MONDAY, March 27, 2023 (HealthDay News) -- Boys born to women who had COVID-19 during pregnancy may be at risk for developmental delays, a new study suggests.
Delays in speech and motor function were the most commonly diagnosed conditions in these children at 12 months. They were seen in boys but not in girls, the study authors said.
"These findings suggest that male offspring exposed to SARS-CoV-2 in utero may be at increased risk for neurodevelopmental disorders," said lead researcher Dr. Andrea Edlow. She is an associate professor of obstetrics, gynecology and reproductive biology at Harvard Medical School, in Boston.
However, she added, "The motor and speech delays noted in our study do not, per se, reveal anything about risk for autism, ADHD [attention-deficit/hyperactivity disorder], or other diagnoses, which are made later in life. Our study cannot yet answer those questions, and only points to the need for longer-term follow-up of these children, given that increased neurodevelopmental risk has already been noted."
It's not uncommon that infections during pregnancy affect infants, Edlow pointed out.
"Multiple viral and bacterial infections in pregnancy have been associated with increased risk for neurodevelopmental diagnoses in offspring. The common thread is maternal immune activation during infection in pregnancy, rather than a specific pathogen," she explained.
As to why boys but not girls are affected, Edlow said that is also seen with other infections.
"Boys are known to be both more vulnerable to neurodevelopmental diagnoses and more likely to have adverse responses to in-utero exposures," she noted. In 2021, Edlow published a study that showed sex differences in placental immune responses to SARS-CoV-2 infection.
This new study stated that it is not clear that changes found at 12 and 18 months are indicators of persistent risks for disorders such as autism spectrum disorder, intellectual disability or schizophrenia.
Whether the severity of COVID-19 affects the risk for developmental delays also isn't clear as researchers didn't look at that specifically, she added.
"It's most important for pregnant individuals to be vaccinated to prevent severe COVID-19 disease, hospitalization and death," Edlow said. "Complications of severe disease are also associated with an increased risk of preterm birth, which itself is a risk factor for adverse neurodevelopmental outcomes, so that is another reason to be vaccinated to try to prevent severe disease."
And recent studies have shown that vaccination during pregnancy can provide protection against hospitalization for COVID-19 in infants up to 6 months of age.
"However, we were not able to specifically examine in this current paper whether maternal vaccination was associated with reduced risk of adverse neurodevelopmental outcomes in offspring," Edlow said.
She said it will be important to follow these children over the long term and to study additional large groups to better understand the potential risks.
For the study, Edlow and her colleagues collected data on more than 18,300 babies born during the pandemic.
About 880 of their mothers had COVID-19 during pregnancy. In all, 3% of their babies were diagnosed with neurodevelopmental delays at 12 months, compared with 2% of kids who were not exposed to COVID-19.
All of the children with neurodevelopmental delays were boys. They had trouble with expressive language, as well as motor issues and what the study described as unspecified psychological disorders. Typical motor skill milestones include crawling, walking and throwing a ball.
By 18 months, the effects were more modest. Boys exposed to COVID-19 in the womb had 42% higher odds of a neurodevelopmental diagnosis at this age, Edlow said.
Dr. Matthew Blitz, a maternal-fetal medicine expert at Northwell Health in Bay Shore, N.Y., reviewed the findings.
"This study emphasizes that there's still a lot we don't know about differences between boys and girls," he said.
For example, Blitz noted that when it comes to preterm birth, boys don't fare as well as girls.
"Some of the thought is that somehow that's related to male growth requirements being higher and more stress in the placenta," he said.
"Particularly with COVID there's still a lot that we don't know in terms of long-term neurodevelopmental outcomes," Blitz added.
He said pregnant women should take steps to avoid getting COVID-19.
"We tell patients to take prenatal vitamins, we tell many patients to take aspirin to reduce the risk of preeclampsia — a lot of different things to reduce risks — and vaccination for COVID is absolutely one of the things that's very important for both moms and for babies for both short- and for long-term outcomes," Blitz said.
The findings were published online March 23 in JAMA Network Open.
For more on COVID-19 and pregnancy, visit the U.S. National Institutes of Health.
SOURCES: Andrea Edlow, MD, associate professor, obstetrics, gynecology and reproductive biology, Harvard Medical School, Boston, and maternal-fetal medicine specialist, Massachusetts General Hospital, Boston; Matthew Blitz, MD, maternal-fetal medicine, Northwell Health, Bay Shore, N.Y.; JAMA Network Open, March 23, 2023, online