Like many pediatricians, Dani Dumitriu was prepared to respond to the effects of the SARS-CoV-2 coronavirus when it first circulated in her ward. She felt at ease when she was in the hospital for a newborn with COVID-19 illness just born. Understanding the effects of Zika and other viruses that can lead to birth defects means doctors are looking for problems.
But hints of more subtle and insidious trends followed. Dumitriu and her team at New York-Presbyterian Morgan Stanley Children's Hospital in New York City have more than two years of infant development data — they've been analyzing communication and motor skills in 6-month-olds since late 2017. Dumitriu thinks it would be interesting to compare the results of babies born before and during the flu pandemic. She asked her colleague Morgan Firestein to assess whether there were neurodevelopmental differences between the two groups. Morgan Philstein is a postdoctoral fellow at Columbia University in New York.
A few days later, Fellstein panicked and called Dumitriu. "She said, 'We were in crisis and I didn't know what to do because we would not only be affected by the pandemic, but would have a big impact,' Dumitriu recalled. ’”。 She hadn't slept most of that night, carefully studying the data. Babies born during the influenza pandemic scored on the gross motor, fine motor and communication skills tests on a lower average than babies born before the pandemic (both groups of babies were assessed by their parents using established questionnaires). It doesn't matter if their biological parents are infected with the virus; the environment of the pandemic itself seems to be somewhat problematic.
Dumitriu was stunned. "We were like, oh my God," she recalled. "We're talking about hundreds of millions of babies."
Although children infected with SARS-CoV-2 generally perform well, preliminary research suggests that pandemic-related stress during pregnancy may have a negative impact on fetal brain development in some children. In addition, tired parents and caregivers may interact with younger children in different or fewer ways, affecting the child's physical and mental abilities.
The lockdown, which is crucial to controlling the spread of the coronavirus, has isolated many young families, depriving them of playtime and social activities. Stressful and thin, many caregivers are unable to provide the one-on-one time babies and toddlers need.
James Griffin, Director of the Child Development and Behavior Division at the National Institute of Child Health and Human Development at Eunice Kennedy Shriver, Bethesda, Maryland, said, "Everyone wants to document how this affects child development, parent-child relationships and peer relationships. ”。“ Everyone has concerns. ”
Some teams around the world studying these issues are starting to publish their findings. New research has begun. It's hard to find definitive answers, especially since many child development research labs shut down during the pandemic.
Some babies born in the past two years may experience stunting, while other babies may thrive if caregivers stay at home longer and siblings have more opportunities to interact. As with many aspects of health during the pandemic, social and economic disparities have a clear role in who is most affected. Early data suggest that the use of masks did not have a negative impact on children's emotional development. But prenatal stress may cause some changes in brain connections. The situation is evolving, and many studies have not yet gone through peer review.
Some researchers have proposed that many stunted children will be able to catch up without lasting effects. Moriah Thomason, a child and adolescent psychologist at NYU Grossman School of Medicine, said: "I don't think we're going to find a generation hurt by this epidemic. ”
One laboratory remains open during the COVID-19 pandemic, Brown University's advanced infant imaging laboratory in Providence, Rhode Island. In the paper, medical biophysicist Sean Deoni and his colleagues used magnetic resonance imaging (MRI) and other techniques to study how environmental factors affect infant brain development.
While the pandemic has changed the way they conduct research — fewer visitors and more cleaning — they continue to invite infants to their labs to track motor, visual and language skills as part of a seven-year study by the National Institutes of Health on early childhood development and its impact on later health.
However, as the outbreak progressed, Diony began to hear worrying comments from colleagues. Dioni recalls: "Our employees started telling me, 'Man, it's going to take a long time for these kids to pass these assessments.' ’”。
Confused, he asked his researchers to plot and compare the annual mean and variance of the infants' neurodevelopment scores. It was then that they found that the percentage during the influenza pandemic was much worse than in previous years. He said in late 2021: "At the end of last year and at the beginning of this year, everything started to slide off the rocks. "When they compared the participants' results, pandemic-born babies scored nearly two standard deviations lower than babies born before in a series of tests that measured development in a similar way to IQ tests." They also found that infants from low-income households experienced the greatest declines, with boys being more affected than girls and gross motor function the most.
At first, Dioni thought that the choice bias was at work: perhaps the families who struggled to come to be tested during the influenza pandemic were those whose children were at risk of developmental problems or had already demonstrated them. But, over time, he came to believe that choice bias did not explain the findings, because the children who came had no different backgrounds, birth outcomes, or socioeconomic status than previous participants.
These effects may seem severe, but some researchers believe they don't necessarily predict long-term problems. Marion van Den Hevel, a developmental neuropsychologist at Tilburg University in the Netherlands, said: "IQ in infancy does not predict much. ”。“ It's hard to say what this means for their future. She noted that one study3 showed that Romanian girls who started living in orphanages but were adopted by foster families before age 2.5 were less likely to develop mental illness at age 4.5 than girls who remained in institutional care. This situation differs from the pandemic but suggests that once restrictions are lifted, babies can make up for the difficulties.
Worryingly, however, Diony found that the longer the outbreak lasts, the more deficiencies children accumulate. Speaking of the discoveries, Deoni said: "The scale of this discovery is enormous and shocking. The findings are currently being revised by the American Medical Association Journal.
When Deoni first published his findings on Preprint Server 2, there was a series of worrying media coverage — and backlash from the research community. Griffin said: "The real concern is that these results are published without proper peer review. ”。
But assuming that a baby with COVID-19 disease is born with an outcome that does have merit, why do babies experience significant cognitive impairments, especially movement disorders? Dioni suspects that these problems stem from a lack of human interaction. In a follow-up study that has not yet been published, he and his team documented parent-child interactions at home and found that parents have said less to their children (and vice versa) in the past two years than in previous years. He also suspects that babies and toddlers don't do a lot of gross exercise training as usual because they don't often play with other kids or go to the playground. "Unfortunately, these skills lay the groundwork for all the other skills," he said.
Other recent studies also support the idea that a lack of peer interaction may discourage some children. In a study published earlier this year, British researchers surveyed the parents of 189 8-year-olds on January 03, asking whether their children had received daycare or attended kindergarten during the influenza pandemic and assessing language and executive abilities. The authors found that children were more skilled if they received group care during the influenza pandemic, and these benefits were more pronounced in children from low-income backgrounds.
The greatest risks appear to be children of color or low-income families. For example, a growing body of research suggests that distance learning among school-age children may be widening the large learning and development gap that already exists between wealthy and low-income children and between white and colored children. In the Netherlands, the researchers found that in the 2020 national assessment, children from poorer performers and children from less educated families lost up to 60 percent of their learning compared to the previous three years.
In parts of sub-Saharan Africa, including Ethiopia, Kenya, Liberia, Tanzania and Uganda, studies have shown that some children lose up to a full year of schooling. In the United States, after the first lockdown, a report from consulting firm McKinsey showed that students of color were three to five months behind in their fall enrollment, while white students were only one to three months behind.
Masking effect
Children who go to school or participate in other group activities during an influenza pandemic often interact with other people wearing masks. An important question is whether wearing a mask also affects a child's emotional and language development, as masks obscure parts of the face that are important for expressing emotions and language.
Edward Tronick, a psychologist at the University of Massachusetts boston, was bombarded with emails from parents and pediatricians who were concerned about the potential developmental impact of masks. Tronick is best known for his 1975 "Still Life Face" experiment, which showed that when biological parents suddenly stayed face-to-face when interacting with their babies, their children initially tried to get their attention and then slowly withdrew, becoming increasingly frustrated and cautious.
Tennick decided to see if the mask had a similar effect. He conducted an experiment (not yet peer-reviewed) with colleagues, psychologist Nancy Snidman, in which parents used smartphones to record interactions with babies before and after wearing masks. While babies notice when their parents put on their masks — they briefly change their facial expressions, look away or point at the masks — they continue to interact with their parents as before. Tennick said the mask blocked only one communication channel. "The masked parents are still saying, 'I'm talking to you, I'm still waiting for you here, I'm still in touch with you.'" ”
Masks also don't seem to cause much interference with emotional or verbal perception. A study published in May said two-year-olds are still able to understand what adults say wearing opaque masks. Leher Singh, a psychologist at the National University of Singapore, said children "make up for the information deficit more easily than we thought". Researchers in the United States found that although masks make it harder for school-age children to perceive adult emotions — about as difficult as adults do when they wear sunglasses — children are still able to make accurate inferences in most cases.
Madison, a postdoctoral researcher at the University of Wisconsin, said: "Children can use many other clues to distinguish other people's feelings, such as voice expression, body expression, background, etc. ”
Pregnancy and stress
Other researchers are eager to know whether the epidemic affects children's development before birth. Catherine Lebel, a psychologist at the Developmental Neuroimaging Laboratory at the University of Calgary in Canada, surveyed more than 8,000 pregnant women during the pandemic. Nearly half reported symptoms of anxiety, while a third had depressive symptoms — a much higher rate than in previous years of the pandemic. How does this stress affect babies in the womb?
To find out, the researchers used MRI to scan the brains of 75 babies months after birth. In a preprint released in October, they found that babies born to people who reported more prenatal distress (more anxiety or depressive symptoms) showed different structural connections between the amygdala (a brain region involved in emotional processing) and the prefrontal cortex (an area responsible for performing functional skills).
In a previous small study, Lebel and her team looked at the link between prenatal depression and differences in brain connectivity in these areas and proposed that in boys, these brain changes were associated with aggressive and hyperactive behaviors before age 12. Other research teams have found that changes in connectivity between these areas in adults are risk factors for depression and anxiety13. Lebel said: "These are all related areas of emotional processing, and many different behaviors. ”。
Other studies have found a similar link between prenatal pandemic stress and child development. Livio Provenzi, a psychologist at the IrcCS Mundio Foundation in Pavia, Italy, and his colleagues observed that babies as young as three months experience more stress and anxiety during pregnancy, and they have more problems regulating emotions and attention – they are unable to maintain their focus on social stimuli, for example, babies are less likely to be soothed than babies who are less stressed and anxious during pregnancy14.
Thomasson is conducting her own research to assess the effects of maternal stress on children's brains and behaviors. She noted that while there is a lot of concern about how prenatal stress might affect pandemic babies, the early findings don't mean that children will struggle for the rest of their lives. "The children are very adaptable and resilient," she said. We do hope that the situation will improve and that they should be able to adapt to many of the things that are happening. ”
In fact, studies of historical catastrophes have shown that while intrauterine stress can be harmful to babies, there are not always lasting effects. Children born under intense stress from the 2011 Queensland floods in Australia showed deficiencies in problem-solving and social skills at six months of age, while children under less stress showed less than 15. By 30 months, however, these results are no longer associated with stress, and the more positive the parent response to the needs of infants and toddlers after birth, the better the toddlers perform.
Caution and action
Research on pandemic babies presents a mixed picture, and scientists say it's too early to come up with a meaningful explanation. On the one hand, some of the earlier, often unpublished findings may not reflect reality, says Catherine Monk, a medical psychologist who works with Dimitri of the New York-Presbyterian Church.
For example, parents who choose to participate in some of the earlier studies may not be a representative sample, Munch said. Maybe they're already worried about their kids because of the behavior they see. In addition, she said, wearing a mask could affect the results of individual studies like Deoni's — potentially small but enough to distort the results.
As Thomasson said in a review 17 in the Journal of the American Medical Association last year, the motivation for publishing interesting findings may have also influenced these early studies. "Scientists will soon go looking for a harmful difference," she said. It will get the attention of the media; it will be published in a high-impact magazine. ”
Researchers and funders are conducting large studies and collaborations to help build a clearer picture. The National Institute on Drug Abuse has funded a number of studies through its Healthy Brain and Child Development Research. These studies will look at how maternal stress and substance use affect children's development during the pandemic. In addition, alliances and conferences have been formed to bring researchers together to share emerging data. In March 2020, Thomasson launched the International Consortium for the Study of the Coronavirus Generation, which brings together researchers from 14 countries to study families with young children during the pandemic. The consortium held a research summit in November 2021 that included researchers from the northern and southern United States, Europe, Australia, Asia, the Middle East and Africa.
More than 3 million children in the United States test positive for COVID-19
Dumitriu notes that even if a child's brain is really affected by the flu pandemic, there is still time to steer them back on track. "We can all be a public health emergency ahead of schedule," she said. "The brains of six-month-olds are very malleable, we can get into it, we can change their trajectory."
Parents can progress by playing and talking to young children on a regular basis and giving them the opportunity to play with others in a safe environment. Policy changes aimed at supporting families and children may also have an impact. Lebel's study11 found that meaningful social support during pregnancy, such as support from a partner or close friend, greatly reduces prenatal distress. "We can do more in the prenatal care ecosystem," Munch said. The researchers also advocate interventions that support families immediately after birth. Provinci's study14 found that people who had just given birth and were visited by nurses and neonatologists at home felt less stress and anxiety than those who did not.
Overall, the researchers believe that most children may be fine, but at the moment it may be more difficult than usual. If we want to support those who are lagging behind, we had better intervene as soon as possible. Dioni said: "Of course the kids are resilient. ”。“ But at the same time, we also recognize the importance of the top 1,000 Children's lives every day is a crucial early foundation. "So far, the first pandemic babies born in March 2020 have exceeded 650 for several days.
Dioni said children "are a product of the environment." "The more we inspire them, play with them, read for them, love them – that's what we're going to do."