Cryopreservation of embryos is a process of freezing live embryos at subzero temperatures. The process is quite fascinating and merits further insights.

Cryopreservation is done on day 1-3 embryos which are in dividing or cleavage stage. It can also be done on day 5 embryos in blastocyst stage. These frozen embryos can be reused for future embryo transfers with success rates comparable with fresh embryo transfers.

HOW IS IT DONE

Embryos made by in-vitro fertilization or intra-cytoplasmic sperm injection process (IVF/ICSI) are assessed for their quality on day 3 or day 5. As the process of cryopreservation is stressful for embryos, only good quality embryos are chosen for cryopreservation.

Cryopreservation is achieved by sequentially incubating the embryos in increasing concentrations of cryoprotectants. The cryoprotectant draws water out of the embryo and itself enters the cell by osmosis. This step is very crucial to prevent rupture of embryos during freezing. In the final stage, which is measured in seconds, the embryo is placed in highly concentrated cryoprotectant solution and is quickly loaded into a straw. The straw is then sealed and plunged immediately into liquid nitrogen. The whole process is called vitrification which has replaced older slow freezing method of cryopreservation of embryos.

Once frozen, embryos can be stored and reused for as long as 10-12 years. Liquid nitrogen cryocans containing embryos are monitored on day to day basis for optimal storage conditions.

ADVANTAGES/APPLICATIONS

• Preservation of surplus/spare embryos obtained in IVF cycle after fresh embryo transfer for subsequent use.
• Cryopreservation prevents ovarian hyperstimulation syndrome (OHSS) which may occur in case of hyperstimulation or fresh embryo transfers.
• Cryopreservation of embryos give sufficient time to treat any associated factors of infertility like fibroid/endometriosis, poor endometrial lining, hormone imbalance so that embryos can be transferred at later stage.
•  Increased pregnancy chances as frozen embryo transfer cycles have better hormonal control.
•  Possible increased chance of attainment of pregnancy in a single IVF cycle through multiple embryo transfers.
•  Reduction in risk of multiple pregnancy by cryopreservation of excess of embryos exceeding optimal number of transfer.
• Fertility Preservation measure for women who have male partners.
• Cryopreservation of embryos permits couples who have conceived to donate their surplus embryos to childless couple or for research purposes.
• In case of donor oocyte programs, embryos can be frozen so that there is no need to synchronize the menstrual cycle of donor and recipient.
•  Cryopreservation allows couples in whom the female partner can’t carry the pregnancy on their own due to medical conditions to have their own biological child through surrogacy.
• Cryopreservation permits pre-implantation genetic diagnosis so that genetically normal embryos can be transferred.

Cryopreservation is a highly sophisticated technique in the field of ART which requires excellent laboratory facilities with skilled embryologist. Ruby hall clinic IVF department, under eminent Dr.Sunita Tandulwadkar and her team of expert embryologists have been carrying out cryopreservation of embryos over 15 years with excellent results. Ruby hall clinic is Pune’s first nationally accredited hospital with a dedicated centre for infertility and endoscopy. Specialized procedures like cryopreservation of embryos are carried out by highly qualified embryologists with updated, international standard, state-of-the-art instruments. Through her years of experience, rich knowledge and skills in the field of infertility, Dr.Tandulwadkar has been ray of light for many childless couples who have realized their dreams of having a child.