CDC study shows COVID-19 in newborns is rare

By Colin Lightfoot, M.Sc. Infection and ImmunityNov 9 2021

To date, there have been relatively few cases of neonates with COVID-19, and there is limited knowledge of neonatal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, recent studies have suggested an increased risk of severe COVID-19 in infants compared to older children, which is based on data that shows an increased rate of hospitalization among infants.

Study: Illness severity indicators in newborns by COVID-19 status in the United States, March–December 2020. Image Credit: Daniel Catrihual / Shutterstock

In the US, between February and April 2020, infants less than one-year-old accounted for 62% of all pediatric COVID-19-related hospitalizations, and infants less than three months of age accounted for 18.8% of pediatric COVID-19-related hospitalizations between March and July 2020. However, clinicians may be more inclined to admit neonates with COVID-19, so the hospitalization rate may not be appropriate for determining disease severity.

Evidence from previous research suggests that there is a low incidence of COVID-19 among neonates, and when disease does occur, it is relatively mild, though cases of severe disease have been reported. For example, a French study revealed that 37% of all pediatric COVID-19 hospital admissions were of children younger than ninety days, however, 97% of these infants did not experience severe disease.

Transmission of SARS-CoV-2 to neonates is rare, but it still occurs, and there are concerns for infants with immature immune systems. Due to COVID-19 in neonates being so rare, there is a lack of studies with appropriate comparison groups. A team of researchers from the Centers for Disease Control and Prevention (CDC) in this study used a large US electronic healthcare dataset to compare indicators of severe illness in newborns with and without COVID-19 diagnosis during birth.

This study is published in the Journal of Perinatology.  

The study

Between March and December 2020, 701,777 recorded births were occurring in 609 US hospitals, of which 49% were non-Hispanic white, 46.5% used Medicaid, and 9.2% were premature. There was a total of 209 recorded COVID-19 cases during the birth hospitalizations. The majority of newborns with COVID-19 were born early preterm when compared to infants without the disease. Of the newborns with COVID-19, 69.9% displayed no signs of severe disease.

The risk of developing sepsis or requiring ICU admission was elevated in term/preterm newborns with COVID-19 when compared to those without COVID-19. However, of the newborns with COVID-19, 77.4% displayed no indicators of severe illness. Early preterm newborns who were positive for COVID-19 were at an elevated risk of needing invasive ventilation compared to those without the disease.

With Hispanic newborns, the SARS-CoV-2 positive infants displayed a greater risk of respiratory complications when compared to Hispanic newborns without the disease. There was an elevated risk observed for ICU admissions in non-Hispanic “other/unknown” race newborns and an increased risk of sepsis in non-Hispanic white term/preterm newborns with COVID-19 compared to those without COVID-19.

There was an increased risk observed for mechanical ventilation and respiratory complications in non-Hispanic Black newborns who were SARS-CoV-2 positive. Early preterm Hispanic infants with COVID-19 were at an elevated risk of respiratory complications, and the same was observed for non-Hispanic “other/unknown” race newborns, as well as increased risk of sepsis and the need for invasive ventilation. Out of all the newborns requiring admissions to ICU, those with COVID-19 had to remain there for a significantly more extended period when compared to those without COVID-19.  

Implications

From the data collected for this study, it appeared that the incidence of COVID-19 in newborns between March and December 2020 was rare. Therefore, the results from the study suggest that term/preterm newborns who were COVID-19 positive may not be at an elevated risk of respiratory complications or require mechanical ventilation but might be at an increased risk of sepsis and ICU admission.

Also, early preterm newborns that have COVID-19 may not be at an elevated risk of ICU admission and respiratory complications but they might be at an increased risk of requiring invasive ventilation. Future studies may explore changes in the risk profile of newborns with COVID-19.