Definition of Male Infertility
Definition of Male Infertility
According to the WHO, male infertility is defined as the inability of a man to father a child within one year of regular, unprotected intercourse (during the woman's fertile days).
Male fertility disorders
Disorders of sperm production
The following fertility disorders can be identified through a semen analysis (spermiogram):
- Reduced total sperm count: Oligozoospermia
- Reduced number of motile (moving) sperm: Asthenozoospermia
- Reduced number of normally shaped sperm: Teratozoospermia
Disorders of the transport pathways
The male testes produce sufficient sperm; however, these sperm are blocked from transport due to adhesions, hardening, or blockage of the seminal ducts.
The result: a complete absence of sperm in the ejaculate.
Causes of Male Infertility
Causes of impaired male fertility are diverse. Various pre-existing conditions - often from childhood - infections, inflammations of the testes and epididymis, bladder, or prostate can lead to male infertility.
Undescended Testicles (Cryptorchidism):
During childhood, if the testicles do not descend into the scrotum but remain in the abdomen or groin area, sperm production can be permanently damaged if this condition is not corrected in time.
Infections: A childhood mumps infection (mumps orchitis) can cause inflammation and hardening of the testes, which is associated with significantly reduced sperm production.
Varicocele (Testicular Varicose Veins):
The spermatic cords are surrounded by a network of veins. If these veins become enlarged, it is called a varicocele. This mostly affects the left testicle due to poorer blood drainage on that side. The increased heat caused by blood pooling can negatively affect fertility.
Hormonal Disorders:
Hormonal imbalances can also cause infertility in men. Hormones especially important for sperm production include testosterone, FSH, and LH. Deficiencies in these hormones can impair male fertility.
Genetic Defects:
Genetic disorders include Klinefelter syndrome, which leads to reduced male hormone secretion and decreased sperm quality, as well as deletions - loss of genetic information on the Y chromosome, which is responsible for male sex determination. Genetic defects can be identified through blood tests.
Additional risk factors include stress, dietary habits, overweight, certain medications, as well as alcohol and nicotine consumption, and environmental factors.
Diagnosis
In cases of infertility, women are often examined first, with men being tested later. However, a timely examination of the man is equally important.
The diagnosis of fertility disorders in men is carried out by a specialist in reproductive health, known as an andrologist. Andrology is a subfield of urology. The following examinations and assessments provide insight into male fertility:
- Detailed medical history including previous illnesses and lifestyle factors
- Physical examination of the genital organs
- Ultrasound examination of the testes
- Hormonal diagnostics (FSH, LH, prolactin, and testosterone)
- Semen analysis (spermiogram) to assess the quality and quantity of sperm cells
- If necessary, testicular biopsy
Hormonal Diagnostics
Hormonal analysis can also be relevant for men when investigating infertility. Especially with reduced sperm quality, hormone testing is recommended. Symptoms indicating hormonal imbalance may include fatigue, loss of vitality, weight gain, and reduced performance. Hormone levels are measured via blood samples.
Semen Analysis (Spermiogram)
The spermiogram is the most important diagnostic tool to assess male fertility. It is a microscopic analysis of the ejaculate and provides information on sperm quality, sperm count, and sperm concentration. Additionally, the volume and pH of the ejaculate are determined.
The ejaculate is collected by masturbation after an abstinence period of two to seven days under sterile conditions, ideally in a laboratory on-site or no later than 30 to 60 minutes after collection. At least two spermiograms within a 4 to 12-week interval are recommended, as sperm count and quality can fluctuate significantly.
Parameters of Sperm Quality
Sperm must be capable of reaching the egg. Key parameters include:
Sperm count: Indicates sperm production and the number transferred during intercourse.
Sperm morphology: Examines sperm shape, focusing on the head, midpiece, and tail. Most sperm are not perfectly shaped and may have multiple heads or tails. According to WHO, 4% normal morphology is considered the threshold for normality.
Sperm motility: The ability to move is crucial for traveling through the female reproductive tract. Forward progressive movement is especially important.
WHO Criteria for Semen Analysis
The World Health Organization (WHO) has established reference values for semen analysis, updated most recently in 2021:
Ejaculate volume: ≥1.4 ml
Sperm concentration: ≥16 million/ml
Total sperm count per ejaculate: ≥39 million
Progressive motility (forward-moving sperm): ≥30%
Total motility (progressive and non-progressive): ≥42%
Morphology (normal-shaped sperm): ≥4%
If results fall outside these reference values, treatment is necessary. Consult your specialist to discuss the next steps. More information on therapy can be found here: [LINK to therapy]
DNA Fragmentation
The sperm's role is to safely deliver the father's genetic material to the egg, enabling healthy embryo development. DNA breaks or damage in sperm genetic material can prevent cell division and embryo development. Even if a spermiogram is normal, fertility may be impaired. A spermiogram does not detect DNA fragmentation. Specialized tests such as the TUNEL or SCD test can analyze sperm DNA integrity using a semen sample.
Currently, no standardized reference values exist, but 15 to 20% of sperm with mild to moderate DNA fragmentation is associated with reduced fertility. If DNA fragmentation is detected, lifestyle modifications are recommended.