Paternal age & fertility
The discussion about age and fertility focuses almost always on the woman — and rightly so, since the effect of her age is strong and clear. Increasingly, however, the question of the man’s age is also raised.
Men do not have an abrupt “biological deadline” like the menopause. They produce sperm throughout life. But this does not mean age plays no role — its effect is simply milder and more gradual.
Does a man’s fertility decline with age?
Yes, but mildly and gradually. Over the years, small changes are seen in some semen parameters — mainly volume and motility — and a gradual rise in DNA fragmentation. Sperm concentration is affected less.
In practice, the time a couple needs to conceive tends to increase when the man is older, even after taking the partner’s age into account. The effect, however, remains clearly smaller than that of the woman’s age.
What does “advanced age” mean for a man?
There is no universally accepted cut-off. Many studies use 40 to 45 years as a reference point, beyond which some changes begin to become more apparent. This is a gradual trend, not an abrupt “threshold”.
It is important not to create excessive fear: the vast majority of older men father healthy children. We are talking about small changes in the average of a population, not certainties at the individual level.
Does the father’s age increase risks for the child?
Advanced paternal age is linked to a small increase in certain risks. Because the cells that produce sperm divide continuously, more new (de novo) mutations accumulate over the years.
This is associated with a slightly higher chance of certain rare genetic conditions (such as achondroplasia) and with a small relative increase in the risk of some neurodevelopmental disorders, such as autism and schizophrenia. It must be stressed that the absolute risk for any individual child remains small.
Does the man’s age affect IVF outcomes?
In IVF, the dominant factor for success remains the woman’s age and egg quality. The independent effect of the man’s age on success rates, when young eggs are used, appears small.
When both partners are older, however, the effects may add up. Interpreting the data is difficult precisely because the ages of the two partners usually go together.
What can an older man do?
The same measures that apply to every man: a healthy lifestyle, avoiding smoking, maintaining a normal weight and addressing any medical problems. There is no specific “anti-ageing” therapy for sperm with proven benefit.
For couples planning to delay parenthood, sperm cryopreservation at a younger age is an option that can be discussed, though it is less often necessary than the corresponding option for the woman.
What is the balanced conclusion?
A man’s age matters, but its effect is mild and clearly smaller than that of the woman’s age. The associated risks for the child exist but are small in absolute terms.
The practical message for a couple is simple: if you are planning children, time counts for both — with the woman’s age remaining the most decisive factor. An honest discussion with the doctor helps put things in their proper perspective.
Summary
A man’s fertility declines with age, but mildly and gradually, without the abrupt “deadline” of the female menopause. Small changes are seen in the semen and a gradual rise in DNA fragmentation. Advanced paternal age is linked to a small increase in certain rare genetic conditions and neurodevelopmental disorders, but the absolute risk for any child remains small. Overall, the effect of the man’s age is clearly smaller than that of the woman’s age.
Sources: ASRM, “Guidance regarding gamete and embryo donation” / recommendations on advanced paternal age; European Association of Urology (EAU), Guidelines on Sexual and Reproductive Health (Male Infertility); Kühnert & Nieschlag, “Reproductive functions of the ageing male”, Human Reproduction Update.
⚕ Medically reviewed by Prof. Stratis Kolibianakis · Thessaloniki Medical Association Reg. No. 16340
ARTICLE 14 · INFERTILITY & DIAGNOSIS
