What is cryopreservation?
Cryopreservation involves freezing and thawing of the cells, without affecting its viability. It is a well-established procedure in the IVF centres. This procedure involves placing the cells indefinitely in an inactive frozen state in liquid nitrogen at -196ºC. Upon requirement the cells are thawed and used for treatment.
Why freeze sperm/semen?
Semen cryopreservation is a simple procedure and it is done by rapid freezing and thawing method. Semen freezing is done in the following cases:
⦁ As a back-up- If the husband is away or could not be able to produce the sample due to stress, anxiety
⦁ Prior to Vasectomy procedure
⦁ Prior to chemotherapy or radiation therapy
⦁ Low sperm count or deteriorating sperm quality
⦁ As fertility preservation as in case of high risk jobs like military, exposure to radiation, extreme temperatures
⦁ Sperm donation
Why freeze eggs?
The active phase of fertility of a woman is till early thirties and as the age advances the quality of the egg diminishes. This egg freezing procedure allows a woman to preserve her fertility by freezing and storing her own eggs and use it in future whenever she is ready to start a family. Potential candidates for Egg freezing procedure are:
⦁ Fertility Preservation: This is the best option to preserve one’s fertility by extending their biological clock.
⦁ Premature Ovarian Failure
⦁ Prior to cancer treatment – Chemotherapy or radiation therapy (these treatment can lead to destruction of ovaries and its ability to produce healthy eggs).
⦁ In conditions like endometriosis or ovarian tumours (this may cause scarring or compromise ovarian health).
⦁ Egg donation.
Why freeze embryos?
IVF treatment involves stimulated cycles, to produce many eggs which may result in many embryos. In order to avoid the risk of multiple pregnancies, only few embryos are transferred (D3 – two to three embryos; D5 – one to two blastocyst) and the rest surplus embryos can be stored. Embryos are usually frozen in the following situations:
⦁ Ovarian hyperstimulation syndrome (OHSS) – where transferring of embryos can be life threatening for the patient.
⦁ To reduce the risk of multiple pregnancies.
⦁ In case of surplus embryos (can help to increase the cumulative pregnancy rate).
⦁ Fertility preservation – social or medical reasons.
⦁ Embryo donation.
What is the longevity of storage period?
The gametes or embryos, once frozen in liquid nitrogen can remain unaffected for many years. But according to Indian guidelines (ICMR guidelines), the gametes or embryos can be stored upto 5 years.