Did you know…?
The position of the testicles outside the body causes their temperature to be about 2-3 °C below the body temperature. This is a prerequisite for optimal sperm development.
Focus on men
Male fertility
- Duration of sperm maturation process: approx. 64 days
- Control centre: hypothalamus in the brain
- Release of the GnRH hormone serves as a signal for the pituitary gland
- The pituitary gland reacts by releasing FSH and LH
- Two important types of cell are found in seminiferous tubules: Leydig and Sertoli cells
- LH stimulates Leydig cells in the testicular tissue to produce testosterone
- FSH stimulates the Sertoli cells with testosterone to mature the existing immature sperm cells
- Mature sperm cells enter the epididymis from the seminiferous tubules and are stored in the ducts of the epididymis
- Within 14 days, the mature sperm cells in the epididymis continue their journey towards the vas deferens
- Semen ejaculation: sperm from the epididymis is pushed out of the body via the vas deferens and the urethra
- Complete activation of the sperm: the sperm cells obtain their motility only at the point of ejaculation and the addition of the various secretions (seminal plasma)
- Semen ejaculation may contain up to 400 million sperm
- The sperm cells are only fully fertile and ready to merge with the egg after the capacitation and acrosome reaction
Did you know…?
In assisted fertilisation, these activation steps can now be successfully carried out artificially.
Sperm count in the ejaculate – what is normal?
According to the WHO, a healthy man should produce at least 15 million sperm per millilitre of ejaculate. And the ejaculate volume should be at least 1.5 millilitres. Of these sperm, 4% should be normally shaped and 40% should have good motility. If these values are lower, fertility is impaired. However, even if the sperm cells look normal, they may not be physically fertile. This large volume is necessary because many sperm cells die off on the way to the egg cell or are unable to fertilise it for other reasons.
Possible causes of infertility in men
Unfortunately, it is not always possible to clearly determine the cause of infertility. In 15 to 30% of couples, the cause remains unknown.
- Hormonal imbalances (thyroid diseases, diabetes, abuse of hormonal anabolic steroids)
- Disorder of sperm formation (too few or defective sperm cells)
- Increased testicular temperature due to chemotherapy, medication, radiation, fever, varicoceles
- Interruptions to sperm transport (blockages in the vas deferens mean that sperm cannot enter the woman’s body). Causes include inflammation, sexually transmitted diseases, injuries, scarring, tumours, suppression, metabolic diseases, etc.
- Congenital malformations of the genital organs (high testicles, absence of one or both testicles, malformations of the testicles)
- Immunological dysfunctions: the body produces antibodies that target the sperm cells.
- Erectile dysfunction (impotence) caused by diabetes, medication, addictive substances, nerve damage, stress, etc.
- Severe psychological/physical strain
- Alcohol
- Smoking
- Drugs
- Medication
- Anabolic steroids
- Being overweight
- Environmental toxins
Age also plays a role, but tends to be felt later than for women and less severely. The testicles become smaller and softer, the quantity and quality of sperm decreases. Chromosomal changes, i.e. disorders of genetic information, occur more frequently. Externally, however, hardly anything will look different. Especially if the libido and the ability to achieve and maintain an erection are maintained.
What does … actually mean?
… azoospermia? The sperm cells are completely absent from the ejaculate.
… oligozoospermia? The number of sperm cells in the ejaculate is reduced.
… asthenozoospermia? The sperm cells in the ejaculate have limited motility.
… teratozoospermia? The sperm cells are malformed.
Investigations for men
A specialist will perform a series of comprehensive tests to identify fertility disorders. In this case, it will be an andrologist or a specialist in reproductive medicine.
- Questions about:
- previous/current illnesses (e.g. mumps, diabetes, thyroid dysfunction, sexually transmitted diseases)
- hereditary diseases in the family
- medications taken
- special therapies such as radiation or chemotherapy, injuries to the genitals, surgical procedures (e.g. hernia)
- lifestyle (alcohol, smoking, exercise, frequency of sexual intercourse)
- Questions about:
- Determination of any testicular anomaly (position, size, shape) or disease
- Blood tests (including hormone tests)
- Analysis of seminal fluid and sperm cells (spermiogram)
- Sperm function tests and urinalysis
- Ultrasound examination of the testicles or prostate gland
- Biopsy to examine testicular tissue
- Genetic investigation for the detection of hormone/receptor polymorphisms
Infertility in men – is it even an issue?
Worldwide, male sperm quality appears to be steadily deteriorating. The reasons are unclear. In 40% of cases of involuntary childlessness, the problem is male infertility. According to the Swiss Federal Statistical Office, male infertility was the most common reason for IVF/ICSI treatment in Switzerland in 2013, being responsible for 38% of cases.
