Fertility preservation after fertility-sparing surgery in women with borderline ovarian tumours

International audienceObjective: To present a case series of women with borderline ovarian tumours (BOTs) who underwent oocyte vitrification in addition to fertility-sparing surgery.Study design: Observational study of all women referred to a French fertility preservation unit between 2015 and 2019 for counselling regarding a fertility preservation (FP) strategy after BOT fertility-sparing surgery. All eligible women underwent one or more cycles of controlled ovarian stimulation (COS) using an antagonist protocol, followed by oocyte retrieval. Metaphase II (MII) oocytes were vitrified.Results: Twenty-five women with BOTs were referred during the study period. Among them, 11 women underwent at least one cycle of COS. One hundred and seven MII oocytes were vitrified. The mean number of vitrified MII oocytes per woman was 9.7 (standard deviation 5.2). Five live births were reported during follow-up of four women with vitrified oocytes: three spontaneous pregnancies, one in-vitro fertilization cycle with fresh embryo transfer, and one live birth after return of vitrified oocytes.Conclusion: Conservative surgery for BOTs offers a high spontaneous pregnancy rate but has a higher risk of relapse than radical treatment. Furthermore, women who undergo conservative BOT surgery have a higher risk of surgery-induced premature ovarian failure. Oocyte cryopreservation after COS appears to be an effective technique after the conservative management of BOTs in women of reproductive age. Although the available short-term data are reassuring, further long-term studies evaluating the safety and cost-effectiveness of this systematic FP strategy after BOT fertility-sparing surgery are required