Does COVID-19 during pregnancy lead to neurodevelopmental problems in babies?

Researchers are still trying to discern whether a COVID-19 infection during pregnancy can lead to long-term problems for the child.

Some studies find no difference between babies born to mothers infected during pregnancy, while one recent study found an increased risk for neurodevelopmental delays in boys exposed to the virus while in utero.

That study found that boys, but not girls, born to mothers who had a positive PCR test during pregnancy were more likely to receive a neurodevelopmental-related diagnosis within their first year of life. It was published last month in the Journal of the American Medical Association Network Open.

Meanwhile, another recent study also published in JAMA found no relationship between in-utero COVID-19 exposure and brain development in children.

Authors of both studies and outside experts say the conflicting data shows longer-term studies are needed to fully understand if and how COVID-19 in pregnant people affects infant neurodevelopment. Research that measures milestones across early childhood and beyond is needed to fully assess whether or not there is a risk.

While right now it’s not fully known whether COVID-19 causes neurodevelopmental problems, it has long been known that an infection during pregnancy puts children at higher risk for conditions like autism, attention-deficit/hyperactivity disorder and schizophrenia years later, with some research showing boys, in particular, are more vulnerable.

"There is growing evidence linking prenatal maternal infection and inflammation and risk for later neurodevelopmental disorders like ADHD, schizophrenia," said maternal-infant health expert Catherine Limperopoulos, who wasn't involved in either study.

Limperopoulos, who directs the Developing Brain Institute at Children's National Hospital, noted that both analyses only studied babies prior to when many milestones in expression, cognitive function and others typically emerge.

The fetal brain is particularly vulnerable to prenatal exposures, she said, including any infection during pregnancy, which may predispose children to neuropsychiatric diseases.

Still, "the data is still conflicting, and long-term studies are needed," she said. "The good news is that to date, it appears that developmental concerns – if present – are mild."

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Study finds neurodevelopmental risk in baby boys: What to know

In last month's analysis, researchers studied electronic health records of more than 18,000 births in Massachusetts. These babies were born between March 2020 and May 2021 and a couple of years before the pandemic, for comparison.

Male infants were 90% more likely to have a neurodevelopmental diagnosis, such as motor function or psychological development, at 12 months of age compared to infants who were born to moms without a COVID-19 diagnosis. Female babies didn't have the same risk.

“The results really resonated with what is biologically plausible because we know that male children have an increased risk for neurodevelopmental diagnoses like autism, or ADHD, or cognitive dysfunction compared to female children,” said lead author Dr. Andrea Edlow, a maternal-fetal medicine specialist at Massachusetts General Hospital. “We also know that male fetuses are more vulnerable to injury from intrauterine exposures that can cause a variety of outcomes.”

The diagnoses could be due to “downstream effects” from the mother’s immune system fighting the virus, such as inflammation.

It's important to note that any potential effects from in-utero exposure to COVID-19 "may take years to manifest," said Limperopoulos. "As such, long-term studies are critical to track the developmental progress of these infants to better understand their developmental trajectories over time."

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Other study finds no effect on babies

Researchers in last week's analysis studied around 400 babies born in three hospital systems in New York, Utah and Arkansas between March 2021 and June 2022. They found no difference between babies born to mothers infected who had the virus and those who didn’t.

While smaller, the study included babies from more than one state, and the research group used the Developmental Assessment of Young Children to assess the babies' neurodevelopmental progress, while the previous study collected that data through diagnoses marked in health records.

“Our evidence of a negative result is really reassuring,” said lead author Dr. Dani Dumitriu, a newborn hospitalist and neuroscientist at Columbia University.

The babies were enrolled in two ongoing studies tracking COVID-19 and mother-and-baby outcomes led by Dumitriu.

Last year, a meta-analysis of eight studies and more than 21,000 infants also found that overall neurodevelopment wasn’t changed by birth during the pandemic or gestational exposure, except for communication delay.

The bottom line: What parents should know

If a parent is concerned after contracting COVID-19 infection during pregnancy, experts say they should talk with their pediatrician about developmental evaluations.

"Pregnant people can protect their babies by ensuring that they attend their well-baby visits with their pediatricians so that their development milestones are monitored over time," Limperopoulos said.

Mothers, those expecting, breastfeeding and trying to get pregnant should protect themselves against COVID-19 by getting vaccinated, and experts say the shot is safe for pregnant people.

Pregnant people are more vulnerable to adverse health outcomes if they contract COVID-19, according to the CDC. Data from the agency shows an upward trend among pregnant patients receiving the vaccine.

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Reach Nada Hassanein at nhassanein@usatoday.com or on Twitter @nhassanein_.

This article originally appeared on USA TODAY: COVID during pregnancy: Does it affect baby brain development?