A new study led by researchers at Penn State College of Medicine has revealed that the risk of sudden unexpected infant death (SUID) and sudden infant death syndrome (SIDS) increased during the COVID-19 pandemic, particularly in 2021.

The findings, published on September 26 in JAMA Network Open, suggest a possible link between the resurgence of seasonal respiratory viruses and the rise in SUID rates. Lead researcher Emma Guare, a fourth-year medical student at Penn State, noted, “The cause of SUID is believed to be multi-factorial. We wanted to better understand the connection between infection and SUID, especially as endemic infection rates shifted during the pandemic.

The research team analyzed mortality data from the CDC between March 2018 and December 2021, identifying 14,308 cases of SUID. When comparing monthly cases to pre-pandemic levels, the team observed an increase in both SUID and SIDS risk during the pandemic, with the highest increase occurring in 2021. SUID and SIDS rates rose by 9% and 10%, respectively.

Between June and December 2021, monthly SUID rates ranged from 10% to 14% higher compared to pre-pandemic levels. This period coincided with an unexpected off-season surge of respiratory syncytial virus (RSV) cases, which usually peak between October and April.

Co-author Dr. Erich Batra, associate professor at Penn State, commented, “It could be that infections increase the underlying vulnerability factors in infants, potentially contributing to SUID or SIDS.

The researchers emphasized the need for further investigation into the role of infections in SUID and SIDS, as well as the continued importance of safe sleep practices for infants.

While the study provides valuable insights into the potential relationship between respiratory infections and infant deaths, it highlights the complexity of SUID and SIDS.