Bed-sharing in the first four months of life: a risk factor for sudden infant death.

Aim: To investigate the risk of sudden infant death in the Netherlands during bed-sharing in the first half year of life and the protective effect of breastfeeding on it.
Methods: During a 10-year period between September 1996 and September 2006 nationwide, 213 cot deaths were investigated.
Results and Discussion: Of 138 cot deaths of less than 6 months of age, 36 (26%) bed-shared. In a reference group of 1628 babies from infant welfare centres only 9.4% were bed-sharing in the night prior to the interview. After correction for smoking of one or both parents the odds ratio for cot death during bed-sharing with parents decreased with age from 9.1 (CI 4.2-19.4) at 1 month, to 4.0 (CI 2.3-6.7) at 2 months, to 1.7 (CI 0.9-3.4) at 3 months and to 1.3 (CI 1.0-1.6) at 4 through 5 months of age. The excess risk (OR > 1) associated with bed-sharing is itself not significantly influenced by the presence or absence of breastfeeding.
Conclusion: Bed-sharing is a serious risk factor for sudden infant death for all babies of less than 4 months of age. From 4 months onwards bed-sharing did not contribute significantly to the risk of cot death anymore in our study.