Egg Sharing/ Donation is the process by which a woman donates eggs to enable another woman who previously thought that they could never have children because of premature ovarian failure or menopause to conceive as part of an assisted reproduction treatment.
Criteria for Egg Sharing/Donation
In order to become an egg-share/ donor women are required to:
- be under 36 years of age on the day of egg collection
- be within a healthy weight range, with a Body Mass Index (BMI) of ideally less than 30 and no more than 35
- be a non-smoker
- have no personal or family inherited illness disability
- have normal levels of Follicle Stimulating Hormone (FSH), as assessed by blood test and reasonable number antral follicles at diagnostic scan (>/= 10).
- screen negative for Sexually Transmitted Infections (STIs) and genetic diseases
Benefits of Egg Sharing
- It helps families be able to have their own child.
- It allows older women to still become mothers.
Side Effects of Egg Sharing
- Complications like abdominal pain, swollen ovaries, blood clotting, bleeding issues, and infection after the egg retrieval process is completed are possible with this procedure.
- The fertility drugs involved can cause a pregnancy of multiples.
- Over-stimulation of the ovaries can become permanent.
- Many women do not know who receives their eggs.
- It may still lead to eggs that have genetic defects.
Embryo of very good quality can be frozen if agreed in advance by the couple. These frozen embryos can be used within a period of 2-3 years at anytime to extend the family.
Indications for Embryo Freezing
- Supernumerary embryos left after transfer of selected embryos in a fresh cycle.
- Avoiding fresh embryo transfer in stimulated cycles in patients at risk of OHSS, elevated progesterone, thin endometrium, fluid in the endometrial cavity on day of transfer, polyps detected incidentally following stimulation, bleeding and difficult embryo transfers.
- Blastocyst cryopreservation following trophoectoderm biopsy for PGS/PGD.
Process of Embryo Freezing
Embryos can be frozen from Day 2 (4- cell stage) to Day 5 (Blastocyst). They are loaded on thin plastic cryodevice, sealed at both ends. Each cryodevice is labelled with unique patient ID, date and number of embryos loaded. In the end all cryodevices are transferred to the storage tank filled with liquid nitrogen (LN2).
Advantages of Embryo Freezing
The main benefit of embryo freezing is the option to have frozen embryos thawed and transferred to the woman’s uterus in the future without having to undergo stimulation of the ovaries or egg retrieval. It is also possible that there may be enough frozen embryos for more than one subsequent cycle. Also, Frozen Embryo Transfers (FETs) are less stressful than fresh cycles because they don’t have to worry about egg production or if there will be viable embryos, since those procedures have already been done.
Disadvantages of Embryo Freezing
Approximately 70% of the embryos that are frozen will survive the thawing process. This does however vary between patients and it is possible that none of a couple’s embryos will survive the freezing and thawing process.
Success Rates with Frozen Embryos
The pregnancy success rate of frozen embryos is equal to the pregnancy success rate for fresh embryos. However individual factors can affect every patient’s prospect of success.