Background: The aim of this study was to evaluate the effects of breast cancer on the ovarian response and on oocyte quality following controlled ovarian hyperstimulation (COH). Methods: This retrospective case-control study evaluated the effects of breast cancer on the ovarian response and on the oocyte quality. Oncological patients with breast cancer undergoing controlled ovarian stimulation cycles for fertility preservation, and age- and date-matched controls undergoing COH for in vitro fertilization (IVF) for male or tubal factor infertility were included in the study. Two hundred and ninety-four women were enrolled: 105 affected by breast cancer and 189 healthy women in the control group. Both groups were comparable in terms of age, BMI, and AMH value. Maximal estradiol levels on the triggering day, duration of stimulation, total amount of gonadotropins administered, number of oocytes retrieved, rate of metaphase 2 oocyte production, and numbers of immature and dysmorphic oocytes were analyzed. Results: Considering factors influencing the oocyte quality, such as age, BMI, AMH, duration of stimulation, E2 level on the triggering day, total FSH cumulative dose, stage, histotype, BRCA status, and hormone receptors, the univariate and multivariate analyses identified breast cancer as a risk factor for the presence of dysmorphic oocytes. Conclusions: The diagnosis of breast cancer does not seem to be associated with the impairment of the ovarian reserve, but is linked to a worsening oocyte quality.

Background: Preserving fertility in young women with cancer is crucial for comprehensive care. Based on GBD 2023 estimates, approximately 1000 women aged 15–39 are diagnosed with haematological malignancies annually in Italy. Guidelines recommend timely fertility preservation (FP) counselling for all at-risk patients, yet real-world access data remain limited. Methods: This multicentre, retrospective observational study analysed FP counselling for women aged 15–39 with haematological malignancies from 2015 to 2023. Counselling data were extracted from the Italian Assisted Reproductive Technology Registry (IARTR). This data collection system, known as PreFerIta, was developed within a project supported by the Italian Ministry of Health to collect data on Fertility Preservation (FP) treatments in oncology patients and/or those at risk of iatrogenic infertility, provided in seven specialised ART centres across Italy. The PreFerIta database includes data on both oocyte cryopreservation and ovarian tissue cryopreservation. Annual visits were related to the estimated regional incidence of new haematological malignancies (GBD 2023). Counselling-to-incidence ratios, absolute/relative gaps, and 95% confidence intervals (CIs) were calculated. Results: From 2015 to 2023, an estimated 4473 new haematological malignancies occurred in the catchment regions. Concurrently, 1200 FP counselling visits were recorded. While incidence modestly declined, counselling activity remained high. The counselling-to-incidence ratio increased from 17.33% in 2015 to 31.92% in 2018, stabilising between 26% and 31% thereafter (30.98% in 2023). The relative counselling gap decreased from 82.67% to 69.02%. These ratios represent lower-bound estimates of access to specialised oncofertility consultations. Conclusions: In this Italian network, approximately one in four to one in three incident haematological malignancies in young women were associated with specialised FP counselling. This reflects a substantial integration of oncofertility services into haematology care, highlighting opportunities to further strengthen referral pathways and achieve full guideline concordance.