In vitro maturation (IVM) is the process of harvesting immature eggs and then maturing them in the laboratory. The potential advantage of IVM is that large doses of follicle stimulating hormone are not required as in traditional IVF where the desire is to collect a large number of mature eggs. Lower doses of hormone means a safer and less expensive procedure.
Researchers at McGill Reproductive Centre in Montreal, Canada claim to have successfully combined IVM with egg freezing. They collected immature eggs, matured them in the laboratory, then froze them for two months. After thawing they were fertilized and a successful pregnancy and birth resulted. The center claims this is the first time the combination of IVM and frozen eggs has been successfully demonstrated.
The details of the success are described in a story at
globeandmail.com. There is another interesting data point in that story, which is that in Korea, where natural cycle and IVM have long been pursued, doctors collect one mature egg that has ripened naturally and three to five immature ones that undergo IVM in the lab. They report success rates around 43% which is as good as standard IVF where large numbers of mature eggs are stimulated, collected and fertilized.
The story also says that about 1,000 babies have been born of IVM worldwide. That's the first time I've seen that statistic. The success rate of IVM is also stated as around 20 percent compared to standard IVF at 50 to 60 percent, according to the story. There is that 60 percent success rate number again. I still haven't seen any solid numbers from fertility centers that back up that claim. I've see a number in the 30 to 35 percent range - that is the probability of achieving a live birth from one round of IVF. Are they coming up with a success rate based on multiple rounds of IVF?
Labels: frozen eggs, IVM