When it comes to our ears that a famous man has been a father at an advanced age, we take it with a certain skepticism. Men age 70 or older get to be parents. The key question, gossip aside is: How old is a man fertile?
Statistics show that there are a large number of children born to parents over the age of 50, while this is very rare for women. It is known that in women over 35 years of age there is an increase in the reproductive risks associated with motherhood. Is it the same with parents?
Testicular volume is directly related to the amount of sperm produced. Age alone does not reduce testicular size until the eighty years of age.
In addition to the reduction in volume, aging produces a decrease in the efficiency of the sperm forming process in the testis. There are fewer precursor cells, spermatogonia, and many are abnormal, giant and with multiple cell nuclei. In addition, the morphological features of the aging testicles include a reduced number of type A spermatogonia as well as giant spermatids and the seminiferous tubes begin to present diverticula, and then suffer sclerosis. The number of testosterone-producing cells, Leydig cells, which may also be multinucleated, are also reduced.
Testicular sclerosis goes hand in hand with atherosclerosis, since vascularity defects produce sclerosis of the testicular parenchyma. The prostate can also hypertrophy with age in 50% of men aged 50 years and in 90% of men over 90 years.
Seminal quality in elderly men
With all these changes, it is normal that the seminal quality suffers. All changes are developed gradually, there is no sudden presentation. There is no age at which man ceases to be fertile. There is a decrease in the volume of semen and motile spermatozoa with age, at a rate of 0.5% per year and 0.7% per year respectively. Most of the sperm volume is derived from the seminal vesicles, and one of its secretions, fructose, also decreases with age,
As for the concentration of spermatozoa per milliliter there is no consensus: some say that it remains unchanged, while others say it decreases.
As for the morphology of spermatozoa, the annual decrease in the percentage of normal spermatozoa oscillates between 0.2% and 0.9%.
In addition, fertility may be diminished by other disorders such as erectile dysfunction. The frequency of erectile dysfunction increases to almost 40% of men over the age of 74 years. The situation is aggravated in smokers. Smoking not only produces direct effects on motility and sperm concentration but is also strongly related to erectile dysfunction. Smoking doubles the risk of erectile dysfunction at 10 years seen. Concurrently, the probability of conception decreases by 3% for every year of man's age.
With assisted reproduction methods, seminal quality requirements are greatly reduced, especially in intracytoplasmic sperm injection in the oocyte (ICSI). However, in the case of in vitro fertilization (IVF) and intrauterine insemination, problems may occur in males over 50 years of age. Overall, studies indicate that men begin to contribute to the reduction of the fertility of a couple in their thirties.
Risk of genetic alterations in spermatozoa of elderly men
The association between elevated paternal age and severe birth defects is the reason why the age of sperm donors is limited to 40 years in some countries.
Aneuploidy, the presence of a chromosome of more or less, is the main genetic cause of pregnancy loss. The incidence of aneuploidies is 2% and sperm appears to increase with age.
Paternal advanced age is associated with diseases of complex etiology such as schizophrenia and inherited autosomal dominant diseases such as achondroplasia and Apert syndrome.
The literature also indicates an increased risk of trisomy 21. Couples should be aware of these age-dependent changes in fertility and predisposition to genetic risks. They should be informed, however, that the contribution to the reduction of male fertility is less pronounced than that of the female and that the absolute risk for alterations is low.
Infertility in elderly men due to infections
In man, as in women, there are alterations in the parameters of seminal quality that can have several causes. In addition to age per se, factors such as urogenital infections, vascular diseases or an accumulation of toxic substances may be responsible for a deterioration in seminal parameters. Men older than 40 usually have accessory gland infections, which is associated with the death of spermatozoa produced by contact with infected seminal plasma. What is that proportion? 10% of infected men infertile over 40.
Infertility in older men due to environmental pollution
There is also an effect of environmental pollutants, which accumulate with age. The concentration of polychlorinated biphenyls is directly related to lower production and motility of spermatozoa. The concentration of cadmium also increases with age in the testes, epididymides and prostate.