Monthly Archives: Август, 2018

WHAT IS SPERM DNA FRAGMENTATION TEST AND WHICH PATIENTS IS IT FOR?

In our previous article, «Sexual Abstinence in Men and Pregnancy«, we mentioned that long abstinence in men is associated with an increase in spermatozoa with fragmented DNA. But what exactly does DNA fragmentation mean? Who is the test useful for?

Standard semen analysis gives information about the three main parameters,

evaluating male fertility (concentration, motility and morphology) but it does not give any information about the percentage of spermatozoa with DNA fragmentation. The integrity of sperm DNA can be disturbed as a result of exposure to chemicals, smoking, high temperature, free radicals, produced as a result of normal metabolism, and other factors. A high percentage of DNA fragmentation is associated with a lower fertilization rate, worse embryo quality and higher incidence of miscarriage.

Indications for sperm DNA fragmentation test

The test is usually recommended for men with normal parameters who together with their partner suffer from unexplained infertility and have undergone several unsuccessful IVF cycles or pregnancy losses.

The DNA fragmentation test could also be done for men with deviations in the main sperm parameters, provided that they have enough spermatozoa. Even though the cause of infertility is known in male factor patients, the DNA fragmentation test is done if the treating physician requests it. This usually happens again in the case of more than 3 unsuccessful IVF cycles or multiple pregnancy losses. Another reason is professional hazards such as chemical or heat exposure.

If an increased percentage of spermatozoa with fragmented DNA is found, lifestyle changes could be helpful. As well as avoiding the professional hazard, those include consuming antioxidant-rich foods and leading a generally healthy lifestyle without too much aerobic activity.

If you think the DNA fragmentation test may be useful in your case, discuss it with your treating physician.

Those of you who have been through IVF know that on the day of the procedure the male partner has to have between 2 and 5 days of sexual abstinence. The same is true if the man is going for semen analysis. What actually happens in the male body in those 2 to 5 days? Is there a connection between sexual abstinence in men and pregnancy rate?

Unlike ovulation in women, which is cyclical (usually once every 28 days), spermatogenesis is a constant process. Spermatozoa are stored in the epididymis and during ejaculation mix with secretions from the male accessory glands. These include mainly the prostate and seminal vesicles. It is logical to assume that the longer the period of sexual abstinence in a man, the more sperm will accumulate. However, the World Health Organization (WHO) reference values for sperm concentration, motility and morphology were determined for 2 to 5 days of abstinence. The reason is that this abstinence period is within physiological limits. Outside those limits the sperm accumulated in the epididymis could overflow and is flushed with urine.

There is some evidence that abstinence longer than the mentioned above could result in deterioration of sperm quality, in spite of the fact that semen volume and sperm concentration are usually higher. This deterioration is thought to be due to an increase in DNA fragmentation. It is hypothesized that when sperm are stored in the epididymis for long periods of time, they are exposed to free radicals, which increase the percentage of sperm with fragmented DNA. As the smallest cell in the human body with a very small amount of cytoplasm, the spermatozoon has limited mechanisms for neutralization of free radicals. Therefore, it is not recommended for spermatozoa to be left for a long time in the epididymis or once they are ejaculated.

According to a study published in 2017 in the prestigious American journal Fertility and Sterility, IVF cycles in which the male partner had less than 5 days of abstinence have on average higher pregnancy and live birth rates.