Objective: To evaluate mortality on the first day of life by minute and hour, and examine changes in major causes of death in the past three decades.
Study design: We evaluated mortality on the first day of life by the hour (0, 1, …, 23 h), and in the first hour by 5-min block (0-4, 5-9, …, 55-59 min) using data on cause of death for 15,690 infants in Canada from 1981 to 2012.
Results: Infant mortality on the first day declined from 2.60 per 1000 in the 1980s to 1.26 in the 2000s. The decline was greater at 6-23 h than at 0-5 h of life, and among infants with congenital anomalies compared with prematurity and birth asphyxia.
Conclusion: Infant mortality is highest on the first day of life. More focus on prematurity and birth asphyxia in the first 5 h of life is needed to improve infant mortality.