Overview
- Analyzing 18,124 births at Mass General Brigham from March 2020 to May 2021, the study found neurodevelopmental diagnoses by age 3 in 16.3% of children exposed in utero to SARS-CoV-2 versus 9.7% of unexposed peers, reflecting 29% higher adjusted odds.
- Autism diagnoses were more frequent among exposed children, at about 2.7% compared with about 1.1% among children whose mothers did not have Covid-19 in pregnancy.
- Elevated risk signals were stronger for boys and when maternal infection occurred in the third trimester, a period the authors note is critical for brain development.
- Authors and outside experts emphasized that the results show an association rather than causation, that the absolute risk remains low, and that unmeasured factors such as maternal obesity, hypertension, and gestational diabetes could confound findings.
- Because roughly 93% of mothers in the cohort were unvaccinated, experts called for research in vaccinated pregnancies and urged preventive measures to reduce infection during pregnancy.