Today “FREEZE ALL” & “FROZEN EMBRYO TRANSFER” is preferred over fresh transfer due to its much higher success rate.
The reasons are:
- The hormonal injections given to patient during super ovulation in fresh cycle produces very high level of hormone, Oestradiol which is actually harmful to endometrium & lower the receptivity of embryos so the success of fresh embryo transfer is lesser than FET.
- Technology of freezing has changed completely over the year. In the past, slow freezing was used which damages the blastomere of the embryos because of ice crystal formation. When the embryos were thawed survival rate of embryos was very low. Now a days, VITRIFICATION/ ULTRA- RAPID FREEZING technique is used in which there is no ice crystal formation & damage to blastomere is very low. Survival rate of embryos is more than 90%. At our center we are doing mostly freeze all & FET in which patient comes later according to their convenience. It is less stressful, more convenient with better pregnancy rate.