Author: Hoi See Tsao
Institution: Wellesley College
Date: July 2007
At first glance, Carine appears to be an ordinary healthy nearly one-year-old infant. However, her normal development signifies a great success on the part of a group of Canadian researchers, as she is the first baby to be born from a fertilized, lab-matured egg.
The researchers' success with Carine provides an alternative for women who may otherwise resort to taking fertility drugs that are known to cause a rare but fatal condition called ovarian hyperstimulation syndrome. In addition, it brings hope for some cancer patients. As cancer-related fertility problems may be caused by chemotherapy, women with cancer may choose to freeze their eggs before they begin cancer treatment. However, even if the technique is shown to be successful with later births, depending on the cancer, not all women will be able to delay chemotherapy for ovarian stimulation. For example, some tumors, such as some breast cancers, accelerate their growth if a woman takes ovarian stimulation drugs.
The team, led by Dr. Hananel Holzer at the McGill Reproductive Cancer, Montreal, experimented on women with polycystic ovarian syndrome (PCOS). The ovaries of women with PCOS are covered with cysts, which may hinder fertility and which are linked with an increased incidence of ovarian hyperstimulation syndrome. Four out of twenty women successfully achieved pregnancy with the new technique, called in vitro maturation or IVM. In a fertility conference in Lyon, the researchers revealed that they were expecting the three other babies that were fertilized by the same process to be born soon. The team has not yet tried the technique on women with cancer.
"Until now, it was not known whether oocytes collected from unstimulated ovaries, matured in vitro and then vitrified, could survive thawing, be fertilized successfully and result in a viable pregnancy after embryo transfer," Holzer said in an interview with the BBC. "We have demonstrated for the first time that it is possible to do this and, so far, we have achieved four successful pregnancies, one of which has resulted in a live birth."
"Each step in this work had been achieved before, but this is the first time they have been successfully strung together," said Professor Robin Lovell-Badge, of the Medical Research Council's National Institute for Medical Research. "It is important as it will expand the choices available to women with diseases of the ovary or cancer and the clinicians treating them."
Nonetheless, Holzer warned that the data obtained was still in its early stages and that much more research is needed. Dr. Laurence Shaw, spokesman for the British Fertility Society, commented that, "These pregnancies are an exciting step. However, the pregnancy rate is very low and therefore large numbers of eggs would be needed." Shaw strongly emphasized that the in vitro maturation technique was only suitable for people suffering from fertility problems due to conditions such as PCOS or cancer and not for women who simply want to delay starting a family.
Written by Hoi See Tsao