How Old Can a Man Be and Still Father a Child? Age, Sperm Quality and Child Health

A man approaching fifty, or one entering a new marriage, may at some point ask: “Can I still become a father at this age, and will my child's health be affected?” According to news reports based on TÜİK data, Turkey's total fertility rate fell to 1.42 in 2025 and the average age of men at first marriage was 28.5; postponing children has become common.

Unlike the menopause in women, there is no clear “deadline” in men; sperm production continues throughout life. However, sperm characteristics change on average with age, time to pregnancy may lengthen and some rare conditions in the child may become slightly more likely. This article explains what changes and what does not with advanced paternal age, the limits of the evidence and when to be assessed.

Is there a “deadline” for men, like the menopause in women?

No. In men, sperm production continues throughout life in cycles of about three months in the testicles, so there is no defined upper age limit for fatherhood. But “continues” does not mean “is unaffected by age”: studies report that with age, semen volume, sperm motility and DNA integrity decrease on average, and time to pregnancy may lengthen. These are average trends; individual variation is large, and the definition of “advanced paternal age” varies between studies (usually over 40 or 45).

What changes with age in sperm quality, and what does not?

Reviews report these average trends as age advances:

• Semen volume and motility: Volume may decrease; the proportion of sperm moving forward tends to fall.
• Shape: The proportion of normally shaped sperm may fall slightly.
• DNA integrity: The proportion of sperm with DNA damage has been reported to rise (explained in our article on sperm DNA fragmentation).
• Sperm count: No consistent change with age has been shown.

What does not change matters too: sperm production continues, the semen analysis of many older men is compatible with conceiving, and the changes are usually small. The pure effect of age is hard to isolate, because weight, smoking, chronic illness and medication also increase with age. An individual's own situation is seen only on a semen analysis (see the related article on our site).

Does falling testosterone affect fatherhood?

Testosterone tends to decline gradually with age; however, there is no sudden drop resembling the menopause and no defined threshold for “andropause”, and in many men the level stays normal (symptoms are covered in our article on testosterone deficiency).

There is an important trap: when a child is planned, testosterone given from outside can suppress sperm production, sometimes to the point of no sperm at all in the semen; the same logic applies to anabolic steroids. A man who wants a child should discuss this with his doctor before starting hormone treatment. Erection and ejaculation problems also become more common with age and can make conception harder; these are often manageable problems.

How long does pregnancy take, and why does the partner's age matter?

In observational studies, advanced paternal age has been linked to pregnancy happening later; it is hard, however, to separate this from the woman's age. The factor that most often determines fertility is the woman's age: the number and quality of eggs fall markedly after 35, and especially after 40.

Assessment is therefore always made as a couple: finding a problem in the man does not mean there is none in the woman, and the reverse is also true. Looking at both together saves time and replaces blame with a shared plan.

What is known about child health with advanced paternal age?

The great majority of children of older fathers are born healthy. Even so, observational studies report small but recurring associations:

• Rare single-gene conditions: The likelihood of some conditions, such as achondroplasia, rises with paternal age; their absolute frequency is low.
• Neurodevelopmental conditions: Some studies report an association with autism spectrum conditions and schizophrenia; the effect is small, cannot be fully separated from maternal age and family history; causation is not considered proven.
• Pregnancy outcomes: An association with miscarriage and preterm birth has been reported; results are inconsistent and the evidence is limited.

These associations are not a prediction for any single child; the risk rises, but the absolute value remains small.

What does the sperm mutation study say, and what does it not say?

In a basic-science study published in Nature (81 sperm samples), the proportion of sperm carrying mutations capable of causing disease was about 2% in the early 30s and about 3–5% between the ages of 43 and 74; the researchers explain this by some mutated sperm stem cells gaining a growth advantage over time (selection). The data should be read as follows:

• Disease frequency in children was not measured: The study examined sperm samples, not children who were born.
• Not every mutated sperm reaches a child: Only one of millions of sperm starts a pregnancy.
• The risk does not start from zero: Young men also have a proportion; the rise is gradual and the absolute value remains small.

This finding is for information, not for panic. Extra genetic testing is generally not recommended routinely for every older prospective father; with a family history of an inherited condition, genetic counselling makes sense.

What can a prospective father change through health and lifestyle?

Age cannot be changed, but some other factors that affect sperm can:

• Weight: Excess weight can adversely affect hormone balance and sperm characteristics; gradual weight loss is beneficial.
• Smoking, alcohol and heat: Smoking is adversely associated with sperm characteristics; heavy alcohol use can suppress testosterone and sperm production; frequent saunas and very hot baths can raise testicular temperature.
• Chronic illness and medication: Diabetes, high blood pressure, antidepressant-group medicines, some prostate medicines and hormone treatment can affect erection, ejaculation or sperm characteristics; medicines should not be stopped without consulting a doctor.

Because the sperm production cycle lasts about three months, changes take about that long to show on a semen analysis. No lifestyle change removes the effect of age; evidence that supplements reverse age-related change is limited (explained in our article on sperm quality). The aim is not to create guilt, but to do what can be done.

After how many months should assessment be made, and what is the first step?

Generally, if pregnancy has not occurred within 12 months of regular unprotected intercourse, assessment of the couple is advised; if the woman is 35 or older, this period generally drops to 6 months. If the woman is over 40, or there is a risk such as irregular periods, varicocele, testicular surgery or a history of cancer treatment, it is reasonable to seek advice without waiting.

On the male side the first step is simple and painless: a detailed history, a genital examination and a semen analysis; depending on the result, hormone tests and, where needed, sperm DNA fragmentation or genetic assessment may be added. A gynaecological assessment of the female partner at the same time matters, as time is usually shorter on her side.

Sperm freezing can be discussed before cancer treatment, surgery or testosterone treatment, or when a child is planned for later and sperm characteristics are borderline. A frozen sample keeps the characteristics of the day it was frozen; however, it does not determine the pregnancy outcome in advance. For a healthy man, age alone is not a reason for routine freezing (explained in our article on sperm freezing).

When should a doctor be consulted?

A urology and andrology assessment is advised in the following situations:

• No pregnancy within 12 months of regular unprotected intercourse (generally 6 months if the woman is 35 or older); earlier in situations such as a partner over 40
• Changes in erection, ejaculation or sexual desire that make conception harder
• Varicocele, an undescended testicle, testicular surgery or injury, a history of cancer treatment, or a previous semen analysis that was borderline
• Use, or a suggestion, of testosterone treatment or anabolic steroids while a child is planned
• A family history of an inherited condition, recurrent miscarriage or a child born with a congenital problem; for genetic counselling
• A testicular lump, swelling, ongoing pain or blood in the semen; sudden, severe testicular pain needs emergency care without delay (112 in Turkey)

Men have no deadline like the menopause; yet with age sperm characteristics change on average, time to pregnancy may lengthen and the likelihood of some rare conditions in the child may rise slightly. The factor that most often determines fertility is the female partner's age; assessing as a couple, in good time and with information rather than panic, is the sensible course. Assoc. Prof. Zülfü Sertkaya practises in urology and andrology in Istanbul; male fertility assessment and counselling for prospective fathers are carried out with individual assessment and confidentiality.

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