On Monday, American researchers revealed that being an older mother manages to significantly increase the risk of having an autistic child, but being an older father, on the other hand, increases this risk only if the mother in below the age of 30.

As per the new research, women who are over the age of 40 face a 50% greater risk of having a child who could be later diagnosed as autistic, as compared to a woman who is between the age groups of 25 to 29.

"The older the mother, the more the risk that the child will develop autism, regardless of whether the father is young or old", said researcher Irva Hertz-Picciotto of the University of California Davis MIND Institute.

For the sake of study, researchers analyzed data collected on 4.9 million births and 12.159 cases of autism from across California, and the findings have come as a contradiction to the 2006 study of Israeli children which stressed that paternal age had a much greater role to play.

Details of the study have been published in the journal Autism Research.