IntroductionRecent literature has shown that sleep patterns are shaped during the first years of life, playing a relevant role in children’s functioning. We focused on comparing sleep patterns in infants and toddlers in Spain before and during COVID-19 home confinement to assess the immediate impact on sleep patterns. Methodse compared data from two cross-sectional surveys from parents of 1,658 children three to 36 months of age from Spain. One conducted before COVID-19 (2017-2018, n=1,380) and another during COVID-19 pandemic (March-May of 2020, n=254). We used an internet self-administrated questionnaire using the Brief Infant Sleep Questionnaire (BISQ) criteria in both surveys.ResultsDuring confinement infants and toddlers went to sleep later (median bedtime 21.5 before confinement vs. 21.6 during confinement p=0.004). We found a statistically significant increase in infants’ and toddlers’ sleep latency by >30 minutes during confinement (p<0.001). Based on the recommended BISQ criteria for classifying inadequate sleep patterns, we observed a statistically significant increase in poor sleepers meeting at least one criterion during confinement (p<0.001). ConclusionsParents during COVID-19 home confinement reported several factors affecting the quality of their children’s sleep. Follow-up studies can help understand the potential long-term effects of the COVID-19 pandemic on sleep patterns.