More than two-thirds of toddlers flagged for autism do not get assessed for the condition by specialists.

Heart-rate patterns and changes in pupil size may herald Rett syndrome, autism or related conditions.

Most regions in the United States do not have an autism diagnostic center or specialist.

Clinical trials of autism treatments rarely use a consistent set of tools to measure efficacy, making it tough to compare the treatments.

As prenatal testing improves, it presents a host of thorny issues — from what to test and how to interpret the results, to what to do about them.

Researchers at the University of Waterloo in Ontario, Canada, have developed a new autism detection technique that distinguishes among different eye-gaze patterns to help doctors more quickly and accurately detect autism in children.

A blood test can accurately detect whether a fetus carries large mutations of the kind linked to autism, according to pilot-study results.

A saliva test that helps clinicians diagnose autism is expected to be available in the next few weeks. But some experts are skeptical of the test’s accuracy and value.

Less than 1 percent of young children in northern Vietnam have autism, but this prevalence is higher than in previous reports.

Autism’s prevalence in Northern Ireland is climbing, but government policies leave families unable to access the treatments they need.