#391 : Oocyte Cryopreservation — A Five Year Follow Up Study on its Utilization and Outcome

Background & Aim: Oocyte cryopreservation is a boon for women undergoing Assisted reproductive technology (ART). Apart from cancer patients it is recently promoted as a mode of fertility insurance to overcome the age-related decline in fertility, endometriosis, primary ovarian insufficiency, etc. The objective of the study was to evaluate the clinical applications of oocyte freezing and its efficacy in terms of pregnancy outcome. Method: Retrospective observational study of all patients undergoing oocyte cryopreservation from 2016 to 2021 in Lilavati Hospital & Research Centre, Mumbai, India. Result: 221 patients undergoing oocyte cryopreservation were included. Oocyte cryopreservation was done for different indications like azoospermia (50.2%, most common), planned oocyte freezing (41.17%), fertility preservation (1.36%), endometriosis (0.45%), ejaculatory dysfunction (1.8%), husband with active hepatitis B infection (3.62%) and unavailability of husband on the day of egg retrieval (3.62%). A total of 1715 mature oocytes were frozen. 41.17% women were normo-responder, 38.91% were poor responder and 19.90% were hyper-responder. The oocytes of 59 patients (return rate-26.7%) have been thawed and 162 women (73.3%) remain in storage. Out of 508 oocytes frozen for these 59 patients utilizing their oocytes, around 474 oocytes were recovered post-warming (recovery rate 93.3%). A total of 59.3% patients created embryos with a partner, and 40.6% used donor sperm. The mean fertilization rate was 65.8% of surviving oocytes. Of 59 patients, 44 (74.5%) planned a fresh embryo transfer, out of which 20 patients tested positive for pregnancy (pregnancy rate 45.45%). Conclusion(s): We report the outcomes of patients opting for oocyte cryopreservation, which is useful for patient counselling. Limited evidence is available in terms of utilization rate, post warming survival of oocytes, fertilization and pregnancy rate. Further studies over long period of time with larger cohorts are needed.