Koehler et al described criteria for the Simultaneous Sudden Infant Death Syndrome (SSIDS). This unfortunate but rare condition occurs when twins die within a brief period of each other, with each infant meeting the criteria for the Sudden Infant Death Syndrome (SIDS).


Definition of SIDS (National Institute of Child Health and Human Development, NICHD, 1991 Expert Panel):

(1) infant age from 7 to 365 days old

(2) no cause of death identified at autopsy

(3) toxicology and metabolic screening tests negative

(4) medical history of the infant and mother negative

(5) no cause of death found at the death scene


Additional criteria for SSIDS:

(6) infants either monozygotic or dizygotic to each other. Usually this implies twins, but triplets, etc. could be involved.

(7) death occurs within 24 hours of each other ("simultaneous")



• Willinger et al in the 1991 NICHD included all infants < 1 year of age. Some investigators do not include neonates < 7 days of age.



• V. Leavitt ( states that some of the anectodal cases of multiple SIDS cases in the same family later turned out to involve maternal infanticide. This needs to be carefully excluded before accepting the diagnosis of SSIDS.


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