Ovarian reserve remains reduced two years after breast cancer chemotherapy

A combined retrospective and prospective cohort study in Human Reproduction assessed ovarian reserve after chemotherapy in 152 women aged 18–42 years receiving fertility preservation counselling at Copenhagen University Hospital between 2018 and 2023. Of these, 57 underwent unilateral ovarian tissue cryopreservation (OTC), 41 underwent oocyte or embryo cryopreservation, and 54 had no fertility preservation. Anti-Müllerian hormone (AMH) and antral follicle count (AFC) were measured before chemotherapy and at 6, 12, and 24 months afterward.

Both markers declined markedly, with partial recovery over two years. After adjustment for baseline age and hormonal contraceptive use, median AMH was reduced from baseline by 90% (95% CI 85–93%) at six months and 75% (63–83%) at 24 months in women without OTC. Corresponding reductions among women with OTC were 93% (85–95%) and 85% (78–90%). AFC showed similar but less pronounced changes. Reductions were greater and recovery more limited among women aged 35 years or older.

The findings may inform counselling about chemotherapy-related ovarian damage, but the observational design cannot establish that OTC caused the differences between groups. AMH and AFC describe ovarian reserve rather than pregnancy or live-birth outcomes. Follow-up assessments were incomplete, and natural age-related decline may have contributed. The study received funding from the Independent Research Fund Denmark; disclosed industry relationships had no role in the study.