Tuesday, May 4, 2010


Cryopreservation is the procedure where sperms, oocytes or embryos are preserved by cooling to low sub zero temperatures, such as -196 degrees C. At such low temperatures, any biological activity including biochemical reactions of gametes are effectively stopped.

Our Cryopreservation services in Corion, include freezing of semen, Oocytes, Day 3 embryos as well as 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 Hyperstimulation 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 : http://www.corionfertilityclinic.com/frozen-embryo-transfer.php