Let’s shed some light on a topic that isn’t discussed enough - egg and embryo freezing. I’ve noticed that fertility treatment in general is kind of a black box, and so I wanted to get into the details of what exactly this process looks like, and discuss the potential pros and cons of each stage and various options.
Fertility naturally decreases as we age and can be affected by certain medical conditions requiring hormonal and chemotherapy. Egg & embryo freezing may be a good option for those looking to extend and preserve future fertility. This process involves stimulating egg maturation and release through injectable medications, an egg retrieval procedure, freezing, and eventual storage of eggs for later use. Embryo freezing is different in that fertilization with partner or donor sperm takes place prior to freezing. The embryos are observed for 5-7 days, at which point they may undergo genetic testing and are graded to determine which ones might be the most successful (1). The highest-graded embryos are then frozen and stored until eventual thawing and implantation.
This whole process is started off with a consultation and thorough medical assessment, usually with the physician at the chosen fertility clinic. Over a series of visits, patient background and medical history are discussed, necessary physical exams are performed, and diagnostic tests are ordered and interpreted. These tests include anti-mullerian Hormone (AMH), follicle-stimulating hormone (FSH), estradiol, and ultrasound of the ovaries to determine ovarian egg reserve quantity and quality. Infectious disease screening typically takes place as well through blood testing for infections like HIV, hepatitis, etc.
The next step in the process is the ovarian stimulation phase. During this phase a series of injectable medications are taken (at home) over 8-12 days, and regular monitoring (in office) through blood work and ultrasound every 2-3 days. Some of the medications used include daily FSH injections, which stimulate the ovaries to mature multiple eggs as opposed to a single egg during a typical menstrual cycle. A combination injection of FSH and luteinizing hormone (LH) is often used to stimulate egg production as well as promote ovulation. GnRH-antagonists are also given to prevent early ovulation so that the mature eggs aren’t released until just prior to egg retrieval. Leuprolide acetate or hCG is then taken on the last day, 36 hours before egg retrieval, to finalize maturation.
Egg retrieval is next in the process, it constitutes a relatively quick procedure performed under sedation. During this procedure an ultrasound probe is inserted into the vagina to view the follicles and a guided needle is inserted through the vaginal wall where a connected suction device collects the egg(s) (2). Cramping and feelings of pressure/bloating are not uncommon for a couple of weeks after this procedure, and complications are very rare (3). Nevertheless, antibiotics are usually recommended afterwards to limit the risk of infection.
Let’s backtrack a little here and briefly discuss the side effects related to egg stimulation and retrieval. Side effects from the hormonal medications are typically minor and are similar to PMS-like symptoms ranging from breast tenderness, bloating, headaches, mood fluctuations, insomnia, and hot flashes. Injection site irritation and bruising are also common. These side effects are short-lived, occurring only during the 10-day period (average) that the medications are taken. The retrieval is a minimally invasive surgical procedure that, as stated earlier, can result in infection but usually only results in a few days of period-like abdominal cramping. The most serious and rare side effect that can occur after stimulation is ovarian hyper-stimulation syndrome (OHSS), where the ovaries become swollen and painful. Severe cases occur in 0.1-2% of patients requiring close monitoring, bed rest, and potentially surgical intervention if ovarian torsion were to occur (4).
Freezing and storage of the eggs or embryos is fairly self-explanatory, but the process and associated costs can vary based on the chosen facility. Frozen embryo survival is slightly higher than frozen eggs due to their stronger, more structural multicellular makeup. Frozen embryo transfer used with IVF has its advantages including less procedures, medications, and stress before implantation, ease of planning with the use of already frozen younger embryos, and the benefits of genetic testing prior to implantation.
Here in Ontario, funding is provided to participating fertility clinics to cover costs for eligible patients. Eligibility is determined by residency status and having a valid OHIP card, not by sex, gender, sexual orientation or family status. Fertility preservation treatments are only covered if there is a medical reason disrupting fertility, and IVF is only covered one time (one cycle per patient, must be under 43 years old) and includes the one-at-a-time transfer of all viable embryos. Fertility drugs, genetic testing, and storage are not covered by government funding but may be included in some private insurance plans. Find out more about funded clinics and getting started at ontario.ca (5).
Author: Emily Howard, ND, BSc
References
1. Christianson M. Freezing embryos. Freezing Embryos | Johns Hopkins Medicine. https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/freezing-embryos. Published August 8, 2021. Accessed October 26, 2022.
2. Egg freezing. Mayo Clinic. https://www.mayoclinic.org/tests-procedures/egg-freezing/about/pac-20384556. Published April 23, 2021. Accessed October 26, 2022.
3. Your guide to egg freezing medication. Extend Fertility. https://extendfertility.com/egg-embryo-freezing-ivf-fertility-medication/#:~:text=Egg%20freezing%20patients%20are%20typically,follicles%20and%20to%20prompt%20ovulation. Published December 12, 2019. Accessed October 26, 2022.
4. Corbett S, Shmorgun D, Claman P, et al. The prevention of ovarian hyperstimulation syndrome. Journal of Obstetrics and Gynaecology Canada. https://www.jogc.com/article/S1701-2163(15)30417-5/fulltext. Published November 1, 2014. Accessed October 26, 2022.
5. Get fertility treatments. ontario.ca. https://www.ontario.ca/page/get-fertility-treatments. Published May 9, 2017. Accessed October 26, 2022.