Association between co-sleeping in the first year of life and preschoolers´ sleep patterns.

This study aimed to investigate the association between co-sleeping practiced during the first year of life and preschoolers' sleep patterns. A cross-sectional study including toddlers was designed to analyze their sleep patterns. The Brief Infant Sleep Questionnaire, validated in Spanish, was used to measure sleep quality. A latent class analysis was performed to identify qualitative subgroups in the sample and explore the effects of co-sleeping. The sleep patterns of 276 children were analyzed. A total of 181 (65%) parents reported having practiced co-sleeping with their children. The latent class analysis identified a two-class solution with two different sleep patterns. One of them showed a worse quality sleep pattern, which had a significant association with having practiced co-sleeping during the first year of life, and with the fact that they were still sleeping in the parents' room, among other characteristics related to co-sleeping and parental concerns. Breastfeeding also showed association with a worse quality sleep pattern.  Conclusion: Based on the present findings, co-sleeping during the first year of life appears to be associated with poor sleep patterns in young preschoolers. What is Known: • Co-sleeping shows benefits for infants and parents, mainly facilitating successful breastfeeding. • Literature on the effect of co-sleeping in lately sleep quality in children and their parents is very limited. What is New: • Co-sleeping practiced during the first year of life could be associated with a worse sleep pattern measured with BISQ-E tool. • A balance between the correct practice of co-sleeping and the achievement of a healthy sleep routine in preschool should probably be part of parents' health education.