A study from Sweden reviewed all cases from five delivery units of late preterm and term infants who appeared to be healthy but collapsed within 24 hours of birth. Data from two and a half years were analyzed. The incidence of sudden unexpected postnatal collapse was 38 per 100,000 live births. The following variables were associated with these events: unsupervised breastfeeding, prone position, primiparity and use of a smartphone by the mother. Some of these infants underwent hypothermia treatment for hypoxic ischemic encephalopathy.