Infant gender, shared sleeping and sudden death

Aim: To determine whether there is a gender imbalance in infant deaths in shared sleeping compared to solitary sleeping situations. Methods: Examination of autopsy reports of 133 infants aged between 7 and 364 days autopsied over a 19-year period from January 1991 to December 2009 was undertaken where death had either been attributed to SIDS, or had been classified as undetermined or unascertained. Cases were divided into two groups of solitary sleepers and shared sleepers, and the ratio of male to female cases was compared. Results: Ninety-five solitary sleepers were aged from 1 to 11 months (average 4.1 months) and consisted of 63 males (age range 1 to 11 months) and 32 females (age range 1 to 10 months). The 38 shared sleepers were aged from 1 week to 12 months (average 2.6 months) and consisted of 17 males (age range 2 weeks to 5 months) and 21 females (age range 1 week to 10 months). The male to female ratio in the solitary sleepers was approximately 2:1 and in the shared sleepers was 0.8:1, a statistically significant difference (p = 0.02). Conclusion: The lack of a male predominance typical of SIDS cases in infants who were sleeping with others, compared to those who were sleeping alone, suggests that these situations may be different. It is possible, therefore, that different lethal mechanisms may be involved in some shared sleeping situations.