Female

Oocyte freezing & Embryo freezing

Why do I have to store eggs or embryos?

You are born with all the eggs you have for life. The number of eggs is getting smaller when you become older. Some cancer treatment can reduce and damage your eggs and affect your ability to have children.

You may be able to have your own children with the help of fertility treatment in the future if you freeze eggs or embryos before receiving cancer treatment.

Egg freezing

  • Suitable for women who are unmarried currently, or have religious or ethical objections to embryo freezing
  • Must be legally married when use the oocytes
  • The husband will not be able to use the frozen eggs if the patient passes away.

Embryo freezing

  • Mature eggs are removed from the ovary after stimulation with gonadotrophin and fertilized with your husband’s sperms and frozen for possible use in the future.
  • IVF and embryo freezing can only be performed for those who are legally married.
  • You won’t be able to use your embryos without your husband’s consent or if the relationship comes to end.
  • You or your husband will not be able to use the frozen embryos if one of you passes away.

Which method should I choose?

Egg freezing
Embryo freezing
Ovarian tissue freezing
Gonadotrophin releasing hormone agonists
Surgery to change the position of the ovaries

Egg freezing

  • Suitable for women who are unmarried currently, or have religious or ethical objections to embryo freezing
  • Must be legally married when use the oocytes
  • The husband will not be able to use the frozen eggs if the patient passes away.

Embryo freezing

  • Mature eggs are removed from the ovary after stimulation with gonadotrophin and fertilized with your husband’s sperms and frozen for possible use in the future.
  • IVF and embryo freezing can only be performed for those who are legally married.
  • You won’t be able to use your embryos without your husband’s consent or if the relationship comes to end.
  • You or your husband will not be able to use the frozen embryos if one of you passes away.

Ovarian tissue freezing

  • Suitable for young girls (may be their only option) or those who has to start cancer treatment very soon
  • Not suitable for cancers in which cancer cells may be present in ovarian tissue e.g. leukaemia or ovarian cancer
  • The whole ovary or the outer layer of the ovary will be removed, cut into small pieces and frozen.
  • The removal of the whole ovary or ovarian tissue can be done through laparoscopy or mini-laparotomy under general anaesthesia.
  • There are risks of anaesthesia and operation.
  • In the future, the frozen tissues is re-implanted into the body after cure of the cancer.

Gonadotrophin releasing hormone agonists

  • Suppresses the ovary using drugs (GnRH agonists) to protect from the effects of chemotherapy
  • Start 1-2 weeks before the first chemotherapy treatment and continue until cancer treatment is completed
  • Injection every 1-3 months (depending on preparation)
  • Side effects similar as menopause, such as hot flushes, mood changes, difficulty sleeping and vaginal dryness
  • Most evidence comes from patients with breast cancer. No sufficient evidence shows this method will definitely protect your ovaries. You may still develop early menopause and infertility despite using these drugs.

Surgery to change the position of the ovaries

  • Surgical procedure to move the ovaries out of the pelvis
  • Suitable for those receiving radiation therapy to the pelvis
  • Aim to lower the amount of radiation your ovaries are exposed to
  • Can be done by laparoscopy under general anaesthesia
  • There are risks of anaesthesia and operation

Comparing the different methods of fertility preservation

Oocyte freezing Embryo freezing Gonadotrophin releasing hormone agonists Ovarian tissue freezing
Time required 10-14 days 10-14 days 1-2 weeks before the first chemotherapy and continue until treatment is completed Within days if facilities are available
Price ~HKD $15,000-20,000 ~HKD $15,000-20,000 Several thousands N/A
Medical evidence Sufficient evidence
Mature technique		 Sufficient evidence
Mature technique		 Insufficient evidence Sufficient evidence
Immature technique
Flexibility Flexible Legally married Flexible Flexible

Not all women starting cancer treatment will need to consider these options. The decision of whether to pursue fertility is a personal one. You may refer to the flowchart for further information that may help your decision.

How are ovarian stimulation and egg collection done?

Pre-treatment evaluation
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Ovarian stimulation
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Egg collection
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Freezing of eggs or embryos

Pre-treatment evaluation

  • Pelvic ultrasound through vagina
  • Blood test

Ovarian stimulation

Hormonal injections each day for around 10-12 days to stimulate follicles in your ovaries to grow.

Egg collection

Eggs are collected using a needle passing through the vagina under transvaginal ultrasound guidance. The procedure is performed under sedation or anaesthesia. It takes around 10-15 minutes. Most women can be discharged on the same day. You will know how many eggs are collected immediately after the procedure.
Egg collection through vagina under ultrasound guidance

Freezing of eggs or embryos

Your eggs or embryos will be frozen and stored in liquid nitrogen.

IVF

Please refer to here.

What will happen at the fertility clinic?

You will meet our fertility specialist and be asked about your medical history.
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If you decide to freeze your eggs, you (and your parents if you are younger than 18 years old) will sign the consent.
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Transvaginal ultrasound scan will be arranged prior to the start of ovarian stimulation

How can I use the frozen eggs to make babies in the future?

Your husband and you can be referred to a fertility clinic when you have plans for babies. This is what will happen:

Be legally married before you undergo fertility treatment
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We will thaw your eggs, which will be fertilized with your husband’s sperms in the laboratory using a technique called intracytoplasmic sperm injection (ICSI) i.e. injection of a single sperm into each mature egg
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Embryo formed will be replaced to your womb. You may be required to take hormones to prepare your womb if you no longer have regular periods.
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You will become pregnant if it is successful.
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It is not advisable to conceive a baby too soon after completing cancer treatment because of the possibility of cancer recurrence and effects of chemotherapy on sperms and eggs. You should talk to your oncologist.

Embryo transfer


How long can I store my frozen eggs in the laboratory?

  • According to Code of Practice on Reproductive Technology & Embryo Research issued by the Council on Human Reproductive Technology in Hong Kong, you can freeze your eggs until you are 55 years old or for 10 years, whichever is later. You can specify an age limit lower than 55 or a maximum period of shorter than 10 years.
  • The contract needs to be renewed every two years.
  • The eggs will be discarded if you fail to renew the contract.

Can I terminate the storage contract?

Yes, you can inform the Centre anytime if you do not want to continue with the storage of frozen eggs.

How much does this service cost?

You have to pay for storage every two years.

How do I arrange the egg freezing service?

  • You can download a referral form from our website or obtain a referral letter to the Department of Obstetrics and Gynaecology, Queen Mary Hospital from your cancer doctor. Please fax the referral letter to 22554842.
  • We will arrange an appointment within one week.
Female Fertility Preservation Counseling Video