TAMPA, Fla. (WFLA) — About 3% of infants born to mothers who contracted COVID-19 were more at risk of developing neurological issues in the first year after being born, according to a study by medical researchers at Massachusetts General Hospital in Boston, Mass.

The study examined mothers and infants from two hospital systems in six hospitals, with almost 8,000 pairs.

Of the 7,772 mother-infant pairs studied, 222 showed signs that COVID-19 infection during pregnancy led to a higher risk of neurodevelopmental problems in the first year of life. Additionally, the study found that COVID-19 infection while pregnant contributed to the rate of preterm births.

“Preterm delivery was more likely among exposed mothers,” the study said. “Maternal SARS-CoV-2 positivity during pregnancy was associated with greater rate of neurodevelopmental diagnoses in adjusted models.”

The study found the neurodevelopmental risks were “of larger magnitude” in mothers who were infected with COVID-19 in their third trimesters.

The effect of COVID-19 on developing fetal brains could be due to “inflammation and altered cytokine expression during key developmental windows,” the study said. Cytokine expression is a process that occurs when the body responds to injury or infection, causing inflammation. The study said that maternal infection, for COVID-19 and the flue, can affect fetal development.

“Regardless of mechanism, epidemiologic studies demonstrate that maternal infection in pregnancy, including other viral infections such as influenza, is associated with adverse neurodevelopmental outcomes in offspring, including autism spectrum disorders, schizophrenia, cerebral palsy, cognitive dysfunction, bipolar disorder, and anxiety and depression,” the study said.

However, the authors of the study also noted that many of the disorders listed as a potential result of infection in the womb “may not manifest until adolescence or adulthood,” making the risk to children and adults unknown for multiple years, sometimes decades.

Preterm birth can also contribute to some of these conditions. The study said evidence was “emerging” that COVID-19 could lead to preterm delivery and other birth complications, with “a recent report indicating greater severity of infection was associated with greater preterm risk.”

In the cohort studied for the effect of COVID-19 on pregnancy and newborns, the study found the risk of preterm delivery was 14.4% higher for mothers who were COVID-19 positive while pregnant. Even adjusting to effects of preterm birth, the study found preterm birth alone “did not account for all of the observed increased risk of incurring a neurodevelopmental diagnosis.”

Simply put, maternal COVID-19 infections increased the risk of both preterm birth and neurological conditions in newborns, regardless of other health symptoms that could be caused by early delivery, according to the study. However, the study also noted that the symptoms caused by COVID-19 are also caused by other viral infections during maternity, meaning it may not be isolated to COVID-19 alone.

The study was also described by its authors as preliminary. They are working to continue their research with follow-up studies to understand more of the potential effects and health outcomes for in-utero exposure to COVID-19.