There’s some alarming news for pregnant women: a new study has found that women who are obese during pregnancy have almost twice the odds of getting a child who has autism than women who aren’t obese.

And if you have diabetes during that pregnancy in addition to being obese, the risk is a stunning four times that of moms who are at a healthy weight, according to a Reuters report.

About one in 68 children are born with autism spectrum disorder (ASD). This can incluse autism, Asperger syndrome, and other developmental disorders. That comes out to a rate of 1.5 percent of children, meaning that obese women have a 3 percent risk and when diabetes is factored in that rises to 5 or 6 percent.

Scientists examined 2,734 mother-child pairs for the survey at Boston Medical Center between 1998 and 2014 and found that 102 of the kids had received an ASD diagnosis. Boys were more likely than girls to have ASD, and the mothers were more likely to be older, obese, and have diabetes.

Maternal obesity was associated with a 92 percent increase in autism risk, and diabetes before pregnancy increased the risk by three times — and when both were the case, the risk was quadrupled and even quintupled if the diabetes was present before conception.

Why is this the case? Scientists aren’t sure, but it could be due to the increased nutrients and hormones from obesity and diabetes, which can impact how the brain develops in the fetus.

The study has huge ramifications because of the problem of obesity and diabetes worldwide, which continues to grow. A third of women in childbearing age are obese, and about one in 10 have diabetes. Of those, between 2 and 10 percent of mothers get diabetes during pregnancy.