There are a number of reasons why a woman may choose to preserve their fertility. Even though egg freezing for social reasons is becoming more common internationally, one of the main main reasons is still due to illness such as cancer.
You can read more about the options below and in the 'Fertility Preservation' section of our Pathway to a child magazine here (PDF).
Egg Freezing and Storage
Since 2009 Fertility Associates has been able to able to offer egg freezing and thawing services to New Zealand women. Around 2000 babies have been born worldwide following the freezing, thawing and subsequent fertilising of eggs. Most have been born in the past few years, so this is a new technology with limited follow-up of the children. To date, Fertility Associates has had one baby born from frozen eggs.
Fertility clinics have been freezing cells for some time. The freezing of sperm has been available since the 1950s and the first frozen embryo baby was born in 1983. However eggs have proven much more difficult to freeze and thaw. The human egg is the largest cell in the body and freezing has frequently caused damage to the delicate spindle on which the chromosomes are lined up during the maturing process that is necessary before fertilisation can occur. New technology with improved freezing solutions has allowed eggs to survive the freezing, and recent work has shown the pregnancy rates from frozen eggs to be the same as when fresh eggs are used..Studies on the health of the children born following egg freezing have been reassuring thus far.
Egg freezing may be useful in a number of clinical scenarios, such as a woman who is about to undergo treatment for cancer that may cause her ovaries to fail, couples having IVF who have religious, moral or ethical objections to embryo freezing, where sperm is unable to be produced after the eggs have been collected in an IVF cycle or when a single woman wishes to store her eggs because her fertility is falling as she ages.
The process around egg freezing involves the same ovarian stimulation regime as those used in IVF. The eggs are collected, as for any egg pick-up (OPU), under sedating drugs and then frozen. When the woman wishes to use the eggs, they are thawed, the sperm is injected inside the eggs (ICSI) and the resulting embryos are placed in the woman’s uterus. If there are surplus embryos these are frozen.
Access to publicly funded fertility preservation for the retrieval, freezing and long term storage of gametes (specifically sperm and eggs) is available for people whose fertility will be permanently impaired by publicly funded treatment for medical conditions, such as by cancer treatment.
GPs and oncologists can contact their closest Fertility Associates clinic for details.
Ovarian Tissue Freezing and Storage
We can freeze and store small pieces of the ovary. There have now been 31 human pregnancies following the storage, thawing and replacement of ovarian tissue.
Transplantation of thawed ovarian tissue is still very experimental and has not yet been done in New Zealand. Transplantation cannot be done in New Zealand until the Ethics Committee on Assisted Reproductive Technology (ECART) has guidelines in place, and we understand there are no plans to create guidelines in the near future. The only way to use frozen ovarian tissue at present is to arrange for the transplantation to occur outside New Zealand.
Freezing of ovarian tissue is available to women aged 16 to 35 and who have a medical indication for this procedure, such as chemotherapy, radiotherapy or surgery, which has a significant chance of causing ovarian failure. The ovarian tissue is removed laparoscopically. Currently there is no public funding for the freezing and storage of ovarian tissue.
This technique may be used to help women at risk of losing ovarian function due to radiotherapy or chemotherapy as treatment for cancer.
Ovarian tissue freezing for fertility preservation is not publicly funded in New Zealand, and can only be offered as a privately funded treatment. Fertility Associates is working with the Child Cancer Foundation and the Ministry of Health to try and achieve publicly funded ovarian tissue freezing for cancer patients. Publicly funded IVF, embryo freezing and storage for cancer patients may be available under a clinical override process. GPs and oncologists can contact their closest Fertility Associates clinic for details.