Overview
- Reviewing 18,124 births at Mass General Brigham (March 2020–May 2021), researchers found 16.3% of children exposed in utero received a neurodevelopmental diagnosis by age 3 versus 9.7% unexposed, a 29% higher adjusted odds.
- Autism was diagnosed in about 2.7% of exposed children compared with about 1.1% of unexposed peers, according to the paper in Obstetrics & Gynecology.
- Elevated risks were concentrated in boys and when maternal infection occurred in the third trimester, a period the authors note is critical for brain development.
- Investigators stress the study is observational and not proof of causation, and they emphasize that the absolute risk for any one child remains low.
- Outside experts and the authors call for replication and vaccinated‑era studies, highlight potential confounding from unmeasured maternal conditions, and urge prevention of infection during pregnancy including vaccination.