Objective: To assess the relationship between number of oocytes retrieved during social egg freezing (SEF) cycles with various clinical, biochemical and radiological markers; e.g. age, body mass index (BMI), baseline anti-Mullerian hormone (AMH), antral follicle count (AFC), Oestradiol level (E2) and total number of follicles ≥12mm at trigger. Main outcome measures: To describe the characteristics and outcomes of women who underwent SEF. Methods: A retrospective cohort of women embarking on SEF between 2008 and 2018 from a single London UK fertility clinic. Results: 483 stimulation cycles were undertaken in 373 women. The median age at freeze was 38 (26-47) years. The median numbers of oocytes retrieved per cycle was 8 (0-37), and total oocytes cryopreserved 8 (0-45) per woman. BMI, E2 level and number of follicles ≥12mm at trigger were all significant predictors of oocyte yield. Multivariate analysis confirmed no significant relationship between AFC or AMH, whilst on univariate analysis statistical significance was proven. 36 women returned to use their oocytes, with 41 autologous egg thaw cycles undertaken. 12 successful livebirths were achieved by 11 women. The overall livebirth rate was 26.8% per cycle. No livebirths occurred in women ≥40 years old and 82% of all livebirths were in women aged 36-39 at freeze. Conclusions: This study demonstrates clinical, biochemical and radiological markers can predict oocyte yield in SEF cycles. However, subsequent reproductive outcomes highlight women embarking upon SEF should be encouraged to do so before the age of 37 years, and no later than 40 to optimise successful livebirth.