Preserving one’s fertility involves freezing your eggs and sperm in straws or any other method of cryopreservation, and storing them in liquid nitrogen for a certain time period.
By doing this, you can keep your reproductive cells intact for an indefinite period of time until the moment when you wish to have offspring by means of Assisted Reproductive Technology (ART).
Freezing ovarian or testicular tissue is another option, although both are still experimental procedures. Preserving reproductive tissue might be the option of choice in those cases where freezing eggs or sperm is not possible.
The various sections of this article are assembled in the following table of contents.
When to consider preserving your fertility
Basically, there exist two patient profiles when it comes to considering preserving one’s fertility: firstly, for medical indication in the case of cancer patients, and secondly for non-medical reasons, as in the case of the age-related fertility decline that occurs in women who decide to postpone motherhood.
Cancer patients can see their fertility damaged after undergoing chemotherapy and/or radiotherapy. Both stand for very aggressive treatments that attack the cells that produce eggs and sperm, which causes them to become infertile. In such cases, gamete cryopreservation could prevent them from having to end up using donor eggs or donor sperm in the future.
According to the ASRM (American Society for Reproductive Medicine), information on fertility cryopreservation programs should be offered to oncological patients as soon as they are diagnosed with cancer:
When damage to reproductive organs due to cancer treatment is unavoidable, cancer specialists should inform patients of options for storing gametes, embryos, or gonadal tissue and refer them to fertility specialists who can provide or counsel them about those services.
Also, when a woman decides to delay motherhood for social reasons and become a mother at an advanced maternal age, egg freezing may be the best option. Women are born with a limited egg supply that diminishes as they age. From puberty onwards, this ovarian reserve continues to decrease monthly with each menstrual cycle until its complete depletion, a period known as menopause.
Fertility preservation methods
In order for one’s fertility to be preserved, it is necessary to use a widely known technique in the field of ART: vitrification. This method of cryopreservation involves the ultra-rapid freezing of specimens in liquid nitrogen.
Progress made in this field has enabled us to:
- Freeze eggs
- Freeze ovarian tissue (experimental)
- Freeze sperm
- Freeze testicular tissue (experimental)
- Freeze embryos
To this purpose, it is necessary to use cryoprotectants. These molecules help prevent freezing damage to cells and tissues due to the formation of ice.
Egg freezing or egg vitrification is a method that consists in cryopreserving egg cells in vitrification straws using cryoprotectants. Ova are stored in tanks filled with liquid nitrogen called egg banks. This allows for the oocytes to be stored for an unlimited period of time without losing their physical and functional properties.
To freeze egg cells, women have to self-administer a series of hormonal medications that cause their ovaries to produce multiple eggs at the same time. Once mature, they are aspirated directly from the ovary by means of ovum pick-up (OPU), a surgical intervention that is done under sedation.
The main advantage of the vitrification method is that it allows us to achieve high post-thawing oocyte survival and recovery rates.
Contrary to women, in the case of males there is no need to take hormonal medications prior to freezing and storing their sperm cells. The only thing men have to do is collecting a semen sample after a 3-to-5-day period of sexual abstinence. Sperm quality will be assessed in the laboratory (concentration, motility, morphology, and vitality) by means of a semen analysis (SA).
Finally, the sample will be processed to obtain only high-quality sperm and package them in straws, which will be sealed and stored in a sperm bank. Frozen sperm samples can be stored until the man decides to father children.
Ovarian and testicular tissue freezing
Firstly, it should be clear that freezing a complete ovary or testis is not possible. However, one can choose to freeze a small portion of reproductive tissue retrieved from any of them. In women, this method is known as ovarian tissue freezing and, in the case of men, testicular tissue freezing.
Both methods are indicated in cancer patients, mainly in the following cases:
- Childhood cancer: since puberty has not been hit yet, and therefore no production of gametes occurs, freezing eggs and sperms is not possible in children with cancer.
- Women with cancer requiring immediate treatment: there would be no time to follow an ovarian stimulation cycle to collect and freeze egg cells.
- Women with hormone-dependent cancer: medications to induce ovulation, a step necessary for egg freezing, are contraindicated.
According to the ASRM guidelines, fertility preservation in young cancer patients should be an option only if the child agrees:
Parents may act to preserve fertility of cancer patients who are minors if the child assents and the intervention is likely to provide net benefits to the child.
The procedure involves the removal, by means of biopsy, of small parts of cortical tissue from the ovaries of the woman or the seminiferous tubules of the man. Both organs are responsible for the development of egg and sperm cells during adulthood. In children, these tissues contain egg- and sperm-making stem cells.
After being biopsied, immature tissue is dissected and cut into fine slices that will be stored in liquid nitrogen. Then, after confirming that the patient has overcome cancer, and after having reached adulthood, reproductive tissue will be auto-transplanted in the ovary or the testis. Transplantation can be done in another body part, such as an arm.
It requires complex surgery and success rates are slightly lower than those of egg and sperm freezing due to the technical complexity of the process and the limited survival rate of transplanted tissue.
An alternative option to egg vitrification available for heterosexual couples is freezing fertilized eggs as soon as they start to divide. Couples may prefer to choose embryo vitrification over egg vitrification because it offers higher post-thawing survival rates.
The process for cryopreserving embryos is similar to that of egg vitrification. The embryos are placed in a medium with a concentration of cryoprotectants, and then packaged in vitrification straws. Then, the straws are stored in an embryo bank, where they will remain in liquid nitrogen until the couple wishes to use them.
Ovarian function suppression (OFS)
Although this is still an experimental method, suppressing ovaries with medicine is another option for preserving female fertility. It is mainly indicated in women with breast cancer. Studies suggest that women undergoing chemotherapy who are treated with a luteinizing hormone-releasing hormone agonist are more likely to get pregnant in the future.
Luteinizing hormone-releasing hormone agonists are medicines that lower the quantity of sex hormones in the body, thereby stopping the production of estrogen and progesterone. They are also called LHRHa, LH-RH agonists, gonadotropin-releasing hormone agonists, or GnRH agonists.
The list of LH-RH agonists that can be used for OFS includes Lupron (leuprolide), Trelstar (triptorelin), and Zoladex (goserelin). Clinical trials indicate that temporary suppression of ovarian function with LH-RH agonists may help reduce the risk of premature ovarian failure (POF) caused by chemotherapy.
The cost of preserving your fertility varies depending on the treatment and the complexity of the procedure. The simplest and, subsequently, the cheapest technique is sperm freezing, which cost can range from $1,000 to $1,200 plus an annual storage fee of $250-$450.
On the other hand, egg and embryo freezing are more complex and laborious methods, which translates into higher prices. Embryo freezing costs $12,400 per cycle of IVF on average, plus an additional $400–$600 fee per year for storage. As regards egg freezing, the overall cost is $11,900 per cycle, plus $300–$500 annually.
As for ovarian tissue freezing, the cost is approximately $10,000 for surgery, plus $300-$500 per year for storage. However, this price is an estimation, as it may be reduced due to the experimental nature of the procedure. The same applies in the case of ovarian suppression, which success rates are still unknown, and the costs per month are roughly $500.
FAQs from users
Is there an age limit on egg freezing?
In principle, there is no age limit on egg freezing; a woman can decide to do it whenever she wants. However, one should consider preserving her fertility at a young age, as egg quality is better at this point. This, at the same time, translates into higher chances of getting pregnant in the future by means of IVF.
How can you keep sperm alive outside the body?
The only possible way to do this is by means of sperm banking. Today’s freezing methods allow us to store sperm and reach almost the same success rates as if it has not been frozen previously. Thanks to the cryoprotectants and ultra-rapid freezing methods used, sperm can be kept alive outside the body, without being damaged and with almost the same fertilization potential.
Can you freeze sperm and egg cells at home?
Reproductive cells cannot be stored at home. For egg and sperm cells to be available for later use, they have to be cryopreserved at special conditions. Moreover, in the case of egg freezing, surgery is necessary prior to storing the ova, so the woman has to necessarily visit an egg bank or fertility clinic.
How long does sperm last frozen?
Sperm can remain frozen indefinitely. The method used for sperm banking allows us to store the samples without causing any damage to them, and keeping their physical and functional properties almost intact.
Suggested for you
Would you like to learn more about freezing and vitrification methods for storing gametes and embryos? You can read more about them in the following article: Gamete and embryo freezing, how does it work?
On the other hand, we have talked about male fertility preservation options from a general point of view. If you are interested in the different methods available for men to save and protect their fertility, do not miss this post: Options to preserve fertility in men with cancer.