Baby boy is first successful birth in Canada from frozen eggs

May 31 2005

McGill University Health Center (MUHC) in Montreal yesterday announced the first successful birth in Canada resulting from frozen eggs. A healthy baby boy, weighing 3740 grams was born on April 29 to a 26-year-old mother who had suffered from infertility for two years.

Professor Seang Lin Tan, Chair of the Department of Obstetrics and Gynecology at McGill University and Director of the McGill Reproductive Centre at the MUHC in Montreal, who led the team says they are the first in-vitro fertilization (IVF) Centre in Canada to achieve this success, which is fantastic news for both the family and for fertility health research.

The mother, a patient of the McGill Reproductive Centre, had initially planned to undergo treatment with ovarian stimulation and intra-uterine insemination (IUI), but because she produced too many follicles in her ovaries, the treatment cycle had to be cancelled because of a high risk of multiple-fetal pregnancy. As an alternative treatment, eggs were collected from her ovaries, and then frozen in liquid nitrogen at -196ºC. After a period of two months, the eggs were thawed and fertilized with her partner's sperm through in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), and the resulting embryos implanted in her uterus.

Dr. William Buckett, the MUHC physician who looked after the mother during the pregnancy, says the mother had an uncomplicated full-term pregnancy and straightforward delivery. The parents, who remain anonymous, described the procedure as easy and uncomplicated.

McGill Reproductive Centre are pioneers in a revolutionary new rapid freezing technique called vitrification, which has dramatically increased egg survival rate. Because human eggs are very fragile and have high water content conventional methods of freezing have been relatively unsuccessful because they allow the formation of ice crystals, which damages the cells and makes the egg unusable.

The technique was developed at McGill by Dr. Ri-Cheng Chian, Scientific Director of the McGill Reproductive Centre and Dr. Tan. Each egg extracted from the ovaries of the patient is drawn into a protective device, called a "Cryoleaf", and then placed in a special vitrification solution. The eggs undergo super-rapid cooling at a rate of more than 20,000ºC per minute, which prevents ice crystal formation and increases egg survival to approximately 90%. The frozen eggs can then be safely stored in the Cryoleaf until it is ready for use, at which point it is carefully thawed, then fertilized.

So far 15 patients at the McGill Reproductive Centre have had embryo transfer produced from vitrified eggs, resulting in 7 pregnancies including this livebirth.

Dr. Tan says that the results are particularly encouraging because the success rate is comparable to regular IVF cycles with ICSI using fresh eggs in many IVF centres.

Dr. Lucy Gilbert, Director of Gynecological Oncology at the MUHC says that egg freezing is useful for a number of reasons.Gilbert says the process enables young women diagnosed with cancer to preserve their fertility before undergoing chemotherapy and radiotherapy, which can cause infertility and premature menopause. During the last two years, 16 cancer patients have had their eggs frozen at the MUHC.

Dr. Tan also points out that egg freezing also allows young women who wish to delay childbearing to do so safely. After 30 years of age, a woman's fertility declines and the rate of spontaneous abortion increases significantly. The risks of chromosomal abnormalities, such as Down's syndrome, are also higher in babies produced by older women. Finally, current egg donor programs require matching the menstrual cycle of egg recipients; this problem can be eliminated with egg freezing.