What is the purpose of freezing spare embryos?

  1. Transfer of frozen thawed embryos from your previous IVF cycle gives you another chance at achieving a pregnancy without undergoing a full IVF cycle.
  2. Embryos from an IVF cycle where a transfer is medically not appropriate can be frozen so that the clinical problems can be rectified before embryos are transferred. For example:
    • Patients at risk of Severe Ovarian Hyperstimulation Syndrome
    • Inability to transfer embryos because of obstruction or another abnormality in the cervix (neck of the womb)
    • Patients undergoing this treatment prior to treatment for cancer so that they can store fertility

How is it done?

The embryos are transferred back to the womb after suitable preparation of the lining of the womb. As the embryos already exist, this cycle does not involve stimulation of your ovaries or an egg collection.

Freezing & Thaw of Embryos

Please note that you have to decide the fate of your spare embryos and that we act as per your written consents.

freezingEmbryo freezing:

  1. At the time of embryo transfer, we will discuss the fertilisation, growth rate and grade of embryos which is based on the embryo’s appearance. We will offer embryo freezing when deemed appropriate. Approximately 60% of embryos judged suitable for freezing survive and embryos with lower grades would have an even lower chance of survival. Before undertaking a frozen embryo transfer cycle, we try to ensure (as much as is possible) that upon thaw you would have at least some embryos suitable for transfer.
  2. Embryo freezing can only performed with your prior written consent. The legal storage limit for embryos is a maximum of 5 years from the date of freezing and this can be extended to 10 years if in the interim the female partner has reached the peri-menopausal years.
  3. The embryos are your property and responsibility. You also have to decide the fate of the embryos in the event of death or mental incapacitation. They deserve similar considerations as those for your unborn future child. Therefore we strongly advise you to always remain in touch with us, to advise us of your change in address, intentions and suggest that you consider replacement of your frozen embryos at the earliest possible opportunity.

Prolonged culture:

  1. With your written consent, thawed embryos can be maintained in culture until they stop growing or develop into the blastocysts (usually 2-3 days after thawing).
  2. Generally embryos with little chance of development to a pregnancy will stop growth within these days.
  3. Embryos that have showed growth after thaw generally have a higher developmental potential.
  4. After thaw and transfer, we are not legally permitted to keep embryos in culture for observation alone unless there is a clear instruction from you to preserve them when appropriate.

Embryo donation:

  1. You can consider donating your embryos to help another couple. This is very similar to egg and sperm donation, you would be required to have implication counselling and the necessary screening tests.
  2. We will advise you to consider this option for your frozen embryos after you have completed your family or decided to discontinue all future treatment for yourself.

Long term storage:

This section is primarily for the storage of embryos prior to chemo or radiotherapy for cancer. We will be pleased to provide specific information on the length of storage permitted legally in your case.

Posthumous use of gametes and embryos

Biologically only men can opt to permit their female partner to use their sperm or embryos created with them posthumously. There are ethical and legal concerns that you must consider very carefully before making a choice. We like you to have a discussion with the counsellor when considering implications of posthumous use of gametes to your future child.

Ethical issues:

In your considerations the ‘Rights and Welfare of your Future Child/Children’ must be paramount. These considerations must also precede and exceed your own wishes. The law clearly states that the child has a ‘right to have a father or a father figure for paternal nurturing’. It is our statutory obligation to ensure that this right is upheld. For instance, the law asks us to identify and counsel individuals who will have ‘parental responsibility’ and who will be ‘responsible for the paternal nurturing of your child’.

Legal issues:

The HFEAct provides that where a man’s sperm or embryos created with his sperm are used after his death, that he is not to be treated as the father of the child, except for the purpose of recording on the Register of Births as the Deceased father subject to the Human Fertilisation (Deceased Fathers) Act 2003 being fulfilled and for no other purpose. For instance, the child will have no entitlements to the man’s estate and if desired separate provisions will have to be made by the individuals concerned. The posthumous use of gametes or embryos is only possible if the sperm / embryos have been stored in the man’s lifetime and with his written consent. The unit will have a statutory duty to consider the Welfare of Future Children born posthumously and to assess what arrangements have been put in place to meet the future child’s needs when treatment is requested.

Humanely discard the spare embryos:

  1. Only good quality embryos can be successfully frozen, donated to another couple or used for research.
  2. If you do not wish prolonged culture with a view to freezing the embryos that continue growth, then you must instruct us to humanely discard your spare embryos as soon as embryo transfer has been performed.

Please see IVF consent forms for further details. We emphasise that these choices are entirely personal.

Embryo research

This is a HFEA licensed and very carefully regulated activity. All centres have to obtain specific research licenses for the projects that they may conduct or be a participant. This section intends to make you broadly aware of the issues that surround egg / sperm / embryo research and does not in any way constitute a request from us for you to participate. If the unit took part in Stem Cell research, you will receive more specific information about that project. In that case you will need to be aware that any stem cell lines created may continue indefinitely and that these lines may be later used in other relevant research projects.