Scientists have found one more reason that pregnancy and obesity can be a bad combination.

A new study in the journal Pediatrics suggests that moms who are obese or have diabetes are more likely to have a child with autism or another developmental problem.

The finding is "worrisome in light of this rather striking epidemic of obesity" in the U.S., says Irva Hertz-Picciotto from the MIND Institute at the University of California, Davis, one of the study's authors.

But it's not clear whether there's any connection between rising obesity rates and the increasing number of children diagnosed with autism, she says.

The new study looked at about 1,000 mothers. Half of them had a child with an autism spectrum disorder, while the rest had a child with a developmental delay unrelated to autism, or no developmental problem.