Sir.—In their article in the May 1989 issue of AJDC, Chasnoff et al1 are misled in their belief that an autopsy can rule out lethal trauma in an infant who is presumptively diagnosed to have died of sudden infant death syndrome (SIDS). It is recognized in forensic pathology that young infants who die of external airway obstruction, accidental or otherwise, may have no pathologic changes on autopsy that indicate lethal injury by suffocation or smothering. In many cases of sudden infant death, death-scene investigation may be the only way to determine why a healthy infant died suddenly and unexpectedly at home.2,3
The data described by Chasnoff and coworkers are based on live infants. However, these infants are unsuitable controls for a study of infants who die of SIDS. The selection of controls in any prospective study of infants who died of SIDS should be restricted to healthy