A major Massachusetts study links covid-19 infection during pregnancy to higher risks of autism and developmental delays in children, emphasizing the importance of vaccination for expectant mothers
A new study published in the journal Obstetrics and Gynecology analyzed more than 18,100 births in Massachusetts and found that children born to mothers infected with covid-19 during pregnancy faced a higher risk of autism and other neurological differences, including delays in speech and motor development.
The research, one of the largest of its kind, examined children born to women who contracted the virus between early 2020 and mid-2021, before covid-19 vaccines were widely available.
Study Highlights Association, Not Causation
The study’s authors emphasized that, as an observational study, the findings do not prove that covid-19 causes autism or other developmental conditions, but rather indicate an association between maternal infection and these outcomes.
“It’s not that every pregnant woman with covid-19 in pregnancy needs to think that her child is going to have autism,” said Andrea G. Edlow, a physician scientist at Mass General Hospital and associate professor at Harvard Medical School. “Overall, the absolute risk is not extremely high.”
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Public Health Experts Emphasize Vaccination Importance
Public health experts said the findings underscore the importance of covid-19 vaccination during pregnancy, noting that protecting expectant mothers helps safeguard both their health and that of their babies.
The results come as coronavirus vaccination rates have declined. Earlier this year, Health Secretary Robert F. Kennedy Jr. announced that the CDC would no longer recommend the coronavirus vaccine for healthy pregnant women, prompting widespread criticism from public health experts.
The American College of Obstetricians and Gynecologists continues to recommend vaccination, and federal officials now advise that all Americans, regardless of risk factors, should consult a medical provider about getting a covid-19 vaccine.
Study Examines Over 18,000 Births in Massachusetts
Researchers examined medical records between March 1, 2020, and May 31, 2021. Among 861 women who had tested positive for covid-19 during pregnancy, 140 gave birth to a child who would receive a neurodevelopment diagnosis by age three.
Few had received vaccinations, researchers noted. The study’s co-authors, Edlow and Roy H. Perlis, a Mass General researcher and Harvard psychiatry professor, said future studies of larger populations are needed to assess the potential risk for women who were vaccinated.
Building on Previous Research About Viruses and Fetal Health
The findings build on a growing body of research examining the impact of viral infections on fetal development. There is strong evidence that viruses such as rubella, varicella-zoster, and Zika can directly cause fetal injury.
In 2015 and 2016, the World Health Organization declared a public health emergency when the Zika virus outbreak in Latin America was linked to hundreds of babies born with microcephaly, a condition marked by an abnormally small head and underdeveloped brain.
Scientists believe that respiratory viruses like flu and SARS-CoV-2, which causes covid-19, rarely cross the placental barrier. The impact on the fetus may instead come from the mother’s immune response, particularly inflammation that can influence how neurons grow, connect, and migrate in the developing brain.
Possible Biological Mechanisms Behind the Findings
According to Edlow, “if the fetus’s immune system gets really revved up, that could have downstream consequences, not just for the developing brain, but also for the metabolic system, the liver, the pancreas, the heart, the adipose tissue.”
She added that such effects could potentially lead to obesity, metabolic syndrome, or insulin resistance later in life.
Previous studies have shown that flu and covid-19 are associated with obstetric complications such as preterm birth. However, evidence on long-term effects on children’s neurodevelopment has been mixed, with some studies showing small increases in diagnoses and others finding no significant impact.
Experts Call for Further Research
Mary Ann Comunale, associate professor at Drexel University’s College of Medicine, said the Massachusetts study provides “important evidence-based information for discussion between a clinician and their patient.”
“This is particularly important in the current climate of vaccine hesitancy,” she added.
Lisa Croen, senior research scientist at Kaiser Permanente Northern California, pointed out that maternal conditions such as obesity, hypertension, and gestational diabetes were not controlled for in the analyses, which could have affected results.
She said that while more research is needed, the findings “provide additional, strong rationale for supporting covid-19 vaccination in pregnancy.”
Source: Obstetrics and Gynecology Journal via The Washington Post
