Testosterone levels in the womb linked to language problems
New research from Perth’s Telethon Institute for Child Health Research has found that boys who are exposed to high levels of testosterone before birth are twice as likely to experience delays in language development.
The research has been published in the latest edition of the international Journal of Child Psychology and Psychiatry.
The study, led by Associate Professor Andrew Whitehouse, used umbilical cord blood to explore the presence of testosterone when the language-related regions of a fetus’ brain are undergoing a critical period of growth.
Dr Whitehouse said the finding is significant in that it gives a biological explanation for why boys language development differs to that in girls.
"An estimated 12% of toddlers experience significant delays in their language development," Dr Whitehouse said.
"While language development varies between individuals, boys tend to develop later and at a slower rate than girls.”"
Dr Whitehouse said the research team wanted to test whether this could be due to prenatal exposure to sex-steroids such as testosterone.
Male fetuses are known to have 10 times the circulating levels of testosterone compared to females. The team proposed that higher levels of exposure to prenatal testosterone may increase the likelihood of language development delays.
Dr Whitehouse’s team measured levels of testosterone in the umbilical cord blood of 767 newborns before examining their language ability at 1, 2 and 3-years of age.
The results showed boys with high levels of testosterone in cord blood were between two-and-three times more likely to experience language delay. However, the opposite effect was found in girls, where high-levels of testosterone in cord blood were associated with a decreased risk of language delay.
Previous smaller studies have explored the link between testosterone levels in amniotic fluid and language development. However, this is the first large population-based study to explore the relationship between 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 Paediatrician,” Dr Whitehouse said.“Potentially, this could help us to identify children at higher risk for language delay at an earlier age, increasing the opportunity for effective therapies. "
Dr Whitehouse heads the Autism Research Team at the Telethon Institute for Child Health Research and is also investigating whether testosterone levels in the womb could be a risk factor for autism.