How to Know if Cryopreservation is Right For You


Not every couple who deal with infertility will need to undergo in-vitro fertilization, and not all IVF patients will need to worry about cryopreservation, the freezing, storage of sperm, oocytes, or embryos. For example, the embryo cryopreservation process requires high quality embryos at Day 3 of development, after the best embryos have been transferred to the mother. They can also be preserved at the blastocyst stage on Day 5 or Day 6, as long as development has progressed normally. Most embryos do not progress beyond Day 3 unless they are viable and likely to result in pregnancy.

Cryopreservation should be considered if you are younger than 35 years of age, and are generally healthy. Your OB-GYN or fertility specialist will be able to assess your viability for the procedure. For older patients, who not only produce fewer eggs with or without IVF treatment, but also require more embryos for transfer during a cycle, they are less likely to have the required abundance of high quality embryos for cryopreservation.

Embryo cryopreservation has tremendous benefits, however. Since more oocytes are exposed to sperm during each treatment cycle, IVF pregnancy rates are increased. Currently, embryo cryopreservation is considered as a standard treatment as well as an essential technology in most laboratories. Embryo cryopreservation can maximize success rates, decrease the occurrence multiple pregnancies, and lower the costs of future treatment. This mitigates the need for further hormonal stimulation cyclesand minimizes having to waste embryos.

Sperm cryopreservation has been a common practice for several decades.As a result, the technology for preserving and storing sperm is well defined. At many centers, frozen sperm from sperm banks and other tissue banks are stored until the patient is ready to use them. Since sperm tolerate the freezing process well, the survival rates for healthy, viable sperm is high.

Many patients freeze sperm for convenience and future availability, but for most patients there is a more specific reason to freeze the sperm. Often this is done prior to undergoing treatment for cancer. Sperm can be harvested through aspiration from the epididymis or testicle, and then preserved in quantities large enough to avoid having to have the surgery again in the future. For patients whose sperm numbers are low,sperm can be cryogenically stored to allow the couple to do inseminations or IVF. Additionally, any man who is anxious about producing a sample on the day of his partner’s insemination or egg retrieval can take advantage of this service.

It is of importance to note that not all cells survive freezing and thawing, but since most sperm samples contain millions of live spermatozoa, losing a small fraction of them has little consequence on the absolute number available for IVF, ICSI or other artificial insemination procedure. However, the drop in the number of live sperm should be expected. Despite only a handful of studies on the sperm cryopreservation, those that have been published are encouraging. Freezing and thawing does not cause any abnormalities, and freezing does not cause genetic abnormalities.