Is COVID in pregnancy linked to infant development issues?

Babies born to mothers who contracted COVID-19 during seem to be at slightly higher risk of neurodevelopmental delays, say US researchers, although they caution their findings are preliminary.

Their retrospective study looked at more than 7,500 infants delivered during the pandemic, including 222 born to mothers with a positive COVID-19 test during pregnancy.

The findings suggest there were differences between infants between the two groups at 12 months, with 14 infants in the COVID-positive group (6.3%) getting a neurodevelopmental diagnosis within that period, compared to 227 of 7,550 controls (3.0%).

The association between infection and subsequent problems – mainly with motor function or speech and language – was greatest in babies born to mothers who were diagnosed with COVID-19 in the last trimester of pregnancy, according to the scientists, who have published their study in the journal JAMA Network Open.

The team, led by Andrea Edlow of Harvard Medical School and Massachusetts Medical Hospital, acknowledge that there is still a lot of research to do in this area, not least because children born to women infected in the first wave of the pandemic are still younger than 2 years of age, when diagnoses of neurodevelopmental issues become more reliable.

"Our results must be recognised as preliminary given the limited duration of follow-up," they write.

Other commentators have also cautioned against early interpretation of the data, saying there remains no evidence of a causative link between COVID-19 and the findings.

Dorothy Bishop, professor of developmental neuropsychology at Oxford University, says that it is hard to accurately diagnose disorders in such young children.

Meanwhile her colleague Marian Knight, a professor of maternal and child population health at the university, points out that it is more likely for instance that pregnant women who have complications would have been tested for COVID-19 in the first place, and there is limited information in the study on complication rates.

"Differences in incidence of other pregnancy complications may explain their results, rather than SARS-CoV-2 infection," she suggests.

"It is equally, if not more, likely that the women in these cohorts who tested positive also have some characteristics associated with later problems in their offspring, independent of COVID-19," according to Dimitrios Siassakos, an obstetrics and gynaecology expert at University College London (UCL).

"For example, whereas the jury is still out whether COVID-19 can harm babies directly, we know for certain that diabetes in pregnancy does, particularly if not diagnosed and treated," he added. "It is possible that un-diagnosed diabetes is the hidden culprit; it could mean women in these cohorts studied are more likely to test positive for COVID, and to have babies with later problems."

Meanwhile, a small Spanish study in 42 mothers and newborns has also found evidence of neurodevelopmental delays at six weeks of age, according to lead investigator Dr Rosa Ayesa Arriola, a neuropsychologist at the Valdecilla Research Institute (IDIVAL) in Santander.

Specifically, babies born to mothers who had been infected showed greater difficulties in relaxing and adapting their bodies when being held, compared to infants from non-infected mothers, with the impact more pronounced if the infection took place in the last trimester of pregnancy.

The analyses were carried out using the Neonatal Behavioural Assessment Scale (NBAS), and in plain terms mean the babies react slightly differently to being held or cuddled, according to Águeda Castro Quinta from the University of Barcelona, one of the study investigators.

The results come from the first group out of a larger cohort of 100 mothers and babies, which will be followed up in the coming weeks and months. The larger group will also be compared to another study population – the epi-project – which is investigating the effect of stress and genetics on a child's neurodevelopment.

"Not all babies born to mothers infected with COVID show neurodevelopmental differences, but our data shows that their risk is increased in comparison to those not exposed to COVID in the womb," said Ayesa Arriola whilst presenting the results at the European Congress of Psychiatry.

"We need a bigger study to confirm the exact extent of the difference."