Corion Fertility Clinic


Cryopreservation is the procedure where Sperms, Oocytes & Embryos are preserved by cooling to low sub zero temperatures, such as -196 0C. At such low temperatures, all biological activities including biochemical reactions of gametes are effectively stopped.

Our Cryopreservation services include freezing of semen, Oocytes, Day 3 embryos as well as Day 5 Blastocysts.

Embryo Freezing

Conventional IVF treatment protocols often result in more than three eggs being collected during a cycle; resulting in excess embryos. Embryo Freezing provides couples the option of having excess embryos frozen, to be used in future cycles. There are many advantages of freezing embryos like reducing the risk of multiple pregnancies as we transfer fewer embryos in the fresh cycle and cryopreserve supernumerary embryos. We increase cumulative pregnancy rate by using cryopreserved embryos in thaw cycles. Cryopreservation cycles do not require ovarian stimulation and ovum pick up, the treatment is therefore significantly cheaper. Patients at risk of developing Ovarian Hyper Stimulation Syndrome (OHSS), can have the option of cryopreserving all embryos & prevent OHSS.

Two basic techniques have been developed:

1. Controlled slow-rate cooling protocol in which lesser concentration of cryoprotectant is used & cooling is performed at a very slow-rate. Using this protocol Cryopreservation of 2PN, Day 2 & Day 3 embryos can be done.

2. Ultra-rapid flash freezing protocol called Vitrification in which a very high concentration of cryoprotectants is used & embryos are plunged directly into the liquid nitrogen. Using this protocol Cryopreservation of 2PN, Day 2, Day 3 embryos as well as Cryopreservation of Blastocysts & Oocytes can be done.

Embryologists at Corion are used to both slow & rapid freezing methods. However, we are now only using Vitrification for our in-house freezing. You can read more about Vitrification at Vitrification and Frozen Embryo Transfer.

Semen Freezing

Semen Freezing is advised when the husband is not available at the time of infertility treatment [staying abroad or travelling].

As a back up when the husband is worried that he may not be able to produce a semen sample on the required day due to anxiety/stress.

Semen freezing is also recommended for men suffering from malignancies prior to their exposure to chemotherapy or radiation both of which may likely affect sperm production.

Details for Sperm Banking can be read at Semen Cryopreservation.

Oocyte Freezing

It offers women with cancer the chance to preserve their Oocytes prior to chemotherapy or radiotherapy.

Women undergoing treatment with assisted reproductive technologies, who do not consider embryo freezing an option, can rather freeze their oocytes for future use as a future ability to have children.

Women with a family history of early menopause have an interest in oocyte cryopreservation.

Now Corion is able to offer oocyte freezing for all such patients. Details for oocyte cryopreservation can be read at Oocyte Cryopreservation.