Reproductive outcomes from ten years of elective oocyte cryopreservation.

RESEARCH QUESTION: To assess the relationship between the number of oocytes retrieved during elective oocyte cryopreservation (EOC) cycles with various clinical, biochemical, and radiological markers, including age, body mass index (BMI), baseline anti-Müllerian hormone (AMH), antral follicle count (AFC), Oestradiol level (E2) and total number of follicles ≥ 12 mm on the day of trigger. To also report the reproductive outcomes from women who underwent EOC. METHODS: A retrospective cohort of 373 women embarking on EOC and autologous oocyte thaw cycles between 2008 and 2018 from a single London clinic in the United Kingdom. RESULTS: 483 stimulation cycles were undertaken amongst 373 women. The median (range) age at cryopreservation was 38 (26-47) years old. The median numbers of oocytes retrieved per cycle was 8 (0-37) and the median total oocytes cryopreserved per woman was 8 (0-45). BMI, E2 level and number of follicles ≥ 12 mm at trigger were all significant predictors of oocyte yield. Multivariate analysis confirmed there was no significant relationship between AFC or AMH, whilst on univariate analysis statistical significance was proven. Thirty six women returned to use their cryopreserved oocytes, of which there were 41 autologous oocyte thaw cycles undertaken. There were 12 successful livebirths achieved by 11 women. The overall livebirth rate was 26.8% per cycle. No livebirths were achieved in women who underwent EOC ≥ 40 years old, and 82% of all livebirths were achieved in women who had done so between 36 and 39 years old. CONCLUSION: Clinical, biochemical and radiological markers can predict oocyte yield in EOC cycles. Reproductive outcomes are more favourable when cryopreservation is performed before the age of 36, with lower success rates of livebirth observed in women aged 40 years and above.

Oocyte yield in social, medical and donor oocyte cryopreservation cycles.

To determine if oocyte yield in women undergoing cryopreservation for social (SOC), medical (MOC) and oocyte donation (OD) cycles is comparable when matched for age. 315 oocyte retrievals were performed for SOC, 116 for MOC and 392 for OD. Non-parametric Kruskal-Wallis tests and Poisson regression were used to assess the impact of age stratification. The median ages of women undergoing SOC, MOC, and OD were 38, 31 and 26 years respectively. The median (IQR) number of oocytes in the three categories was 7, 10, and 12. The oocyte yield was significantly higher in women aged 30-34 years undergoing SOC, compared to the MOC group. For the SOC group, age in years, oestradiol levels per 1000 pmol/and follicle count >12mm on the day of trigger were significant predictors of oocyte yield. Women embarking on SOC are significantly older than those undergoing MOC and OD, and thus oocyte yield is reduced when stratified for age. This study highlights the significant predictors of oocyte yield amongst women undergoing oocyte cryopreservation for specific indications. The findings can be used to optimise the yield and overall chance of successful livebirth.