Corion Fertility Clinic

Oocyte Cryopreservation

At Corion, we provide the facility of Oocyte Cryopreservation in co-ordination with Graces Cryo Bank. Oocyte Cryopreservation also called as Egg Freezing, involves stimulating, extracting, freezing, and storing a woman’s eggs (oocytes). These eggs can be thawed months, or even years, later and fertilized to create embryos. The embryos can then be transferred to the uterus so as to achieve a successful pregnancy. Egg freezing depends upon egg production, which is based on the number of eggs that are reserved in ovaries of a female and how they will respond to the medications used during stimulation. Following factors play an important role whenever we counsel a patient or a donor for oocyte freezing:

  • Age of the Female
  • Baseline Level of FSH (Follicle Stimulating Hormone) & E2 (Estradiol)
  • "Resting" ovarian follicle Count

Oocyte Cryopreservation is carried out at Corion not only for Oocyte Donors who are recruited in our Donor Egg program but also recommended for :

  • Oncological and non-oncological patients who are going to receive treatment that is toxic to gonads
  • Women who wish to delay motherhood due to career choices, continuing education, not having a partner, or for other personal or medical reasons, as freezing healthy eggs at an early age may optimize chances for future fertility. It also helps to reduce the risks of chromosomal abnormalities which might arise at higher age
  • To accumulate oocytes in low response patients
  • Avoiding the ethical and legal dilemmas surrounding the freezing of embryos
  • Women who have had repeated ovarian surgery which leads to a depletion of the follicular reserve, making premature ovarian failure more likely patients for whom we would prefer to carry out embryo transfer in a cycle other than the one in which follicle stimulation is carried out (might be due to OHSS, development of polyps, hydrosalpinx or hydrometra, absence of spermatozoa, etc.)
  • Women who wish to donate their eggs for others as part of a donor egg bank

Stages of Oocyte Cryopreservation Procedure

  • The candidates for oocyte freezing either a patient or a donor, is advised to undergo initial infectious disease screening tests like HIV I-II, Hepatitis C, Hepatitis B surface antigen & VDRL
  • Ovarian Stimulation : This stage entails stimulation of the ovary(s) to obtain multiple follicle growth and egg production. When a sufficient number of follicles have achieved satisfactory growth, the final, follicular maturation phase is induced with a trigger shot of hCG
  • Oocyte Retrieval: This is done by needle aspiration through the vaginal wall under ultrasound guidance & general anesthesia
  • Oocyte Vitrification : After around 80-90 mins of retrieval, denuded oocytes which show a proper grade of maturation (metaphase II) are cryo-stored by vitrification and immediately plunged in liquid nitrogen
  • Apart from the patients, all donor oocytes are quarantined for 6 months prior to release for ICSI to confirm it is free from infectious diseases
  • After thawing of the frozen eggs, fertilization will be carried out by ICSI (intracytoplasmic sperm injection), irrespective of the quality of the semen. The survival rate of the oocytes after thawing is reported as high as 85%

No statistically significant differences were observed, in comparison to a group of fresh oocytes, either in the rate of fertilisation or in embryo quality.

To avail to our Oocyte Cryopreservation Services, kindly write to