Embryo transfer
Previously, embryos that had been created through IVF were transferred back to the uterus on the 2nd or 3rd day, after collecting the eggs. Now, it is possible to let an embryo develop for 5 or 6 days, outside the uterus, reaching the blastocyst stage.
Advantages over early transfer:
1. Optimizing the result of pregnancy
2. Minimize the chances of multiple pregnancy:
By allowing a fetus to develop in the laboratory up to this stage, at 5-6 days, we are able to evaluate the quality of the fetus more accurately and provide more in-depth advice to couples on the suitability of embryos for freezing and The amount of embryos that will be better to transfer.
Women under the age of 40 by law cannot carry more than 2 fetuses and women over 40 more than 4.
Younger women with high-quality blastocysts suitable for transport can carry a single embryo as this will not negatively affect the result of pregnancy, it will minimize the chances of multiple pregnancy, while excess embryos will be able to be frozen.
3. Normal calculation of transfer time
During natural conception the eggs and sperm are fertilized in the fallopian tubes, where they continue to divide and reach the uterus only on the fifth day after fertilization at the blastocyst stage. Therefore a transfer on the fifth day reflects this normal growth time.
4. Confirmation of the quality of the embryo before freezing:
In couples with a good prognosis of freezing supernumerary embryos at this stage as embryos that do not reach the blastocyst stage up to day 5-6 will not be able to lead to a successful pregnancy. Similarly, we recommend freezing high-quality blastocysts to ensure a high chance of survival from the freezing/thaw process. (>90%).
Ioannis A. Sklavounos MD MSC DFFP
Obstetrician Surgeon Gynecologist
Specialists & Retrained in Great Britain
T.Senior Clinical Fellow – Liverpool Woman’s Hospital UK
IVF
