It is well known that a woman’s age has a large impact on her fertility. However, what impact does a man’s age have on his partner’s fertility and pregnancy? Recent research tells us that the father’s age impacts these issues, though the overall effect is quite modest compared to the effect to that of the mother.
In contrast to women (who are born with all the eggs they will ever have), men continue to make sperm throughout their life. As men age, the volume of their ejaculate goes down, as does the percentage of normal-appearing sperm in their ejaculate. However, this does not necessarily correlate with a decrease in ability to father a child.
Interestingly enough, advanced paternal age (> 40 years) may be linked to a slightly increased risk of miscarriage. Also, there appears to be a slightly higher birth defect rate in couples with older fathers. In addition, there may be slight increases in the risk of schizophrenia and autism in offspring of older fathers.
To avoid even slight risks, it would reasonable for men to consider the completion of childbearing with their partner by the age of 40. However, keep in mind that the risks associated with fathering a child at a later age indeed appear to be minimal