Effect of temperature on sperm motility and viability

This is an automatically translated article.

When semen samples were kept at 37°C, spermatozoa lost motility and viability. If kept at 4°C, they are still viable but lose mobility due to heat shock. The best semen storage temperature to preserve sperm motility is 20°C.

1. Data from the experiment

The experiment was performed on 42 fertile men who voluntarily requested a vasectomy. Semen samples were collected and stored at 4, 20 and 37°C. Mobility and viability were analyzed after oil immersion and pH for 3, 6, 12 and 18 h. Specifically:
When semen was kept at 20°C, the decline in motility was negligible after 12 h. However, semen motility decreased significantly when kept at 4 or 37°C, with the worst being at 4°C. Thus, mobility decreases with time at 20 and 37°C, but at a significantly higher rate at 37°C (where peristalsis halves after 12 h).
In these experiments, viability was assessed by eosin-nigrosin staining and could not be recovered by reheating semen. The results were as follows:
Sperm viability was as reduced as motility at 20 and 37°C. Survival was best preserved at 4°C despite loss of mobility. Specifically, at 4°C, motility was almost absent after 6 hours, but sperm remained viable after 18 hours. At temperatures higher than 4°C, the immobilized spermatozoa die due to the proliferation of bacteria, mainly gram-negative bacteria such as Esch. coli and Proteus. Occasionally, gram-positive enterococci have also been identified. At 37°C, semen is remarkably acidic. The marked increase in bacterial numbers and decrease in pH at 37°C explained the decrease in motility and viability.
To determine the effect of bacterial growth on sperm motility, the experiment was repeated with the addition of antibiotics. Result:
No organism growth and no drop in pH, even at 37°C. Sperm in conditions with antibiotics retained motility at 20 and 37°C better. There was still a significant decrease in motility in samples kept at 37°C (body temperature), even when bacterial growth was prevented. What temperature do sperm live at? These studies have shown that it is best to keep semen samples at room temperature (20°C) between ejaculation and analysis. Samples kept at 37°C lose both mobility and viability. Samples kept at 4°C lost mobility due to heat shock but retained viability.

2. The ability of sperm to live in other environments

After ejaculation, if the sperm does not enter the woman's body but goes out into the environment, it can still survive, but the time is very short. Specifically as follows:
In the air When ejaculating into the air, clinging to surfaces such as bed sheets, paper towels, the floor... the life time of sperm is only a few minutes, with sperm conditions. The semen is still wet and the adhesion surface is free of chemicals. Once the semen has dried, the sperm is no longer viable.
Note, if the sperm near the vagina has enough moisture and warmth, it can live for about 20 minutes. Therefore, if there are effects that cause sperm (which have been exported to the environment) but can move to the vagina, there is still the possibility of conception.
In condoms Sperm can live up to 24 hours in condoms, depending on the material and the storage temperature of the condom. Specifically, if using condoms with spermicide, they will die in a few minutes. Otherwise, sperm can live for 15-20 minutes until the semen is no longer at the right temperature and state.
In case the ambient temperature is right, the condom is tightly tied so that the semen does not dry out, the sperm can live for several hours. But in general, most condoms have lubricants and preservatives, so the life time of sperm is not too long.
In hot water sperm live at what temperature? Men's scrotal temperature usually fluctuates at 43°C, which is the ideal level for sperm to live and develop. If ejaculated into warm water with the same temperature, sperm can live for several minutes. In case of ejaculating into hot or boiling water, the sperm will die immediately.
Sperm Freeze Men can choose to freeze sperm to preserve the ability to maintain the breed for many years. When cooled at -196°C, all biological activity of sperm ceases to be effective. Studies show that frozen sperm can last forever. Babies born from frozen sperm can still develop normally, both physically and intellectually.
Sticking to the hand Sperm are not able to move on the skin. They must be in direct contact with the vagina before they can travel to the uterus and fallopian tubes. But sperm can live for several minutes on the inner hand if not wiped away. So, if enough sperm on the fingers is inserted into the vagina, there is still a chance that pregnancy will occur.
In the pool Sperm life in the pool is usually only a few seconds because the pH of the water in the pool is different from the pH inside the vagina.

3. Other factors affecting sperm viability

In addition to laboratory temperature, the viability of sperm mainly depends on the following natural factors:
Age Sperm of men aged 20-40 years have the most vitality. After the age of 40, the vitality of the sperm decreases and many malformed sperm appear. After the age of 60, about 80% of sperm can be deformed. Therefore, men should give birth during the period of peak sperm vitality to ensure the ability to conceive.
Drinking alcohol, smoking People who regularly smoke cigarettes will have a marked decrease in sperm quality, and an increase in the rate of malformed sperm. Besides, long-term alcohol consumption also affects and causes testicular atrophy, as well as reduced sperm quality. Therefore, men should limit the use of stimulants to avoid affecting sperm quality.
Outside temperature The habit of regularly wearing tight pants, sauna, soaking in hot water or putting a laptop on your lap,... will cause testicle temperature to rise, reducing the growth and vitality of the testicles. sperm .
Exercise Obese men have an increased temperature in the groin, thereby affecting the development of sperm. Moderate exercise, creating hormonal balance in the body, especially male sex hormones, can help increase sperm vitality.
If you and your partner are planning to become pregnant, you need to learn about sperm health, temperature and viability. This study will help men eliminate the factors that affect sperm quality and how to produce good sperm and stay healthy.
Currently, at Vinmec International General Hospital, there is a semen analysis test as well as a reproductive health checkup for men. If you have fertility problems, you can visit Vinmec directly and receive expert advice from doctors.

Please dial HOTLINE for more information or register for an appointment HERE. Download MyVinmec app to make appointments faster and to manage your bookings easily.

References: pubmed.ncbi.nlm.nih.gov, sciencedirect.com