Rates of sudden infant deaths increased during the COVID-19 pandemic, a new analysis suggests – and altered transmission of illnesses such as respiratory syncytial virus (RSV) might be linked to the rise.

Writing in JAMA Network Open, researchers analyzed U.S. mortality data from 2018 through 2021. In that period, there were 14,308 cases of sudden unexpected infant death (SUID) — an umbrella term that describes the unexpected death of a child under age 1. Infants who died of sudden infant death syndrome (SIDS), which occurs during sleep, were included in the count.