Too little — or too much — of certain substances during pregnancy may increase the odds of having a child with autism. Here we explain what scientists know about these associations.

Women who receive epidural anesthesia during labor have an elevated chance of having a child with autism, a new study has found. But it is too soon for doctors to recommend against epidurals, experts say.

High blood pressure during pregnancy may raise a woman’s chances of having an autistic child.

Pregnant women’s use of acetaminophen may increase the odds of autism and attention deficit hyperactivity disorder in their children.

A child’s risk of autism is slightly elevated if a parent or sibling has asthma or an autoimmune disease.

A cell atlas and a cell-culture method promise to advance scientists’ understanding of the placenta and its effects on a fetus.

Chronic exposure to inflammation in the womb alters autism gene expression and disrupts social behavior in male mice, but not females.

Autism results from an interplay between genetics and the environment, but it has been tough to nail down the environmental factors involved.

Women whose children are severely autistic have lower serotonin levels than do those whose children have mild or moderate autism traits.