Children born to mothers who experienced severe stress or depression during or after pregnancy may face a higher risk of autism, according to new research from Japan.

The findings highlight the critical role of maternal mental health in early child development.

The study analyzed data from more than 23,000 mothers and their children, examining how maternal depression affected child development. Researchers found a clear association between maternal mental stress and increased autism-like symptoms in children.

To strengthen the evidence, scientists also conducted biological experiments on mice, which supported the link between maternal stress and developmental changes related to autism.

Autism risk shows gender differences

While boys overall showed more autism-like symptoms regardless of their mother’s mental health, the effects of maternal depression were particularly pronounced in girls. Girls exposed to maternal depression were more likely to be born with low birth weight and showed weaker emotional bonding with their mothers.

The research noted that, across the board, boys exhibited more autism-like traits than girls, independent of whether their mothers experienced depression.

Role of stress hormones

According to the report, mental stress affects levels of oxytocin, a hormone essential for bonding and social behavior. Disruptions in oxytocin may help explain the biological pathway linking maternal depression to autism risk.

Researchers emphasized that screening mothers for mental health issues during pregnancy and after childbirth is crucial. Early identification and support could play a significant role in reducing potential risks for children.

Another study involving more than 140,000 pregnant women found that using antidepressants during the second and third trimesters nearly doubled the risk of autism in children.

These findings have reignited debate around autism diagnosis, particularly the underdiagnosis of autism in girls, and the need to closely monitor mental health treatments during pregnancy.