P–448 Clinical outcome of social oocyte cryopreservation at advanced age

Abstract

Abstract Study question What are the success rates of social oocyte cryopreservation (SOC) at advanced age? Summary answer In this study, one in four women who underwent SOC above age 35 had a delivery. What is known already While SOC is gaining popularity, reports on delivery rates are limited due to low utilization rates. Study design, size, duration Retrospective data collection of all woman who underwent SOC between 2011–2018, and presented for treatment using cryopreserved oocytes until January 2021. Participants/materials, setting, methods: Review of patient records (including both IVF and antenatal/postnatal) and laboratory data in a university affiliated hospital-based IVF unit. Main results and the role of chance: A total of 448 women underwent SOC during 2011–2018. 50 (11.2%) women returned to use these oocytes until the end of January 2021. Women who returned to use their oocytes underwent cryopreservation at mean age of 38.2±2.2. 46 (92%) of participants were above 35 at time of cryopreservation. Number of oocytes cryopreserved was 11.3±9.7. Mean time from cryopreservation to thawing was 5.5±1.8years (range 1–9 years). and age at thawing was 43.4±2.1 (range 40–49). Nearly half of patients initially attempted to conceive before using their cryopreserved oocytes, mostly by ART using fresh oocytes. Mean number of oocytes thawed and oocytes survived per women was 9.7±6.2 and 6.1±4.9 respectively (post thawing survival rate 65.4±35%). Mean number of embryos transferred, at one or more attempts was 2.6±2.1 per women. Eleven women gave birth or had an ongoing pregnancy > 20 weeks at time of analysis. All deliveries resulted from cryopreservation at age 36 and older (delivery rate 23.9% per women). Limitations, reasons for caution: We report our initial experience of women who underwent SOC at a single center. Most women who returned to use their oocytes had undergone SOC at advanced age, therefore not necessarily reflecting outcome for younger patients attempting to preserve fertility using this technology. Wider implications of the findings: Considering modest success rates of SOC in our cohort, women considering SOC are advised to do so at an earlier age. Trial registration number Not applicable