Males at Greater Than Twice the Risk of Language Delay Than Females
New research by Australian scientists reveals that males who are exposed
to high levels of testosterone before birth are twice as likely to
experience delays in language development compared to females. The
research, published in Journal
of Child Psychology and Psychiatry, focused on 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.
“An estimated 12% of toddlers experience significant delays in their
language development,” said lead author Professor Andrew Whitehouse from
the University of Western Australia. “While language development varies
between individuals, males tend to develop later and at a slower rate
than females.”
The team believed this may 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.
Professor 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 male infants 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 female
infants, 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,” concluded Professor Whitehouse. “Now these findings
can help us to understand the biological mechanisms that may underpin
language delay, as well as language development more generally.”
