Background: New evidence suggests that advanced paternal age is a reproductive hazard, but we do not know whether paternal age affects the physical conditions of newborn infants as measured by the Apgar score.
Methods: We conducted a register-based cohort study of 70,347 couples and their first singleton infants by using data from the Danish Fertility Database (1980-1996). Information on Apgar score was obtained by linking the children to the National Birth Register.
Results: The odds ratio for having a baby with a 1-minute Apgar score of 1-3 was 1.64 (95% confidence interval = 1.08-2.48) for fathers 45 to 49 years of age and 1.49 (0.76-2.94) for fathers 50+ years compared with fathers 20 to 29 years (P for trend = 0.011). The risk of having a 5-minute Apgar score less than 7 increased among fathers 45+ years old (P for trend = 0.178).
Conclusions: Our data suggest a modest effect of advanced paternal age on the Apgar score.