After egg retrieval, embryologists collect the eggs from the follicular fluid which was aspirated from the ovaries. Eggs are counted, washed and transferred to Petri dishes with a special nourishing medium. The Petri dishes are placed in an incubator where egg maturation continues.
Embryollogists confirm the number of collected eggs and select the ones that are fit for fertilization, transfer them into Petri dishes containing a special nourishing medium, and place them inside ihncubators where their maturation continues.
In some patients, very low fertilization rates or no fertilization are observed in a previous ICSI procedure. In these cases, oocytes can be incubated in a special medium containing calcium ionophores. Oocyte calcium deficiency is one of the possible causes of failed oocyte activation after intracytoplasmic sperm injection.
Cryopreservation is used to maintain the viability of cells over long periods. It is achieved by freezing and liquid nitrogen storage at ultralow temperatures – 196°C. At Nadezhda hospital, we employ vitrification, the most modern and effective cryopreservation technique. Vitrification is a freezing method with ultra-fast cooling rates. Upon contact with liquid nitrogen, the intracellular water transitions into a glass-like (vitrified) state without forming ice crystals. Ice crystal formation is the leading cause of loss of cell viability if freezing is attempted with no special cryoprotectants or techniques. In vitrification, commercially developed media are used to replace a part of intracellular water with cryoprotectants. In this way, cells have additional protection from cryogenic damage. After incubation in a cryoprotectant solution, the oocytes or embryos are placed onto special devices (the so-called straws) and directly submerged into liquid nitrogen. The technique is highly reliable, yielding more than 95% preserved viability and development potential, both in embryos and oocytes.
Through the ‘Keep Hope Alive’ project, Nadezhda Hospital is actively engaged in fertility preservation for cancer patients and patients with autoimmune and rheumatoid diseases.