Patients are often able to collect a large number of eggs which result in many viable embryos. Any remaining embryos that are not transferred into the woman’s uterus after a fresh IVF transfer may be frozen or “cryopreserved” in small tubes and kept and stored in the laboratory for future use.
Cryopreservation allows the patient to limit the number of embryos transferred “fresh” without discarding the unused embryos that could lead to a future pregnancy. The embryos can be kept in storage for many years.
Patients are often able to achieve several pregnancies from just one egg retrieval procedure. These frozen embryos can be transferred back with minimal preparation of the uterine lining. The correct transfer time is calculated based on the stage the embryo was frozen.
International Fertility Centre, Delhi has tremendous success with this procedure and currently has the highest success rate in the country for achieving pregnancy from frozen embryo transfer.
Successful cryofreezing of eggs, sperms and embryos has a track record of over 60 years. The first pregnancy in humans derived from frozen-thawed embryos was in 1983. With approximately one quarter of a million babies born following cryopreservation, this technology has become a widely used and well-established routine procedure for successful IVF.
The latest technique of freezing embryos is by vitrification rather than conventional slow freezing which has helped increase the success rates from a mere 25% to almost 55-60% with vitrified-thawed embryos. The International Fertility Centre, Delhi, under the guidance of its ace vitrification expert has taken this technology to a new peak consistently delivering results in the range of 50-60% with vitrififed thawed embryos in IVF and ICSI.
It is our endeavour now to vitrify some embryos for every patient who avails of IVF or ICSI at our centre.
At International Fertility Centre, Delhi, many of our births, over many years, have come from the transfer of frozen and thawed embryos. On average the success rate is about 30%, but this mainly depends on the age of the woman’s eggs when the embryos are frozen.
So, if you were to freeze your embryos in your first IVF cycle at the age of 38, and then use them when you’re 42, your fertility chance will be relative to that of a 38-year-old woman rather than a 42-year-old.