"Freezing the Future: Preserving Eggs, Sperm, and Embryos for Tomorrow"

Cryopreservation procedure provides the facility of freezing of eggs, sperms, or embryos to be used later. In IVF generally, three techniques of cryopreservation are followed.

Oocyte cryopreservation or Egg Freezing

Oocyte cryopreservation provides you with an opportunity at any desired point in the future to utilize these frozen eggs. If you feel prepared for a pregnancy, then you can use these preserved eggs to obtain a healthier pregnancy. This reduces your concern over chromosomal abnormalities that otherwise increase with age, especially when you are 35 or older years. Frozen oocytes can be thawed and then combined with sperms in the clinical lab. If all goes well, and the egg gets fertilized, then the resulting embryo is implanted in the uterus as part of the IVF cycle.

Sometimes, with the oocyte cryopreservation technique, you can choose to preserve some of the eggs harvested while using IVF to conceive a child. This might be so in case you want to have another child at later dates. You can also donate them to women who cannot bear children. Oocyte cryopreservation further empowers women to reserve her eggs, who are on medication treatment like cancer therapy which may adversely impact her capability of producing eggs.

Procedure

Oocyte preservation involves the following.

• Ovarian stimulation- Medications will be administered to stimulate your ovaries to produce multiple eggs.
• Extraction of Eggs- It is done at the hospital, and you'll be sedated. Generally, this procedure is done by a transvaginal ultrasound wherein the doctor puts a probe inside the vagina to look for the follicles. Thereafter, a needle is inserted, and the eggs are sucked out from the follicles. You are likely to take out approximately 15 eggs in one cycle, and you are likely to feel some little pain and cramping post the process.

• Freeze - Eggs retrieved from liquid nitrogen are cooled to the sub-zero level such that one freezes them for later use. Vitrification is another rapid freezing technique which primarily dominates the process involved in freezing eggs. These need the application of cryoprotectants during this cooling treatment for avoiding the formation of ice crystals. Slow-freezing is also possible. However, vitrification or rapid freezing is considered to be the more efficient technique as it eliminates all risks of damage to oocytes and better survival rates are ensured with freezing and thawing the eggs.

Egg cryopreservation allows you to have a perfect start possible when you think that you are ready for pregnancy.

Cryopreservation of Semen

Semen freezing, otherwise known as sperm cryopreservation is the procedure wherein sperms are frozen for future use. This is a way of preserving male fertility who are to undergo treatment that may result in possible infertility; such as chemical treatment with certain radiotherapy or prostate/testic surgery. You can be induced to freeze sperms whenever you are exposed to chemicals exposure or radiation. In that regard, sperm freezing is applicable and falls under the lists of utilization of the above sperm banking process. Procedure The semen sample is taken in a sterile dish within a laboratory and assessed about volume, viscosity, motility, count, and all other aspects. Cryoprotectants are incorporated to inhibit ice crystallization from happening during freezing. There are two methods for cryopreservation. Slow freezing: It takes two to four hours in the cooling of sperms. Then the sample is put in liquid nitrogen at minus 196-degree celsius. Shallow freezing: In this process, aseptic samples are put directly in liquid nitrogen within eight to ten minutes. Due to reduced water content, sperms have fluidic membrane; hence they are quite insensitive to damage once after cryopreservation.

Embryo Cryopreservation

The female will be given medication that would result in the maturation of some eggs. The eggs recovered from the process will be given a chance to be fertilized by sperms from the husband. The resultant eggs or embryos are put into cryopreservation approximately three to five days after they become fertilized. In slow freezing, embryos are frozen over two to four hours, as discussed earlier. In rapid freezing, embryos are directly put into liquid nitrogen at subzero temperatures. If you are not prepared to conceive but still want to save the option for later, there is cryopreservation. Second, if you are an IVF candidate or one who has failed a round of IVF cycle then cryopreservation will become a boon to help you counter infertility. In case, you are in search of cryopreservation, there are also some things that you may want to keep in consideration. To determine whether cryopreservation suits you, your doctor may recommend that you begin by undertaking a fertility test to identify your fertility factors.

Risks Involved in Cryopreservation

Cryopreservation and IVF are safe procedures. Most of the research studies have revealed that cryopreservation of sperms, eggs, or embryos is not linked with any adverse effects. Children born with cryopreserved embryos or oocytes do not have any congenital disability or birth defect.

The main objective of embryo freezing is to preserve it for future use. That, therefore means that this embryo should be subjected to conditions that do not allow it to abort. The Steps involved in freezing or cryopreserving an embryo.

Embryo selection

The woman is medically induced to producing more eggs in the IVF process. Also, the man will produce more sperm cells. When the two are combined it not a rare thing to have several embryo formations normally from one to four embryos are usually placed inside of the woman for implantation but the rest are discarded in the process. In this case, one is going to select the heathiest embryo or embryos which are going to be preserved for possible use later.

Dehydrate

The selected embryo can't be frozen directly unless the water content inside the cells is filled in. If it is kept frozen, water content inside the cells freezes and crystallizes. The formation of a crystal may cause swelling of the cell which leads to the rupture of the cell and death. Cryo protectants are used in order to fill in the water content inside the cells so that this is prevented.

Freezing Embryo

The embryo is cooled to 20 degrees Celsius, then frozen after the water content has been removed. There are two ways of doing this.

Slow freezing

They are embedded in the straw plugged with sterilized bearings so that the embryos are not injured. Not to let it further age and get harmed, step temperature reduction of the tubes is done beginning at 20° down to -7° up to -35° after embedding inside the embryos. Then, a straw/tube from the freezer is taken out, placed in a holder having liquid nitrogen held at -196° Celsius.

Egg vitrification

This is much shorter compared to the process. This process cryoprotects embryos which freeze much faster, and the embryos don't let the water molecules inside the embryos crystallize. Embryos frozen are dropped into liquid nitrogen. The process is not very frequent due to the high demand for the grade of cryoprotectants, and also the liquid nitrogen is easy to contaminate.

Of the chances of use again -

This term that describes defrosting is known as thawing. When there are needs for the embryos, they will first be brought out from the liquid nitrogen tank and then into a water bath with temperature rise in a gradual scale. When this happens, cryoprotectants start leaving the embryo. Dilution should therefore occur in a gradual scale in an attempt to neutralize the rest effects caused by the cryoprotectants. It is never too late to have help from the advanced reproductive drugs and technology, if there are problems in pregnancy. For more information and choices, one may get advice from a healthcare professional.