Babies conceived through IVF may be twice as likely to develop autism , according to new research . Children conceived using assisted reproductive technology were more likely to develop autism than babies conceived naturally . Assisted reproductive technology ( ART ) includes any type of fertility treatment where the egg and the sperm are handled outside of the body , including IVF , artificial insemination and surrogacy . During IVF - the most popular ART treatment - more than one egg is harvested and fertilised , which can lead to multiple births . Babies conceived through IVF ( pictured ) are more likely to develop autism than those conceived naturally , a study found . But this could be due to the complications of IVF , such as multiple births . Researchers explained they found an association between IVF and autism - but they did not prove that the treatment cause the disorder , according to HealthDay news . The higher risk of the disorder could be explained by factors such as multiple births and other risks associated with IVF , not the treatment itself , they said . After taking into account factors such as the mother 's education and multiple births , researchers found the increased risk was only seen for mothers under 35 years old . And they found there was no extra risk of autism for women who gave birth to one child . This means IVF using a single-egg transfer rather than multiple eggs lowers the chance of a baby developing autism , experts said . The study involved nearly six million children born from 1997 to 2007 . The team , led by Peter Bearman , a professor of social sciences at Columbia University in New York City , collected data on 5.9 million California births , including 48,865 infants conceived through assisted reproduction , and 32,922 children with autism . Autism is mainly caused by a child ’ s genes , a major study of British twins has found . Scientists said that , in the average boy or girl with autism , genetics explain up to 98 per cent of the illness . The research , by King ’ s College London , found the condition is highly inheritable . Controversial research linking autism with the MMR jab has been widely discredited , but more recent concern has focused on the condition being fuelled by environmental factors such as pollution . With cases of autism much more common today than in the past , many fear it is also being caused by modern lifestyles . But the researchers said their study suggested that lifestyle and environmental factors were a distant second to genetics . They compared the incidence of autism in births that involved advanced infertility treatment such as IVF and those that did n't . Professor Bearman said this was the largest study looking at this relationship that has ever been carried out . The results are not a condemnation of IVF technology , as the study did not prove a cause-and-effect link , he said . He added : 'There is an association between IVF and autism , but when we control for the characteristics of women who are more likely to use IVF , for example , age and social status , this association is lessened significantly , ' The remaining increased risk is due to factors such as multiple births and complications of pregnancy and delivery associated with IVF , he said . He added that there was no significant increased risk of the disorder for children of women who gave birth to one child . He said : 'Knowing that one can largely reduce the risk of autism by restricting the procedure to single-egg transfer is important for women who can then make better informed decisions . ' The research was published online in the American Journal of Public Health . The news comes after a major study published this week found genetics are the main cause of a child 's autism , not lifestyle . Scientists from King 's College London said that , in the average boy or girl with autism , genetics explain up to 98 per cent of the illness . Controversial research linking autism with the MMR jab has been widely discredited , but more recent concern has focused on the condition being fuelled by environmental factors such as pollution . Autism is mainly caused by a child ’ s genes , rather than lifestyle factors , a study published this month found .
Children conceived using infertility treatments were more likely to develop autism than children conceived naturally , Columbia University study found . These treatments include IVF , artificial insemination and surrogacy . Experts : Study shows a link - but does not prove - that IVF causes autism . Higher risk could be explained by complications of IVF , like multiple births . Comment: