Wennergren et al. (Acta Paediatrica, 2021): Swedish Infant Sleep Survey
In Sweden, 1 in 3 six-month-olds bed-share. Infant mortality is half the US rate.
Wennergren, Strömberg Celind, Goksör & Alm: Swedish national surveys of infant sleep practices. Bed-sharing among 6-month-olds rose from 20% in 2003-2004 to 33% in 2018. Strong positive correlation with breastfeeding. Sweden has one of the lowest infant mortality rates in the world (2.1 per 1,000, vs the US 5.1).
Wennergren and colleagues published a 2021 paper in Acta Paediatrica analysing Swedish national surveys of infant sleep practices over 15 years. Bed-sharing among 6-month-old infants nearly doubled, rising from 20 percent in the 2003-2004 survey to 33 percent in 2018.
The surveys also found a strong positive correlation between bed-sharing and breastfeeding rates. Sweden has one of the lowest infant mortality rates in the world (2.1 per 1,000 live births, compared with the US 5.1), and bed-sharing has been rising over the same period that infant mortality has been falling. The Swedish National Board of Health and Welfare (Socialstyrelsen) introduced a bed-sharing warning in 2013 aimed at preventing SIDS, but the gap between official guidance and family practice is wide and known to the agency, which has been reviewing its recommendations after criticism from parents and specialists.
33%
Swedish 6-month-olds bed-sharing (2018)
20%
Same metric, 2003-2004
2.1 / 1,000
Sweden infant mortality
5.1 / 1,000
US infant mortality
Why it matters
A country with one of the world's lowest infant mortality rates has seen bed-sharing rise from one in five to one in three of its 6-month-olds. The outcomes have improved over the same period, not worsened.
This is one finding from the research library behind How to Birth a Mother. Everything here traces back to a study, a dataset, or a systematic review.