To date, it is possible freezing, sperm, embryos, oocytes, ovary tissues.
In routine, any centers freeze sperm and embryos.

Sperm cryopreservation :
It is the easiest and oldest technique : The straws contening about 0,250 ml of diluted sperm (in cyoprotectant mixture) are gradually frozen in liquid nitrogen vapor. After 40-60 minutes they are transferred into liquid nitrogen tanks for permanent frozen storage (-196°C.)
after 3 or 4 days, an initial "test sample" is thawed and tested again to ascertain from each specimen how well the sperm survived the freezing.

Indications :

Testicular Sperm Aspiration /Extraction :
MESA, microsurgical epididymal sperm aspiration :
This is an “open” procedure, performed under a general anaesthetic, where the scrotum is opened to expose the testis and its epididymis.
TESA, testicular sperm aspiration :
A fine needle is passed through the skin of the scrotum into the testes and suction is used to pull out some of the seminiferous tubules.
TESE, testicular sperm extraction
Including sperm freezing, if possible.
> After thawing an ICSI procedure can be used.

Procedures which could affect testis, prostate
Treatments for cancer ( (e.g. chemotherapy, radiation...)
Special medications (sulfasalazine, methotrexate...)
Vasectomy .....
> After thawing an IVF or ICSI procedure can be is used.

Embyo cryopreservation

Embryo cryopreservation is a current method used to preserve embryos by cooling and storing them at low temperatures. They can then be thawed at a future date and transferred to the uterus in a hormonally controlled cycle providing additional opportunity for achieving conception.

Freezing protocol
In first time, embryos are deshydrated and a Cryoprotectant takes place inside embryos. his cryoprotectant prevents ice formation inside and outside the embryo.
Then, Straws are filled by aspiration through an air permeable permeable plug inside the straw.

After freezing (about 2 hours) embryos are transferred into liquid nitrogen tanks for permanent frozen storage (-196°C.)

Example of Cooling Program (2 days embryo - Celsius degrees).

Vitrifying protocol
Vitrification is a more recently technique for rapidly cooling embryo.

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The Frozen Embryo Transfer Procedure - FET

The embryos are then steeped in 4 separate solutions to help remove any cryoprotectant used during the freezing process.
embryos are then warmed to 37°C in specfiic culture medium untill transfer.
The FET procedure is very similar to typical IVF embryo transfer procedures: the body will be monitored for ovulation and endometrial development and then the embryos will be implanted into your uterus.
A blood test is conducted 9 to11 days following transfer to determine if the patient is pregnant.

It is important to know that not all embryos will survive the freezing and thawing process though. About 80% of embryos survive cryopreservation. Only embryos with 50% or more normal blastomeres will be implanted