Live birth rate after use of cryopreserved oocytes or embryos at the time of cancer diagnosis in female survivors: a retrospective study of ten years of experience

Abstract

Purpose: The aim of this study was to evaluate the outcomes of frozen oocytes or embryos cryopreserved after controlled ovarian stimulation (COS) or in vitro maturation (IVM) for female cancer patients who underwent a fertility preservation (FP) prior to gonadotoxic therapy.

Methods: A retrospective cohort study from 2009 to December 2017 was conducted. Among the 667 female cancer patients who underwent oocytes or embryos cryopreservation for FP, 40 (6%) have returned to the fertility clinic between 2011 and 2019 to use their frozen material after being cured. We compared these thaw cycles outcomes according to the techniques used at the time of cryopreservation.

Results: Among the 40 women cancer survivors who used their cryopreserved material, thirty patients have benefited from at least one embryo transfer. Ten patients did not have an embryo transfer since the oocytes did not survive after the thawing process or because no embryo was obtained after fertilization. We related three live births following FP using IVM (two from frozen oocytes and one after embryo cryopreservation). Five live births were obtained when COS was performed at the time of FP (one from frozen oocytes and four after embryo cryopreservation).

Conclusions: Our preliminary results, although they are obtained in a small sample, are encouraging and show that different FP techniques can be used in female cancer patients and lead to live births. IVM is one of the options available that does not delay the start of chemotherapy or if ovarian stimulation using gonadotropins is contraindicated.

Keywords: In vitro maturation; Live birth; Oncofertility preservation; Oocyte cryopreservation; Zygote cryopreservation.

Fig. 1

Flowchart of the study; 667 female patients underwent our FP program before a gonadotoxic treatment from January 2009 to October 2017. Forty patients cured from cancer asked for the use of oocytes or embryos cryopreserved in this context. We divided this population into four groups according to FP technique performed: oocyte or zygote cryopreservation after COS (OO-COS and ZYG-COS) or after IVM (OO-IVM and ZYG-IVM). COS, controlled ovarian stimulation; IVM, in vitro maturation; OO-COS, oocytes cryopreserved after controlled ovarian stimulation; OO-IVM, oocytes cryopreserved after in vitro maturation; ZYG-COS, zygotes cryopreserved after controlled ovarian stimulation; ZYG-IVM, zygotes cryopreserved after in vitro maturation