A comparison of obstetric and neonatal complications between children with autistic disorder and their siblings.

Researchers pulled obstetric and newborn hospital records for kids with autism and their brothers or sisters. They scored each record for problems like low birth weight, emergency delivery, or time in intensive care. Then they asked: do autistic children have more of these troubles than their own siblings?

Overall, the two groups looked almost the same. Most birth events and complications did not differ between autistic children and their siblings. Only a small subset of kids with very severe autism showed a link between higher complication scores and greater symptom severity.

The result lines up with Cryan et al. (1996), a direct replication that also found no rise in obstetric adversity when autistic kids were compared to matched controls. It updates the 1980 view from Handleman et al. (1980), which had reported more pregnancy problems in autism; the newer sibling design controls for family background better and washes out that signal.

Later work extends the question. Atladóttir et al. (2015) looked at a wider list of newborn illnesses and saw higher rates in babies later diagnosed with ASD, but the increase was shared with other developmental disorders, not unique to autism. Perales-Marín et al. (2021) went further, showing that different ASD subgroups—defined by added conditions like ADHD or epilepsy—carry their own distinct prenatal risk patterns. Together these papers move the field from 'do birth events cause autism?' to 'which subtypes might be sensitive to which events?'

For BCBAs, this means birth history is rarely useful for deciding whether to assess a child. Focus your intake interview on current behavior, communication, and learning history instead. If you work with a child who has severe autism plus many medical issues, you can expect a slightly rockier health trajectory—plan for extra coordination with nurses or physicians—but routine obstetric data alone should not steer intervention choices.