Paternal age: are the risks of infecundity and miscarriage higher when the man is aged 40 years or over?

BACKGROUND

Maternal age of 35 years or over is a well-known risk factor for human reproduction that has been extensively investigated by demographers and epidemiologists. However, the possibility of a paternal age effect has rarely been considered. We carried out review of the literature to investigate the effect of paternal age on the risks of infecundity and miscarriage.

METHODS

We carried out a MEDLINE search and checked the exhaustiveness of our reference list.

RESULTS

We identified 19 articles analysing the effect of paternal age. Epidemiological studies provided evidence that paternal age older than 35-40 years affects infecundity. However, the few studies based on data from assisted reproductive techniques (especially IVF with ovum donation) do not confirm this finding. All studies analysing the effect of paternal age on the risk of miscarriage showed an increased risk in men aged 35-40 years or over. Other studies have shown some evidence for a paternal age effect on late foetal deaths.

CONCLUSION

The risks of infecundity and miscarriage increase with paternal age. Two main hypotheses can be considered. First, these risks increase after the age of 35-40 years. However, a later paternal age effect (after 45-50 years) cannot be excluded. Second, due to the interaction of the ages of the two partners, the risks of infecundity and miscarriage may be higher when both partners are older (woman aged 35 years or over and man aged 40 years or over).