Some SBS/head trauma cases recently in the news involve twins, reminders that raising multiples brings extra stress...
Elmont NY mother of twins (2008)
North Bay ON trial of father for inflicting injuries on twin boys (2004)
Rapid City IA boyfriend inflicting head injury on a 21 month twin
Raising Twins has a very good blog post about SBS for the parents of twins (indeed, for all parents and caregivers: she emphasizes the importance of educating to all caregivers and being alert for symptoms of PPD)..