Age matters, but prevention can protect reproductive health.
BUENOS AIRES, Argentina | June 2026
Fatherhood after the age of 40 is increasingly common, but specialists warn that male fertility is not unaffected by time. For decades, reproductive difficulties were treated mainly as a women’s health issue, even though the male factor is involved in approximately half of infertility cases among couples. Men do not experience a reproductive menopause comparable to women, yet sperm quality can decline progressively with age. Preventive evaluation and healthier habits can therefore become important long before a couple begins trying to conceive.
One of the most persistent myths is that men remain fully fertile throughout life. Specialists say this belief often delays medical consultation and places an unfair burden on women when pregnancy does not occur. Sexual performance and fertility are also frequently confused, although normal sexual function does not guarantee normal sperm production. A semen analysis may reveal abnormalities even in men who have no visible symptoms.
Changes in sperm quality usually become more noticeable after 40. Medical evaluations may detect lower concentration, reduced motility and alterations in morphology, all of which can make fertilization less efficient. Specialists also emphasize a rise in sperm DNA fragmentation and the gradual accumulation of spontaneous genetic mutations. These changes can lengthen the time required to achieve pregnancy and may increase certain reproductive risks.
The decline is usually slower than the reduction in female fertility after the mid-30s, but it is still relevant. One expert estimates that semen quality may worsen by approximately one percent each year after 40. By age 50, the difference may be significant compared with a decade earlier. The effect varies considerably between individuals because age interacts with health, genetics, environmental exposure and lifestyle.
Men over 40 may also have a lower probability of fathering a child than younger men. Specialists cited in the report estimate a reduction of around 30 percent in reproductive probability compared with men under 40. DNA fragmentation may also increase progressively with age. These figures do not mean that natural conception is impossible, but they challenge the idea that male reproductive capacity remains unchanged indefinitely.
Lifestyle is one of the most important modifiable factors. Smoking, obesity, physical inactivity, poor nutrition and inadequate sleep can all affect hormonal balance and sperm production. Excessive alcohol consumption and exposure to environmental or occupational toxins may add further damage. Improving general health is therefore one of the most effective ways to support male fertility.
Sleep deserves particular attention because testosterone production and metabolic regulation depend partly on adequate rest. Chronic sleep deprivation can disrupt hormonal patterns and contribute to weight gain, stress and reduced physical recovery. Regular exercise can help, provided it is balanced and does not involve harmful substances. Specialists caution that externally administered testosterone and anabolic steroids may severely suppress sperm production.
This warning is especially important because some men use testosterone to increase muscle mass, energy or sexual performance without understanding its reproductive consequences. External testosterone can signal the body to reduce or stop its own sperm production. A man may feel physically stronger while becoming temporarily or, in some cases, seriously infertile. Anyone planning future fatherhood should discuss hormone use with a qualified physician.
Varicocele is another preventable or treatable condition requiring attention. It involves enlargement of veins in the scrotum and can raise local temperature or impair testicular function. Specialists report that it is present in a substantial proportion of men evaluated for infertility. Early detection can help prevent progressive damage, particularly in adolescents and young adults.
Past illnesses and injuries can also influence fertility years later. Mumps, prolonged fever, testicular trauma, infections and some sexually transmitted diseases may affect sperm production. Many men do not connect childhood or adolescent health events with later reproductive problems. A complete medical history can therefore provide important clues during evaluation.
There is no universal recommendation that healthy men routinely freeze sperm for social reasons. Male fertility generally declines more gradually than female fertility, making preventive cryopreservation less necessary for most young men. Specialists usually recommend it before chemotherapy, radiotherapy, immunosuppressive treatment or vasectomy. It may also be considered when semen results are borderline, sperm concentration is severely reduced or fatherhood will be postponed for many years.
Men with a family history of infertility or known reproductive abnormalities may also benefit from discussing sperm freezing. Cryopreservation is technically feasible and can preserve reproductive options before expected medical risk. However, it should not replace preventive care or medical evaluation. For most men, maintaining health and identifying problems early remain more useful than freezing sperm without a specific indication.
A semen analysis is usually the first basic test when fertility concerns arise. It evaluates concentration, movement and morphology, and may be supplemented by tests for DNA fragmentation or hormonal function. The examination is relatively simple and accessible, but many men postpone it because of embarrassment or fear. Specialists stress that an abnormal result is a medical condition, not a judgment about masculinity.
Couples are generally advised to seek evaluation after 12 months of regular unprotected intercourse without pregnancy. Consultation should occur after six months when the female partner is older than 35 or when either partner has a known risk factor. Both members of the couple should be assessed at the same time. Evaluating only the woman can delay diagnosis and treatment.
Fertility difficulties also carry an emotional burden. Stress, guilt and anxiety may intensify when conception does not happen as expected. Psychological support can be valuable alongside medical treatment, particularly when couples face repeated testing or assisted reproduction. Open communication helps prevent one partner from being treated as solely responsible.
Fatherhood after 40 remains possible and increasingly frequent. Age does not determine the outcome by itself, but it should be included in reproductive planning rather than ignored. Weight management, exercise, better sleep, avoidance of tobacco and excessive alcohol, and careful use of medications can improve reproductive health within several months. Early consultation gives men and couples more options and more accurate information.
Fertility improves when prevention begins before urgency. / La fertilidad mejora cuando la prevención comienza antes de la urgencia.