Oocyte freezing(Cryopreservation)

Oocyte cryopreservation (egg freezing) is a medical procedure to preserve a woman’s eggs at low temperatures so they can be used at a later date. Oocyte preservation enables women to postpone their pregnancy or save their eggs for later date as uterus remains functional in most advanced age women. Women undergoing cancer treatment also opt for oocyte freezing (Oncofertility)as some treatments of cancer can damage the eggs and can make such women infertile after completion of cancer treatment. The egg retrieval process for oocyte cryopreservation is the same as that for In-vitro fertilization (IVF). This includes one to several weeks of medication and gonadotrophin injections that stimulate the ovaries to grow eggs. Eggs (oocytes) are frozen using two methods. Either a controlled-rate, slow-cooling method or a newer flash-freezing process known as vitrification. Vitrification is much faster but requires higher concentrations of cryoprotectants to be added.  The breakthrough in achieving vitrification of a woman’s eggs has enhanced greatly practice of the IVF process, as the clinical pregnancy rate is four times higher after oocyte vitrification than after slow freezing.