Egg and sperm freezing

Freezing of sperm, eggs and embryos has been introduced to reproductive medical sciences at different stages. Successful sperm freezing was first carried in 1953, followed by successful embryo freezing thirty years later. These techniques have now become an integral part of assisted reproductive medicine. Hundreds of thousands of babies have been born worldwide as a result of treatment with frozen embryos and sperm.  

The world’s first pregnancy using frozen eggs was reported by Dr Christopher Chen in Australia in 1986. However; the development of the technique for egg freezing proved to be more complex than sperm or embryo freezing. A recent novel approach referred to as ultra-rapid freezing or ‘vitrification’ has proven to minimize drastically the risk of damage to the egg which was a frequent problem in the early years.  Now, >90% egg survival rate is seen in our clinic with success rates using our patients frozen samples being as good, if not slightly better in some cases, than using fresh samples. With the advent of ICSI (injecting sperm inside the egg) it is now possible to achieve similar fertilization rates with fresh and frozen eggs.

Egg freezing is an option for women with potentially curable cancer, as chemotherapy/radiotherapy has the potential to jeopardize fertility. In addition, the demand for egg freezing for nonmedical reasons often referred to as ‘social egg freezing’ is rapidly increasing. Women are born with a finite number of eggs and their fertility potential starts declining from the age of 35 years with a rapid drop from the age of 40 years.  Social egg freezing is an option for women of any age (usually in their thirties) who are keen to preserve their fertility until the time is right or they find the right partner. The National Statistics report published in January 2013 revealed that in 2011, nearly half (49%) of all live births were born to mothers aged 30 and over.

In the UK, the HFEA (Human Fertility and Reproductive Authority) records show that up to 2011 around 16,000 eggs have been stored in the UK for patients' own use and around 470 embryos from stored eggs have been created. The Centre for Reproductive and Genetic Health (CRGH) in London is one of the leading clinics in the UK with vast experience in egg freezing and the use of frozen eggs for IVF treatments. 

The egg freezing procedure involves administering injections to stimulate the ovaries for around 12 to 14 days. Following this, the eggs are collected under sedation. The egg collection is a relatively a non-invasive procedure, and carries a minimal risk of bleeding. The stimulation of the ovaries has been associated with a small risk of a complication referred to as ovarian hyper stimulation syndrome. However, we at the CRGH have developed a novel stimulation regime that does not trigger ovarian hyper stimulation which has drastically improved the safety of ovarian stimulation. The storage period for eggs is normally 10 years, however this period can be exceeded in certain circumstances.