Babies with older fathers are more likely to be born early, a study from Italy confirms. The risk is particularly high for very preterm infants, meaning those born before 32 weeks' gestation, and for younger mothers, researchers found.
Some studies have suggested that infants born to older fathers face a greater risk of certain birth defects and diseases, while pregnancy complications such as miscarriage and preterm delivery have also been linked to paternal age, Dr. Paola Astolfi of the University of Pavia and colleagues note in a report in the journal Epidemiology.
To investigate the association between a father's age and preterm birth risk, the researchers looked at just over 1.5 million birth records, representing all Italian mothers aged 20 to 29 giving birth for the first time between 1990 and 1998. The researchers chose women in this age group because they face the lowest risk of pregnancy complications, including preterm birth.
Risks increase with father's age
The risk that a child would be born before 37 weeks gestation increased with a father's age, the researchers found, with the strongest effect of paternal age seen for very preterm births.
The effect of a father's age also was greater among the women aged 20 to 24 compared to those aged 25 to 29.
For example, men aged 45 to 49 were nearly twice as likely to father infants born before 32 weeks if the mother was between 20 and 24 years old, compared to fathers aged 25 to 29.
"A wide paternal-maternal age difference might represent a risk factor for several different types of adverse conditions," Astolfi and colleagues write.
They also note that older men may have accumulated more potentially harmful genetic mutations due to environmental pollution and other causes, compared to younger men.