Fertility Preservation for Women and Men
Storing biological reproductive imprints for the future has been occupying humanity for some time. Storing animal gametes particularly sperm for animal husbandry has been successful for decades. Translating the technology to humans took a while to develop and improve. Freezing men’s sperm (in liquid nitrogen at -196o C) began in the 1960s while embryo freezing following IVF begun in the mid 1980s. Egg freezing was attempted at the same time as embryo freezing, but took longer to develop, and only now in 21st century has it become clinically accessible to women with the development of vitrification, a new freezing technique.
Biologically, women (and maybe men) have the best opportunity to conceive and have a healthy child when they are in there 20s and early 30s. This is when eggs have the highest probability of being chromosomally normal, and when fertilised to create a normal embryo.
The purpose of fertility preservation is primarily to improve quality of life. Counselling and careful reading of the many consents forms, is helpful and best done early in the decision making process.
Who benefits from gamete freezing?
1. Young Women and Men, who have not completed their fertility needs, recently diagnosed with cancer. This is now extended to medical therapies that incorporate chemotherapy that may cause ovarian loss of function, for benign noncancerous conditions.
2. Social freezing of embryos, eggs or sperm is a process which assists men and women planning when to start a family. Modern way of life for some professionals demands a financial and secure family life as a priority before starting a family. Storing embryos, eggs and sperm may provide this security.
3. Women may face medical conditions as severe endometriosis, lupus, pre cancerous ovarian cysts, surgery that involves removal of large proportion of ovaries.
4. Men who are contemplating vasectomy or having surgery on their testicles.
New Medical and surgical treatments that have been introduced to cure and maintain health and improve the quality of life, but a side effect of these therapies is a profound decline in fertility potential.
When is best time to freeze sperm?
This is not greatly impacted on by age of the man. Ejaculated or surgically aspirated sperm and testicular tissue can be stored for later use.
When is the best time to freeze embryos and eggs?
In general it is considered best to freeze embryos and eggs when a women is less than 40 years old. The younger the woman the more efficient the preservation process is. Factors that influence the timing other than age is ovarian reserve as measured by hormone tests and ultrasound examination of the ovaries.
For women faced with medical therapy that will impact her fertility and the opportunity to have or complete her family, it is best to consider the option of freezing eggs or embryos before her treatment. It is best to offer women individual advice, based on several factors including age, ovarian reserve, medical condition, planned therapy and operation and should include the possibility of natural conception.
The procedures for egg freezing follow those for standard IVF. These include preliminary tests to exclude communicable infections (HIV, Hepatitis B and C screen), a trans vaginal ultrasound scan and blood hormone test for ovarian reserve. This is followed by a schedule of medications to stimulate multiple eggs retrieval. The procedure of egg retrieval is carried using trans vaginal ultrasound guided technique under intravenous sedation (a mild general anaesthesia). Mature eggs are identified by the scientist in the embryology laboratory and frozen on same day they are retrieved.
Eggs are generally frozen (cryopreserved) for 5-10 years but this can be shorter or longer based on individuals choice and medical advice. It is generally preferred from a medical point that women plan to have a family before the age of 50.
Read more about fertility preservation.