Infertility can be caused by poor sperm quality. The Danish men's sperm count is one of the lowest in Europe. Despite a slight improvement in recent years, sperm quality is generally poorer than 50 years ago*. Less than one in four has an optimal sperm count and 15% have a sperm count that is so poor that they will have difficulty making a woman pregnant without fertility treatment.
Although only one sperm cell is necessary to fertilize one egg, the number of sperm cells are relevant for fertilization ability. Men with a high sperm count (more than 40 million sperm cells/ml) are more likely to impregnate their partner than men with a lower sperm count.
The poor sperm quality may be due to several factors:
- Testicular dysgenesis syndrome (TDS): Disruption of the male reproductive system in the embryonic stage. May causes increased incidence of testicular cancer, poor sperm quality, cryptorchidism and hypospadias in men and boys.
- Environmental factors: A number of environmental chemicals are suspected to be risk factors for male reproductive disorders - this is shown in animal experiments. For example, alkylphenols (soaps, plastics), bisphenol A (soda bottles of hard plastic), parabens (cosmetics, food), chemical UV filters (sunscreen, outdoor plastic), natural and synthetic estrogens.
- Genetic factors. These may be chromosome aberrations or damage on the Y chromosome ("micro-deletions").
- Tobacco smoking can impair sperm quality.
- Fever, disease and certain medications are also known to impair sperm quality, often only temporarily. The sperm quality can be reduced for up to three months after an episode with fever.
The sperm sample
The sperm sample can be analyzed by assessing sperm count and mobility. Fertility Laboratories carry out these analyzes both before and after a density-gradient centrifugation. The sperm is separated, so that the best sperm cells remain. After this test, you can expect the following answers:
- The sperm sample is good and likely to have normal fertilisation potential and may therefore be used for all types of treatment, insemination, IVF and ICSI (more than 2 million "good" sperm cells).
- The sperm quality is less good, and can be used for ICSI
- There are no sperm cells (azoospermia), further investigation and information is needed
In cases of very low sperm count, further examinations are advised to find an explanation. This may include hormone tests, chromosome analysis and ultrasound of the testicles.
If the sperm sample shows no sperm cells, in some cases there is still sperm cells in the testicles. The probability is assessed in each case. In this situation, it is possible to extract sperm cells directly from the testicles, a method called TESA (testicular sperm aspiration). By TESA relatively few sperm cells are retrieved, so it is always necessary to perform ICSI, when sperm cells are obtained by TESA.
TESA is also an option for fertility treatment in couples where the man has had a vasectomy. In this situation, it is always necessary to make vitro fertilization with ICSI.
*Jørgensen N et al. Human semen quality in the new millennium: a prospective cross-sectional population-based study of 4867 men. BMJ Open. 2012 Jul 2;2(4).
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If you have been trying to achieve a pregnancy for more than one year (or less if you are over 37 years of age) without success, we recommend you book a consultation.