High Sex Hormone Levels in Womb Double Risk of Language Delays in Boys
Exposure to high levels of testosterone before birth doubles the risk of experiencing delays language development in boys and decreases risk of language delays in girls, according to new research.
It is estimated that 12 percent of toddlers experience significant delays in language development, and while language development differs between individuals, males generally develop later and at a slower rate than females, Australian scientists said in a released statement Wednesday.
Researchers believe that this may be caused to prenatal exposure to sex-steroids, like the hormone testosterone. Male fetuses have ten times the level of circulating testosterone compared to females, and they found evidence that high-levels of the sex hormone in cord blood is linked with a significant increase in the likelihood of language development delays.
Professor Andrew Whitehouse from the University of Western Australia and his team measured the testosterone in the umbilical cord blood of 767 newborns before examining their language ability at 1, 2 and 3-years of age.
Researchers found that male infants with high levels of testosterone in their umbilical cord blood were two to three times more likely to experience language delay, but the opposite effect was found in female infants, where high-levels of testosterone were actually associated with a decreased risk of language delay.
Previous research has also demonstrated the relationship between the sex hormone and language delays by testing levels of testosterone in the amniotic fluid, and researchers said that this was the first study to explore the link based on measurements from the umbilical cord blood and language delay in the first three years of life.
"Language delay is one of the most common reasons children are taken to a pediatrician," said Whitehouse. "Now these findings can help us to understand the biological mechanisms that may underpin language delay, as well as language development more generally."
The study findings are published in the Journal of Child Psychology and Psychiatry.