those between 45 and 49 years old were 64% more likely to have an infant with a 1-minute total Apgar score of between 1 and 3

Older Paternal Age Could Mean Sicker Babies

A recent study shows that new fathers in their 40s and 50s tend to have newborns with lower Apgar scores than fathers in their 20s. The Apgar score rates the infant on 5 aspects: respiratory effort, heart rate, reflex irritability, muscle tone, and skin color, with a value of 0 to 2 (worst to best) for each one. The score is calculated at 1 and 5 minutes after birth.

Researchers at the University of Aarhus in Denmark analyzed data from >70,000 couples who had their firstborn between 1980 and 1996. Compared with new fathers in their 20s, those between 45 and 49 years old were 64% more likely to have an infant with a 1-minute total Apgar score of between 1 and 3. Newborns with fathers over age 50 were 49% more likely to score in this range as well (a score of 10 is optimal). All fathers over age 45 were at an increased risk of having an infant with a 5-minute Apgar score of <7.

The researchers stated, "The biologic link between advanced paternal age and low Apgar scores is unknown." Some studies have shown, however, that "expression of specific paternal genes is crucial for the placental development, and that chromosomal aberrations tend to increase with paternal age." The findings were published in the July 2006 issue of Epidemiology.