A groundbreaking study published in the British Journal of Psychology found a link between high levels of testosterone in the womb of pregnant women and autistic traits in their children.

The study was prompted by statistics that autism is four times more common in boys than in girls. It is also linked with other traits found more often in boys, such as left-handedness.
The study observed and tested 235 children whose mothers had an amniocentesis during pregnancy over eight years.

Researchers plan to continue studying the children they have been following and will now look for a link between high levels of testosterone in the womb and children who have been diagnosed with autism by studying banks of amniotic fluid that have been collected since 1990 in Denmark.