IVF fertilization with frozen eggs is difficult to succeed

In vitro fertilization will have less chance of success if a frozen egg is used, researchers say.

Dr. Kutluk Oktay
(Photo: physiciansweekly)

In vitro fertilization, the egg is fertilized by sperm outside the body, and the embryo will be implanted into the mother's uterus. The eggs may be "fresh" or have been refrigerated over time. People often resort to cryopreservation techniques for women with certain types of cancer or other diseases, and the ovaries need to be preserved before performing toxic treatments for the body.

Nearly two decades have passed since the first frozen eggs were used for IVF, but the effectiveness of this method compared to the use of fresh eggs is still unknown, Dr. Kutluk Oktay and plus from School of Medicine Weill, Cornell University, New York.

The scientific team conducted an analysis of data from 26 studies published between January 1997 and June 2005, investigating the results of in vitro fertilization with cryopreserved eggs. These data are then compared with the results of the research team using fresh eggs in 2002-2003.

The results showed that the probability of a sperm-injected egg being a survivor is 6.6% if it is a fresh egg. While this rate seems to be lower with frozen eggs - only 3.4%.

For each successfully transplanted embryo, the survival rate was 21% and 60%, respectively, with the use of frozen eggs and fresh eggs.

Frozen egg in vitro fertilization "appears to be a salvage solution to preserve fertility" in women who will undergo radiotherapy or chemotherapy - techniques that can destroy fertility eggs - the authors conclude. However, "its value for non-urgent applications needs to be reviewed".

T. An