In this webinar, Elisa Moya Gutiérrez, Embryologists of UR Vistahermosa, Alicante, Spain, has discussed sperm quality, how age can affect its quality and what can be done to improve its quality.
Infertility is defined as the inability to achieve pregnancy after 1 year of unprotected sexual intercourse. This impacts 15% of couples of reproductive age. The main factor is responsible for up to 40 to 50% of the cases of sterility in the couple. Therefore, concerns about semen quality have increased, in recent years, due to the decline in semen parameters, according to World Health Organization (WHO). Although this does not imply sterility, it results in achieving pregnancy. Multiple causes can affect seminal quality, including the proper formation of the sperm, called spermatogenesis, its transport through the male genital tract as well as the fertilization process. The most common cause associated with men sterility is varicocele, which is the swelling of the veins inside the scrotum, an infection in the seminal tract, immunological pathology, developmental anomalies, endocrinological pathology, mechanical causes, such as disturbance in the erection or the ejaculation, genetic causes and toxins, drugs, labour factors and advanced paternal age.
The basic test done on the semen is called a seminogram, and it is a study of seminal quality. The volume of the semen is analysed, and other parameters such as concentration should be a minimum of 15 million per millilitre, sperm motility, which should be more than 32%, vitality (more than 58% of life sperm) and morphology (there must be at least 4% of sperm with normal morphology).
However, sometimes further analysis is required. In those additional tests, we can include, diagnostic capacitation, which measures progressive motile sperm count. Another test is called Sperm DNA fragmentation, which measures breaks or lesions in the genetic material of the sperm, the greater the number of lesions, the lower integrity of the genetic material and the lower the chance of pregnancy to occur. Sperm FISH tests detect genetic abnormalities.
It has been scientifically proven that some lifestyle factors such as obesity, smoking, drugs and chemicals can influence seminal quality.
Obesity occurs when BMI is more than 30 kg/m2. Obesity is associated with various health problems, such as cardiovascular, diabetes, and hypercholesterolemia, but it also affects fertility because obesity is associated with hormone changes that can lead to a reduction in seminal quality. Testosterone is one of the hormones involved in spermatogenesis, and it has been found that when a high amount of fat is present, testosterone levels decrease, and estradiol levels increase. In addition, a low level of testosterone may lead to problems of erectile dysfunction and consequent difficulty in naturally achieving pregnancy.
Couples with low semen quality or ejaculatory problems can use a technique called ICSI (Intracytoplasmic Sperm Injection). Recent studies have analysed the results of this type of treatment by comparing the results of treatments where the male has a normal body mass index versus the man who has a high body mass index and it has been found that overweight men may adversely affect the outcome of the treatment. Therefore, obesity affects the outcome in patients who try to conceive naturally or go through treatment.
The link between smoking and semen quality has been widely demonstrated. It is associated with a decrease in spermatozoa count and the damaged DNA of spermatozoa. Cigarettes are mostly composed of nicotine, alkaloids, amines, ketones and many more toxic substances. These compounds have been detected in the seminar plasma because they cross the hematotesticular barrier and this influences the quality of the sperm directly. Recent studies suggest that tobacco increases DNA fragmentation. This increase may harm the natural fertilization process and also the IVF treatment result. It is also associated with a decrease in fertilization and implantation rates and an increase in embryo blockage and miscarriage rates.
The most harmful drugs for reproduction are the drugs used for cancer treatments. Chemotherapy and radiotherapy are very aggressive treatments for spermatogenesis, and depending on the type of the drug and the radiation dose, this effect may be definite or transitory. It’s essential to freeze the sperm for prevention at the time of diagnosis of systemic or oncological disease. Other drugs such as immunosuppressors, neuro drugs like antidepressants or antibiotics or neuroleptic drugs, as well as hormones. Anabolic androgenic steroids are synthetic derivatives of testosterone, and it’s been used by many sportsmen to enhance athletic performance and appearance without prescription. The adverse effects include problems with the liver, psychological or behavioural problems and also reproductive system problems because it harms spermatogenesis. At times, this effect is irreversible.
Recreation drugs such as marijuana, which is the most widely used recreational drug in the western world. Cannabis is a drug that depresses the nervous system, it contains the compound of a molecule of THC, which is a psychoactive compound and it harms the endocrine and reproductive system especially by decreasing sperm quality and testosterone levels. An investigation was carried out in Denmark in 2015 with 1 250 men aged from 18 to 28 years associated consumption with a decrease in sperm count of up to 29%. Those who additionally used other drugs and they saw a reduction in sperm count by up to 55%.
Another study carried out by the University of California revealed that cannabis modifies the movement of sperm within the female genital tract. That means that when sperm reach the female reproductive tract, it shows very low energy levels to perform the movement, especially at the final stretch when having a good contribution is essential to be able to cross the other side and fertilize it.
There is an increasing number of studies linking alcohol consumption to reducing fertility in both men and women. It may alter testosterone secretion and spermatogenesis. The European Association of Urology confirms that heavy alcohol consumption produces significant spermatozoon morphological changes, a decrease in seminal fluid volume, lower sperm concentration and sperm motility. It’s also been demonstrated that alcohol increases sperm DNA fragmentation, which decreases sperm quality and fertility potential. Alcohol incapacities the sperm’s ability to trigger the fertilized oocyte and embryo development.
Exposure to pesticides (farmers), radiation, heat, and glycol ethers (shipyards and foundries workers) also can be harmful to fertility. It’s
been documented that these physical agents are toxic to sperm, but further investigations are necessary before definite conclusions are reached on these factors. Also, the use of mobile phones, laptops, and wireless Internet technologies, such as Wi-Fi or 5G has increased concern about the effect on male fertility as these devices constantly emit electromagnetic radiation. This again can alter the male reproductive endocrine mechanism and consequently affect testicular functions. Exposure to mobile phones and electromagnetic radiation decreases sperm motility, and viability, and increases oxidative stress.
It’s also important to mention that paternal age can also make a difference. The average age of becoming a parent has increased in recent decades in western countries in parallel with the increase in maternal age. The importance of women’s age in reproduction is well known, whereas it’s not as well known in men. There is no universal definition for advanced paternal age, but it is mostly defined as being more than 45 years at the time of conception. The physiological ageing of the male reproductive apparatus can be manifested in various forms:
oxidative stress increases, which causes cell damage, including DNA damage
decreasing levels of testosterone reduces sperm mobility and volume
lower embryonic quality in assisted reproductive techniques (ART)
increased risk of psychiatric disease in offspring, such as TDH or Autism
increased risk of miscarriage
Sperm quality – ways to improve it
The most common factor that can benefit sperm quality is diet. Various studies have been carried out to determine how diet affects seminal quality. A proper diet should be varied, low in fat and of high nutritional value, rich in water, absent of toxic substances, and intake of natural products over processed ones. A diet rich in nutrients such as omega-3 fatty acids, and antioxidants, which eliminate the excess free radicals, such as vitamin E, C or D, beta-carotene, selenium, zinc, and folate are associated with an improvement in sperm quality.
Another important factor is physical activity. an active lifestyle. It keeps oxidative stress at low levels, reduces inflammation, and prevents obesity. It has been confirmed that sperm parameters are better in physically active men compared to sedentary men. Moderate training is associated with improvements in sperm DNA integrity in sperm quality, however, intense physical exercise can have the opposite effect and a decline in the quality of the sperm.
Fertility is not mathematical, this is a combination of factors that sometimes we can’t control, each case is unique, and before doing any tests or changing your lifestyle habits, it’s better to be advised by a specialist.