Once the IVF/ ICSI treatments have generated the necessary number and quality of embryos for implantation, instead of conventional fresh embryo transfer, one can freeze the embryos by vitrification at appropriate stage of development and transfer them at a later date to improve the implantation rate of embryos.
Contrary to the old beliefs, frozen embryos survival rate after vitrification and thaw is over 90%. The success rates are also up to 20% higher in our experience, depending on patient age and circumstances. There is no evidence to show that this makes it more unsafe for embryos or babies born out of frozen embryos treatments, which is reassuring.
The reason why this approach works well may be because the uterus is more likely to accept embryos when the estrogen levels and progesterone levels are not high, there is no surgery and anaesthetics for egg collection procedure and possibly physically and mentally it is a much calmer situation for the patient.
We very much prefer this strategy as it achieves significantly higher live birth rates in our hands.