Outcomes of Social Egg Freezing: A Cohort Study and a Comprehensive Literature Review

Abstract

The purpose of this study is to evaluate the live birth outcome following oocyte thaw in women who underwent social egg freezing at Guy's Hospital, alongside a detailed published literature review to compare published results with the current study. A retrospective cohort study was conducted between January 2016 and March 2022 for all women who underwent egg freezing during this period. Overall, 167 women had 184 social egg freezing cycles. The mean age at freeze was 37.1 years and an average of 9.5 eggs were frozen per retrieval. In total, 16% of the women returned to use their frozen eggs. The mean egg thaw survival rate post egg thaw was 74%. The mean egg fertilisation rate was 67%. The pregnancy rate achieved per embryo transfer was 48% and the live birth rate per embryo transfer was 35%. We also noted that irrespective of age at freezing, a significantly high live birth rate was achieved when the number of eggs frozen per patient was 15 or more. Despite the rapid increase in social egg freezing cycles, the utilisation rate remains low. Pregnancy and live birth rate post thaw are encouraging if eggs are frozen at a younger age and if 15 eggs or more were frozen per patient.

Keywords: elective oocyte cryopreservation; in-vitro fertilization; live birth rate; pregnancy; social egg freezing; vitrification.

Figure 1

Selection process for the study.

Figure 2

Uniform rise in egg freezing cycles depicted during January 2016–March 2022.

Figure 3

Relationship between number and age of women freezing eggs with average number of eggs frozen.