Sudden Unexpected Postnatal Collapse: A Retrospective Cohort Study Describing Incidence, Risk Factors and Role of Perinatal Transition

Aim This study aimed to investigate the incidence, risk factors and possible aetiology of sudden unexpected postnatal collapse (SUPC), a potentially fatal yet poorly understood event. Methods In a retrospective cohort, patient records from 483 284 infants born in Stockholm, Sweden, between 2002 and 2022 were screened for SUPC‐related diagnoses. SUPC was defined as a collapse within the first 7 days of life in near‐term infants with good postnatal adaptation. Maternal, infant and event characteristics were collected. Urine was analysed for prostaglandin E 2 (PGE 2 ) metabolites in a subgroup of cases. Results We identified 149 cases of SUPC, corresponding to an incidence of 31 per 100 000 live births, exceeding that of early onset sepsis caused by Group B Streptococcus. Half the SUPC cases occurred during the first four postnatal hours. The mortality was 7% and 26% suffered from neurological sequelae. The highest risk of SUPC coincided with the postnatal peak in PGE 2 levels. Conclusion All newborn infants were at risk of SUPC, especially within 24 h of birth. SUPC was associated with early unsupervised skin‐to‐skin care and bed sharing. Guidelines promoting safe sleep and skin‐to‐skin care should be implemented to prevent SUPC and save the lives of newborn babies.