How and why is cryopreservation( freezing) of sperm done?

Methods Cryopreservation is the only effective way to preserve the biological material used in vitro fertilization( IVF).This method allows to preserve the structural and functional well-being of male sex cells carrying genetic material.

In medical practice, the so-called sperm banks are actively used, under which conditions the preservation and storage of biomaterials are carried out.

Fig.1 - This is what the sperm bank looks like - a store for frozen spermatozoa.

Indications

Detailed scientific studies of cryopreservation, allowed to expand the range of indications for the use of this procedure. In addition to IVF, artificial freezing of semen is indicated in such cases:

• Before starting therapy for malignant neoplasms. Antineoplastic treatment involves the use of chemical and radiation methods that have a negative impact not only on cancer cells, but also on the body as a whole. The first under the chemical and radiation strike fall quickly dividing cells, whose representatives are the precursors of spermatozoa. In order for a man not to lose the opportunity to continue his family, he is recommended to use the service of cryopreservation of germ cells;
• Before surgical intervention on the organs of the reproductive system. If a man has decided to resort to the surgical sight of contraception( vasectomy), it must insure themselves with the help of artificial freezing of semen;
• If there is a high risk of injury to the external genitalia. This risk is faced by men professionally engaged in sports;
• In case of spinal cord injury. This type of injury entails a violation of sexual function. With disorders of ejaculation, a man can hedge by freezing semen.

Indicators thawed biomaterial

After thawing canned semen, medical experts estimate biomaterial for several indicators. These indicators will be displayed in the form of a table.

degree of survival of germ cellsIs sufficient for the in vitro fertilization of a female ovum. Duration of storage of frozen semen should not exceed 3-4 years .With each subsequent year, there is a drop in the efficiency of the biomaterial.

Read on: How many spermatozoa live in different environments?

Preparing for the

Before sampling the semen, the male is recommended to undergo a screening. These activities guarantee the freezing of high-quality biomaterial. The list of mandatory diagnostic activities includes:

• Test for viability of spermatozoa under low temperature conditions( cryotest);
• Urethral smear for latent infections, sexually transmitted infections;
• Laboratory tests for syphilis, HIV infection and hepatitis;
• Investigation of quantitative and qualitative composition of seminal fluid( spermogram);
• Immunological analysis for herpes simplex virus.

3-4 days before the procedure, a man should refrain from sexual intercourse and masturbation. In addition, a couple of days before the proposed collection of biomaterial, a man is recommended to avoid excessive emotional and physical exertion, alcohol and tobacco consumption. In case of taking any medications, you should inform the medical specialist responsible for the process of freezing the ejaculate.

Technique of freezing

The procedure for cryopreservation of male germ cells is conventionally divided into several stages. The number of stages depends on the chosen method and the degree of equipping the medical institution. Pre-preparation of the ejaculate for freezing consists of the following stages:

• A sample of seminal fluid is placed in a special incubator to give a more fluid consistency;
• Further, centrifugation of the ejaculate is carried out in order to obtain a pure fraction of spermatozoa;
• The resulting portion of male germ cells is aged in a cryoprotectant at room temperature for 10 minutes;
• Medical specialists prepare freeze tanks containing the necessary marking( donor's name, date of freezing, card number);
• The final stage of preparation is to fill the prepared containers with a clean fraction of germ cells.

Having carried out training, medical specialists are moving to direct cryopreservation of spermatozoa. This manipulation consists of consecutive stages:

• Primary cooling of the material to a temperature of +4 degrees in the freezer at -20 degrees;
• Freezing of germ cells with liquid nitrogen. The freezing temperature is -79 degrees. The duration of the process is 120 minutes;
• The final step is deposition, which is characterized by the transfer of containers with germ cells into a Dewar vessel with a temperature of -196 degrees.

Fig.2 - Conducting the procedure of cryopreservation of sperm.

Defrosting of germ cells

Most male germ cells are viable. Shock freezing does not have a negative impact on their structural and functional state. In specialized medical centers, various methods of defrosting biological material are used:

• Use of the reverse-freezing technique in freezing plants;
• At room temperature;
• By means of a water bath( defrosting temperature is +37 degrees).

The main rule for preserving a large number of viable spermatozoa is to maintain a defrosting rate that corresponds to the rate of freezing. After removing the container from the germ cells, they are thawed by one of the listed methods.

FAQ on cryopreservation of sperm

Is it possible to freeze semen by yourself?

No. Independent cryopreservation of male sex cells is not possible. Such experiments did not result in a positive result, since the structural and functional state of spermatozoa can be preserved only when frozen with liquid nitrogen.

How much frozen sperm are stored?

The optimal shelf life of frozen semen is 3 years. After this period, spermatozoa begin to gradually lose fertilizing ability. However, some sources claim a successful conception, for which sperm stored for 21 years was used. How far this case could not be verified truthfully.

Does frost affect the success of conception?

Modern cryopreservation technologies allow this procedure to be performed with minimal loss of viable spermatozoa.

Are there other methods of storing ejaculate?

An alternative to cryopreservation of germ cells is the method of containing spermatozoa in a salt-free aqueous solution of glucose. Such cells do not undergo freezing. The technique is used for short-term expectation of fertilization.

Where is cryopreservation performed?

It is possible to freeze male germ cells in a special sperm bank located separately or in another medical institution.

What is the cost of the procedure?

Depending on the region of residence and the price policy of the medical institution, the average cost of this service is 5000 rubles. Next, you pay an annual fee for storage of the material.

See video about cryopreservation of sperm

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