Men don’t stop producing sperm throughout their lives, but the quality and motility of their semen decline with age. This can make it harder to get pregnant and increases the risk of chromosomal and genetic defects in children.
There are many reasons for low sperm count, including hormonal imbalances, dilated testicular veins (varicoceles), and genetic conditions such as Klinefelter syndrome or Y chromosome microdeletions.
Age at Menopause
Women often get a lot of attention when it comes to their biological clocks running out as they approach menopause, but men also experience a decline in fertility. A woman’s reproductive hormones decline gradually, starting around her late 30s, but men’s reproductive hormones start to drop earlier and are more steeply reduced than women’s.
Men’s sperm production may continue for life, but the quality of that sperm deteriorates with age. Studies have found that sperm motility, or how well sperm swims to the egg, is best before age 25, and lowest after age 55. This decrease in sperm quality, which happens despite frequent sex, is due to the natural aging process.
In addition, the sperm produced at a younger age tends to be healthier than sperm made at an older age. Because of this, men who have the option to freeze their sperm while they are still fertile in their 20s or early 30s should consider doing so. Although it is impossible to guarantee that freezing a man’s sperm will help him conceive, doing so can give his offspring the best chance of success. Sperm frozen at an earlier age can also give a man more options when he decides to start a family, as the sperm can be used later to fertilize eggs from his partner or other men.
Age at Fertility Decline
Many women are familiar with the fact that a woman’s fertility declines as she gets older, but did you know that men’s fertility also decreases with age? Unlike women, who experience fertility decline as they approach menopause, men’s changes in their reproductive system are gradual and occur in the context of a lifelong process that some call andropause.
Like women, men’s fertility decline with aging can be due to problems with the way their ovaries function, but they also experience changes in the quality of their sperm. A man’s sperm can become abnormal in shape (morphology) or movement (motility), which makes them less likely to fertilize an egg and lead to a healthy pregnancy.
A baby girl is born with about one million eggs in her tiny ovaries, but by the time she reaches puberty, there are only 300,000 remaining. These are the only eggs she will ever ovulate, and the rest of them are lost through a normal physiological process called atresia.
At around age 40, a man’s sperm begins to decline in quality, but there is no one-size-fits-all timeline for when a man’s sperm will become too old to fertilize an egg. It depends on the individual’s overall health, lifestyle and medical history, as well as genetics. In general, though, a man’s chances of becoming a father increase through his early to mid-forties, then begin to plateau.
Age at Sperm Quality Decline
Men are more fertile in their 20s, and their fertility continues to decline as they age. While there doesn’t appear to be a definitive one-size-fits-all timeline for when male sperm becomes too old to be useful, it depends on several factors including overall health, lifestyle and medical condition.
The World Health Organization has set semen parameters that are benchmarks for healthy sperm, including count, morphology (shape) and motility (movement). Although a man’s fertility can theoretically continue until his death, a measurable decline in sperm quality typically begins around the age of 35.
A study examining semen parameters in men aged 16.5 to 72.3 years found that ejaculate volume, sperm concentration and percentage of sperm with normal morphology did not decline until the age of 44. Sperm motility started to decrease after this point, and the count began to fall from age 50 onwards.
As a result, it is possible for men in their 30s, 40s and beyond to still conceive children, though a higher number of infertile couples is on the rise. However, it’s important for men to seek out a doctor for a full semen analysis and sperm count so they can make the best decisions about their future family planning needs. A sperm analysis can also reveal whether there are any abnormalities in the sperm DNA that could lead to future health conditions in their offspring, such as autism spectrum disorders, urogenital or cardiac defects and chromosomal diseases.
Age at Fatherhood
Men never stop producing sperm, but their fertility does decline as they age. This decline is much slower than the female fertility decline, but it still has an effect.
When a man is ready to father a child, the hypothalamus releases gonadotropin-releasing hormone, which stimulates the anterior pituitary gland to produce luteinizing hormone and follicle stimulating hormone. These two hormones travel through the blood to the testes and encourage sperm to form. Once sperm have formed, they move to the epididymis, which is a duct behind the testicles that stores and carries sperm. Once sperm are in the epididymis, they can join with fluid from the seminal vesicles to make semen. Semen is then emitted through the penis, and the sperm enter the vagina.
In general, a man’s sperm count and sperm quality decline with age. However, a man’s sperm is still capable of fertilizing an egg and giving birth to a healthy baby.
The oldest father to naturally conceive and give birth was a 96-year-old man from India. This is an incredible feat, but it shows that the body can produce sperm into old age and still father a child. However, a man’s ovarian health will also be a factor in his ability to father a child. For this reason, it is important for men to eat healthy, exercise, and take supplements that support a healthy reproductive system.