When it comes to your fertility, preserving it isn’t quite as simple as locking it in a jar of vinegar to prevent it from expiring. Fertility preservation not only involves a lot more science but also, either freezing your eggs, embryos or reproductive tissue so that they can be used in the future to create your own biological children. Once collected, they are frozen and stored in liquid nitrogen – a process called cryopreservation. When you are ready to use them, they can be thawed and used to help you conceive. 

These processes are all designed to help those at risk of potential infertility, protect their chances of parenthood. This can be due to medical procedures, possible treatments or age-related decline that may could impact your fertility. 

Medical vs Social Fertility Preservation

Fertility preservation is usually categorised as medical preservation or social preservation. Medical fertility preservation is reserved for those who might lose their ability to reproduce due to impending medical treatment as in the case of chemotherapy or radiotherapy for cancer, hormone replacement therapy while undergoing gender reassignment surgery, those that have an autoimmune condition such as lupus or those at risk of premature infertility. Although some can get pregnant naturally after their treatment, these medical procedures have been found to diminish the ovarian reserve, making it difficult to conceive. This is why patients are recommended to consider fertility preservation before starting therapy. 

Social fertility preservation is when you freeze your eggs or embryos because of social and age-related influences, such as a demanding career or having not yet met that special someone. Fertility preservation offers the opportunity to put family life on hold, without relinquishing the prospect of procreation for good. It is important to remember that as you age, the number and quality of eggs in the ovaries decreases. Age is also related to an increased risk of birth defects. This is why women are recommended to consider fertility preservation if they are not ready for parenthood before their mid-30s. 

The UK currently has a storage limit of 55 years for samples that are cryopreserved for medical reasons. For social reasons, the storage limit is 10 years.

What are the options for fertility preservation?

Fertility-preservation options for women and AFABs include:

Egg freezing (Oocyte cryopreservation): 

Egg freezing is a popular choice for those who do not have a male partner, do not want to use a sperm donor or pursue embryo freezing. It can also be offered to those who are at an increased risk of early menopause.

The younger you are when you undergo egg freezing, the better the chances of retrieving more good quality eggs. 

The first step would be to have a baseline analysis of your ovarian reserve and bloodwork (we can do this for you). Once the baseline reports are analysed, your doctor will plan out a suitable medical plan. 

Your treatment will start with hormonal treatment to boost your egg production. This promotes lots of follicles to grow at the same time so that your doctor is able to collect as many eggs as possible. 

Your doctor will regularly monitor the growth of your follicles through ultrasound scans and once the follicles have developed to a desirable size, you will be given what is called a ‘trigger injection’, which will initiate maturation of the follicle. 36 hours after the trigger injection, your doctor will schedule a procedure called the oocyte retrieval, ovum pick-up or egg collection.

This procedure is done under mild sedation and usually takes under 30 minutes. The doctor will use a transvaginal ultrasound-guided needle to retrieve the eggs. During this procedure, an ultrasound probe is inserted into your vagina to identify follicles, and a needle is guided through the vagina and into the follicles. Fluid is removed from each follicle through the needle, which is connected to a suction device.

The eggs will be present in this fluid and will be analysed under the microscope in the embryology laboratory. Once the eggs are analysed they will then be frozen using a rapid method called vitrification and stored in tanks of liquid nitrogen.

When you are ready to conceive, the eggs will be thawed and fertilised with sperm. The resulting embryo will then be transferred to the uterus so that it can implant and result in a potential pregnancy.

The average time needed for an egg freezing cycle is 2-3 weeks. Sometimes if sufficient eggs are not collected in one cycle, your doctor could recommend another cycle depending on your personal situation. 

You can read more about egg freezing here.

Embryo cryopreservation (embryo freezing) :

If you are in a committed partnership, you can use your partner’s sperm. If you are single at the time you are choosing to undergo treatment, you could either opt for a known donor, who can be a friend or unrelated family member of your choice or opt for a donor from existing sperm donor databases.

Embryo cryopreservation would usually require an in-vitro fertilisation (IVF)  cycle. You can read more about IVF here

The first step would be to have a baseline analysis of your ovarian reserve and blood work as well as an analysis of the semen parameters. Once the baseline reports are analysed, your doctor will plan out a suitable medical plan for you. 

The next stages are similar to those undertaken during egg freezing. However, the only difference in the procedure is that embryo freezing starts with a stage of medication to suppress your natural hormone production before starting the medication to boost egg production.

Another difference is that only the mature eggs will be fertilised with the sperm once retrieved and analysed. They are then placed into an incubator to allow the resulting fertilised egg (embryo) to develop. 

The embryos are then frozen either by vitrification (fast freezing) and stored in tanks of liquid nitrogen. Once you are ready to conceive, the embryo will be thawed, cultured and will be transferred to the uterus. Here it can implant itself into the lining of your uterus and result in a potential pregnancy.

The average time needed for one cycle of IVF is between 4-6 weeks. However, for medical reasons, some women won’t have the first stage of treatment (suppressing hormone production), which brings their treatment time down to around 3 weeks. Sometimes, if a sufficient number of embryos are not collected in one cycle, your doctor will recommend another cycle.

You can read more about embryo freezing here.

Ovarian tissue cryopreservation:

Ovarian tissue cryopreservation is the only fertility preservation option to help younger patients who have not gone through puberty. It is also the choice for women who can’t undergo conventional IVF treatment because of oestrogen-sensitive cancers such as breast cancer.

The procedure is performed under general anaesthesia. A short key-hole operation (laparoscopic oophorectomy) is performed. During the operation, surgeons will check both ovaries and then remove one. The ovary is then transported to the laboratory and prepared for freezing. The tissue containing the immature eggs is cut into thin strips and carefully soaked in preservative fluid. This protects the tissue from any damage during the freezing process. The ovarian tissue is then stored safely in the ‘Tissue Bank’.

When you choose to use the tissue in the future, the ovarian tissue strips will be re-implanted to restore ovarian function and egg production.  

You can read more about ovarian tissue preservation services on the NHS here.

Ovarian transposition:

In this process, ovaries are surgically moved higher in the abdomen and away from the radiation field. This is to minimise exposure and potential damage prior to radiation treatment. 

Although it is very effective for those undergoing radiotherapy, it does not protect against potential damage caused by chemotherapy. 

Gonadal shielding:

Radiation treatment for cancer and other conditions can harm fertility, especially if it is used in the pelvic area. Some radiation treatments use modern techniques to aim the rays in a very small area. Depending on the location of the cancer, the pelvic area can be protected against radiation with a lead shield.

If you’re thinking about egg freezing or other forms of fertility preservation, Hertility can help. Our pathways to care consist of highly accredited and vetted clinics, that can guide you through your fertility journey, whichever path it is you choose to take.

References:

https://www.hfea.gov.uk/treatments/explore-all-treatments/
https://www.nichd.nih.gov/health/topics/infertility/conditioninfo/fertilitypreservation

Kim CH, Jeon GH. Fertility preservation in female cancer patients. ISRN Obstet Gynecol. 2012;2012:807302. doi:10.5402/2012/807302