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Egg, Embryo, and Sperm Freezing


Cryopreservation definition: preservation of cells by subjection to extremely low temperatures.

There are many different reasons that single individuals, as well as couples, decide to preserve their eggs, embryos, or sperm. Since fertility rates tend to decrease with age, some individuals/couples undergo this cryopreservation procedure to beat the biological clock of the human body.

Radiation and chemotherapy also have destructive effects on fertility, making it almost impossible for a person to conceive after the completion of their treatments. Before undergoing chemotherapy and/or radiation therapy, individuals often seek to undergo a cryopreservation procedure in order to increase the likelihood of having their own biological children. Egg, ovarian tissue, and sperm cryopreservation provides a significantly higher chance of conception for individuals/couples when they are ready to commit to having children and growing their family.

Happy couple expecting baby


Oocyte Cryopreservation definition: method used to save women’s ability to get pregnant in the future.

Oocyte Cryopreservation, the scientific name for freezing your eggs,  is the preservation of mature eggs following hormone stimulation to achieve pregnancy at a later time. This oocyte cryopreservation is currently offered to women who are interested in preserving their fertility or delaying a pregnancy electively. This procedure is also offered to women with a diagnosis of cancer who are at risk of losing their egg reserve and the potential to have a child due to surgery, chemotherapy, or radiation. Your egg reserve decreases significantly with the increasing reproductive age. Therefore, egg freezing is a smart option for women who want to have children later in life, but just can’t right now.

The process for egg preservation and freezing is quite simple actually.  

  • First, the patient will be given hormone treatments for 8-10 days.
  • Next, the patient will go through aspiration of the eggs under anesthesia next door to the Red Rock Fertility Center at Sunset Surgery Center.
  • Finally, eggs are frozen for fertility preservation purposes. 
  • *Eggs can be frozen for up to 12 years and will still be viable for implanting into the patient.

When the pregnancy is desired at a later time in life, eggs are then thawed and fertilized with sperm, and embryos are transferred into the uterus. This fertility process is called in vitro fertilization (IVF), a common type of treatment used for infertility patients.


Embryo Cryopreservation definition: process of freezing and storing embryos as a part of most IVF treatments.

The Embryo Cryopreservation process, also known as “embryo freezing,” involves storing embryos at a very low temperature so that they can be thawed and used at a later time.  An embryo consists of an egg and sperm that is already joined (or in other words, fertilized) and contains the genetic material from both the male and female parents.  Embryos are more stable than the fragile eggs, leaving them less prone to damage during the freezing and thawing fertility process.

Embryo freezing can take place 1-5 days after fertilization.  Typically, at Red Rock Fertility Center, we like to freeze the embryo during the blastocyst stage (day 5).  The reason for this is because most chromosomally abnormal embryos will stop developing in culture and do not progress to the blastocyst stage, leaving the strongest embryos which will lead to a better chance of pregnancy.


Sperm Cryopreservation definition: process of freezing sperm and storing it for future use.

Sperm freezing is offered to men for many different reasons.  Some may be undergoing testicular surgery, such as chemo or radiation therapy, and would like to preserve their future fertility. Age affects the quality of sperm, therefore, if you believe that it may be a while before you decide to actually have a family you may want to consider cryopreserving, also known as fertility freezing.

Frozen tissue can be viable and remain in good quality for up to 12 years. However, when stored properly, sperm cryopreservation can remain viable for many years. In fact, reported cases where sperm has been stored for 20 years before thawing and insemination has resulted in successful pregnancies. 

If you are considering a vasectomy, it is also a good idea to freeze your sperm, as we have seen many men come back 7 or 8 years later wishing to have another child. Vasectomy reversals are only about 60% successful, and even when successful, the sperm frequently is of lower quality. Lower quality sperm generally necessitates some type of assisted fertility technology, such as Intrauterine Insemination (IUI) or In Vitro fertilization (IVF). Having high quality frozen sperm generally yields better results than post-vasectomy sperm. Success rates using frozen-thawed sperm are comparable to fresh collected sperm in men with normal semen parameters undergoing IVF.

New mom holding her newborn baby


A detailed discussion with Dr. Eva Littman is recommended to advise on which freezing option is best for each individual.

To learn more about our cryopreservation procedures, or to schedule a consultation please fill out the form below or call (702) 749-4954 for more information.