The study, based on a survey of 326 families in Washington and Oregon, found that slightly more than half the women worked fewer hours to accommodate the needs of their child and three out of five had not taken a job because of their child's autism. To care for the child, one-quarter had taken a leave of absence and nearly as many had not taken a promotion. Nearly 60 percent had suffered financial problems in the past year.

In two-parent households, two-thirds of the parents said the mother's work outside the home was most affected by their child's autism.

"We found that negative effects concentrate on the mother," said Dana Baker, lead author with Laurie Drapela of a paper published online this month in the peer-reviewed Social Science Journal.

Frequently, Baker says, mothers of autistic children must deal with extra doctor's appointments, conflicts at daycare, and meetings with teachers on Individual Education Plans -- "things an employer could work around. Instead the mother gets reprimanded at work and that causes additional stress."