Female fertility preservation - an overview
Female fertility preservation - an overview
Take-home messages
- There are many forms of fertility preservation
- The number of women choosing to freeze eggs due to nonmedical reasons is increasing
- There are pros and cons associated with embryo, egg and ovarian tissue preservation
Dr Melanie Davies, University College London Hospitals, London, UK
In this presentation, Dr Melanie Davies, University College London Hospitals, provided an update on fertility preservation in the UK. This article summarises key points from the presentation.
Who needs fertility preservation?
Women who are being treated for rheumatic diseases, malignancy or benign disease with cytotoxic agents and those undergoing pelvic surgery (eg for recurrent ovarian cysts) may benefit from fertility preservation. Women at risk of early menopause and those who have selected the procedure for personal reasons are also candidates.
What guidance is available on fertility preservation?
The British Fertility Society has published a guideline that brings together all the evidence on fertility preservation measures and outcomes:
Yasmin E, Balachandren N et al. Fertility preservation for medical reasons in girls and women: British fertility society policy and practice guideline. Human Fertility 2018;21:1
The Human Fertilisation and Embryology Authority website is a useful resource for both healthcare professionals and patients. It contains some useful statistics on fertility treatment in the UK: https://www.hfea.gov.uk/
The National Institute for Health and Care Excellence (NICE) has brought out a quality standard that covers assessing and treating fertility problems, including access to IVF treatment and cryopreservation before cancer treatment that may affect fertility: NICE quality standard 73: Fertility problems
Fertility Preservation UK is a British national non-profit organisation that aims to develop and promote best practice in the reproductive care of people with cancer and chronic disease.
Medical fertility preservation
The main reason for medical fertility preservation is cancer and its treatment.
With increasing cancer survival rates, there is a new emphasis on looking ahead to after treatment. The risk of amenorrhoea after cancer depends on the type of cancer and treatment.
Over 80% of cancer treatment is considered "high risk" in terms of amenorrhoea and this incudes bone marrow transplant conditioning, chemotherapy, total body irradiation and pelvic radiotherapy. However, most patients with cancer opting for fertility preservation tend to be "medium risk" or "low risk" for amenorrhoea as they have a better long-term prognosis.
Medium-risk patients include those with acute myeloid leukaemia, osteosarcoma, neuroblastoma, lymphoma and breast cancer. Low-risk patients include those with acute lymphoblastic leukaemia, brain tumours and Hodgkin's disease.
Types of fertility conservation
Modification of oncology treatment
Radical trachelectomy, in which most of the cervix and the upper part of the vagina are removed, but not the uterus, is one example of how oncology treatment may be modified. Fertility-sparing surgery for borderline cysts is another example.
Chemotherapy and radiotherapy regimens may also be modified to preserve fertility.
Embryo preservation
- Storing embryos is well established (it began in the 1980s and long-term outcome data are available)
- Frozen embryo success rate is the same as for fresh embryos
- Parents need to be together
- Both parents need to give consent for usage; if partners separate, it may be challenging
- It is important to use a drug such as letrozole to cap oestrogen levels in patients with hormone-dependent cancer
- Leads to a delay in cancer treatment of 2-3 weeks
- Post-pubertal patients only
Oocyte preservation
- Oocyte preservation is a relatively new technology
- Vitrification has transformed oocyte preservation and it is now established
- It can be used by single women and avoids ethical concerns about storing embryos if the patient does not survive treatment
- There is an equivalent success rate (pregnancy and live birth rate) with fresh versus frozen eggs
- It is important to use a drug such as letrozole to cap oestrogen levels in patients with hormone-dependent cancer
- Leads to a delay in cancer treatment of 2-3 weeks
- Post-pubertal patients only
Ovarian tissue freezing
- Much quicker (2-3 days) than freezing embryo or eggs (several weeks)
- It can be performed at any age including pre-pubertal patients
- It is limited in UK but more widespread elsewhere in Europe (especially Belgium, Germany and Denmark)
- Birth rate after regrafting is yet to be fully established
- If the patient has a bloodborne cancer, ovarian tissue regrafting may be unsuitable as cancerous cells may be present
Hormonal protection
- Gonadotropin-releasing hormone (GnRH) analogues may be used to suppress menstruation during chemotherapy
- It may have a possible fertility-sparing effect; however data are currently insufficient
- Currently, its main use is in lymphoma and breast cancer
- It is currently being used widely; however long-term outcomes have yet to be determined
Oophoropexy
- This involves elevating and fixing an ovary to the abdominal wall, allowing pelvic radiation treatment to occur without damaging the ovary
- According to Dr Davies, this technique could probably be used more often
Assessing a woman for fertility sparing treatment
When assessing a woman for fertility preservation, one needs to consider:
- the predicted effect of the cancer treatment
- the woman's prognosis
- the time available for fertility preservation
- the patient’s health
- the likely outcome for future birth (taking into account the patient’s age and ovarian reserve)
- it is essential to know about the patient's prognosis if they have cancer, before embarking upon cryopreservation
- it can be demanding and challenging ethically
A new online fertility decision aid, "Cancer, fertility and me" is being launched in August 2019.
Other points
- There has been a surge in women choosing to freeze eggs for non-medical reasons
- Apple and Facebook offer free egg freezing to their employees
- For an 80% chance of a live birth, a woman aged 38 needs to donate >20 eggs
- Women seeking to freeze their eggs are well advised to do so as soon as possible
Based on Davies M. Female fertility preservation – an overview. Presented on Wednesday 19 June 2019.
Top image: Cecilie_Arcurs
Article image: dem10
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