol in the womb are more likely to have higher intelligence quotient (IQ) scores. Except for the data on maternal cortisol levels and early language development, the Odense Child Cohort also has data on intelligence tests carried out by children aged 7.
"Early language development in children is known as a predictor for a cognitive function later in life, such as attention, memory and learning, so we want to investigate whether prenatal cortisol exposure is also associated with IQ scores of children aged 7 years old," said Dr Fenger Dreyer.