A preliminary study of thousands of children born during the pandemic has found that those whose mothers tested positive for COVID-19 during pregnancy were at increased risk of being diagnosed with a developmental disability in the first 12 months of life.
A team led by Roy H. Perlis, MDMSc., 2006 and 2001 BBRF Young Investigator at Massachusetts General Hospital, used electronic health records of births at six Massachusetts hospitals between March 2020 (just after the pandemic began) and September 2020. The records recorded 7,772 live births from 7,466 women, 222 of whom tested positive for COVID-19 during their pregnancy.
The mean mothers were in their early 30s and included women who identified as Hispanic (15%), Asian (10%), Black (8.4%), and White (69%). Overall, 6.3% or 14 of the 222 offspring whose mothers tested positive for COVID during pregnancy were diagnosed with a neurodevelopmental disorder at 12 months of age. This compares to 3% or 227 children out of 7550 born to mothers who did not test positive for COVID during pregnancy.
A wealth of data from epidemiological studies over the years has shown that maternal infection during pregnancy, including viral infection due to influenza, is associated with adverse neurodevelopmental outcomes in the offspring. Risks for a variety of conditions (autism spectrum disorder, schizophrenia, cerebral palsy, cognitive dysfunction, bipolar disorder, anxiety, and depression) are thought to be increased to varying degrees, depending on a number of variables, including the severity of the Infection and possible comorbid diseases of the mother.
While most of these disorders take years to become apparent in a young person, some – including various types of cognitive dysfunction – can be detected in the early years of life. While the 12-month milestone is usually too early to spot autism spectrum disorders, for example, pre-developmental signs are viewed by some as an indication of an increased risk in a child. The ones in the study by Dr. The developmental diagnoses registered by Perlis and colleagues were mostly motor and speech disorders.
The association between maternal infection during pregnancy and increased neurodevelopmental risk in the child is believed to be due to inflammation caused by the maternal infection. Fetal brain development can be affected by the mother’s immune response to inflammation that can be transmitted across the placenta.
New evidence, according to Dr. Perlis, are already suggesting that COVID-19 infection could be associated with preterm birth and possibly other birth complications. However, all studies specifically related to COVID, including our own, must be considered preliminary as children born to mothers who were infected at the start of the pandemic are still only as young as 3 years old. Data on the in the study by Dr. Perlis and colleagues also cannot tell about different risk levels that may correspond to maternal infection by one of the newer COVID variant strains.
Among the results of the current study, it was clear that COVID infection during pregnancy is most likely to increase the child’s neurodevelopmental risk if the infection occurred in the 3rd trimester of pregnancy; and that mothers with COVID infection had significantly more preterm births (14.4% vs. 8.7%).
Because all preterm infants collectively have a higher neurodevelopmental risk than full-term infants, it was important for the team to quantify the increased neurodevelopmental risk in children born to infected mothers who gave birth as planned. After accounting for preterm birth, children born to infected mothers were still 86% more likely to have a neurological diagnosis, suggesting that the association between COVID infection during pregnancy and the child’s neurodevelopmental risk is not just a consequence of more preterm births .
The team of dr. Perlis and a commenter in the journal in which the study was published JAMA network opennoted that the results of this study were not designed to demonstrate a causal relationship between maternal COVID infection and the child’s neurodevelopmental risk, only an association.
This is one of the reasons the team is calling on the research community to conduct larger and longer-lasting follow-up studies examining the effects of COVID infection during pregnancy on mothers and their children.