Five-Minute Apgar Score and the Risk of Mental Disorders During the First Four Decades of Life: A Nationwide Registry-Based Cohort Study in Denmark

Objectives:The associations of long-term risks of the full spectrum of mental disorders with clinically reassuring but suboptimal score range 7-9 remain unclear. This study investigated these associations during up to 38 years of follow-up. Methods:In a nationwide cohort study of 2,213,822 singletons born in Denmark during 1978-2015, we used cox regression to estimate the hazard ratio (HR) of mental disorders with a 95% CI. Results:A total of 3,00,679 (13.6%) individuals were diagnosed with mental disorders. The associations between suboptimal Apgar score 7-9 and mental disorders differed by attained age. In childhood (<= 18 years), declining Apgar scores were associated with increased risks of overall mental disorders with HRs (95% CI) of 1.13(1.11-1.15), 1.34 (1.27-1.41), and 1.48 (1.31-1.67) for Apgar scores of 7-9, 4-6, and 1-3, respectively, compared with a score of 10. A dose-response association was seen even within the score range from 9 to 7 (HR 1.11 [95% CI: 1.08-1.13], 1.14 [1.10-1.18], and 1.20 [1.14-1.27], respectively). Of note, individuals with scores of 7-9 had increased risks of organic disorders (HR: 1.27, 95% CI: 1.05-1.53), neurotic disorders (HR: 1.07, 95% CI: 1.03-1.11), and a wide range of neurodevelopmental disorders, such as intellectual disability (1.87, 1.76-1.98), childhood autism (1.13, 1.05-1.22) and attention deficit hyperactivity disorder (1.10, 1.06-1.15). In early adulthood (19-39 years), suboptimal Apgar scores 7-9 were not associated with the risks of overall and specific mental disorders. Conclusion:Infants born with clinically reassuring but suboptimal 5-min scores 7-9 are at increased risks of a wide spectrum of mental disorders in childhood.