Fertility Preservation (FP) Strategies and Long-Term Reproductive Outcomes in Women With Breast Cancer

Authors: Pietro Santulli; M. Bourdon; C. Weinstein; V. Barraud Lange; F. Coussy; L. Melka; C. Maignien; J. Gonnot; K. Pocate Cheriet; C. Chapron

Fertility preservation (FP) is increasingly becoming a part of breast cancer management, as treatments can impair fertility. Options include controlled ovarian stimulation (COS), in vitro maturation (IVM), and ovarian tissue cryopreservation (OTC), but the best approach remains debated due to factors like treatment urgency, hormone sensitivity, and gonadotoxicity. Real‑life data on pregnancy, live birth outcomes, and use of cryopreserved material are still limited.

This single-center retrospective cohort study evaluated fertility preservation (FP) strategies used in women with breast cancer and their long-term reproductive outcomes. The study included 165 women aged 18–40 years who were referred for fertility preservation counseling between 2015 and 2019 at a tertiary care center. Fertility preservation options included controlled ovarian stimulation (COS) or in vitro maturation (IVM) with oocyte and/or embryo vitrification, ovarian tissue cryopreservation (OTC), or combinations of these approaches. Long-term follow-up of at least five years assessed ovarian function, pregnancy intentions, conception methods, and reproductive outcomes. The mean age of the participants was 33.2 ± 3.9 years. Chemotherapy was administered in the adjuvant setting to 78 women (47.3%) and in the neoadjuvant setting to 68 (41.2%), while 19 women (11.5%) did not receive chemotherapy. A fertility preservation strategy was offered to 151 women (91.5%) and was performed in 123 (74.5%). Controlled ovarian stimulation was the most commonly used technique (40.6%), followed by in vitro maturation (33.3%) and ovarian tissue cryopreservation (5.4%). Forty-two women (25.5%) did not undergo fertility preservation.

Long-term follow-up data were available for 94 women (57.0%). Among these, 45 (47.9%) attempted pregnancy. Clinical pregnancy was achieved by 29 women (64.4%), and 27 (60.0%) had a live birth. Of the women who had a live birth, 18 (66.7%) conceived spontaneously, while 9 (33.3%) achieved a live birth through assisted reproductive technologies (ART). Cryopreserved reproductive material was used by 9 of the 45 women attempting pregnancy (20.0%), resulting in 2 live births. Women who attempted pregnancy were more likely to have hormone receptor-negative breast cancer, receive less adjuvant chemotherapy, report regular menstrual cycles, and undergo embryo cryopreservation than women without pregnancy intentions. The study was limited by its single-center design, loss to follow-up, incomplete long-term ovarian reserve data, reliance on self-reported outcomes, and the absence of a control group.

Overall, fertility preservation was feasible in women with breast cancer, and after more than five years, nearly half attempted pregnancy, with 60% achieving a live birth, most commonly through spontaneous conception.

Who Returns to Use Their Eggs? Factors Associated with Oocyte Utilization After Medical Fertility Preservation

Authors: Camille Felicioli; C. Sonigo; M. Grynberg; F. Eustache; C. Sifer; M. Peigné

Data on oocyte utilization after medical fertility preservation are scarce, and existing studies consistently report low use. Utilization rates appear higher in non‑oncological indications than in oncological ones, but no study has yet examined predictive factors in medical settings. In elective fertility preservation, predictors of utilization have been reported, including a low number of vitrified oocytes and advanced age over 38 years.

This retrospective single-center study evaluated predictors of vitrified oocyte utilization after medical fertility preservation. The study included 1,787 women who underwent oocyte cryopreservation for medical fertility preservation at Jean Verdier University Hospital, France, between January 2013 and December 2021. Women who underwent controlled ovarian stimulation or in vitro maturation were included. Clinical, biological, reproductive, and socio-demographic characteristics at the time of cryopreservation were analyzed. Oocyte utilization was assessed through December 2024, and predictive factors were identified using Cox regression models. Among the participants, 60% underwent fertility preservation for benign conditions, mainly endometriosis, and 40% for malignant conditions, primarily breast cancer and hematologic malignancies. During follow-up, 254 women (14.2%) returned to use their vitrified oocytes. The cumulative utilization rate reached 19.3% (95% confidence interval [CI] 17.4–21.9%) at 8 years after cryopreservation. Utilization was significantly higher among women older than 36 years, those with diminished ovarian reserve, and those with benign indications.

Women who used their oocytes were generally older at the time of cryopreservation, had lower ovarian reserve markers, and had a higher socioeconomic status. In multivariable analysis, age older than 36 years (hazard ratio [HR] 2.1) and anti-Müllerian hormone (AMH) levels below 1.2 ng/mL (HR 1.58) were independently associated with increased oocyte utilization. In contrast, previous childbirth (HR 0.67) and retrieval of fewer than 7 oocytes (HR 0.70) were associated with lower utilization rates. Among the women who returned to the study center, 227 underwent warming of 2,995 oocytes, resulting in 71 live births. The live birth rate per warmed oocyte was 1.4% following in vitro maturation and 2.5% following ovarian stimulation, regardless of age or fertility preservation indication. The study was limited by its retrospective, single-center design and varying follow-up durations, which may have underestimated utilization among younger women who had not yet attempted pregnancy.

Overall, older age and diminished ovarian reserve at the time of cryopreservation were associated with greater use of vitrified oocytes, whereas previous childbirth and a lower oocyte yield were associated with reduced utilization.

ESHRE 2026, July 5^th-8^th, London, UK.