Fertility Preservation Success Subsequent to Concurrent Aromatase Inhibitor Treatment and Ovarian Stimulation in Women With Breast Cancer

Purpose We have previously reported an approach to ovarian stimulation for the purpose of fertility preservation (FP) in women with breast cancer via embryo freezing with the concurrent use of letrozole. The aim of this study was to provide the pregnancy and FP outcomes when embryos generated with the same protocol are used. Patients and Methods In all, 131 women with stage ≤ 3 breast cancer underwent ovarian stimulation and received concurrent letrozole 5 mg per day before receiving adjuvant chemotherapy and cryopreserving embryos. Results Thirty-three of the 131 women underwent 40 attempts to transfer embryos to their own uterus (n = 18) or via the use of a gestational carrier (n = 22) at a mean age of 41.5 ± 4.3 years with a median 5.25 years after embryo cryopreservation. The overall live birth rate per embryo transfer was similar to the US national mean among infertile women of a similar age undergoing in vitro fertilization–embryo transfer (45.0 v 38.2; P = .2). Seven (38.8%) of the 18 pregnancies were twins with no higher-order pregnancies being encountered. No fetal anomalies or malformations were reported in 25 children after a mean follow-up of 40.4 ± 26.4 months. Seventeen of the 33 women attempting pregnancy had at least one child, translating into an FP rate of 51.5% per attempting woman. Conclusion Embryo cryopreservation after ovarian stimulation with the letrozole and follicle-stimulating hormone protocol preserves fertility in women with breast cancer and results in pregnancy rates comparable to those expected in a noncancer population undergoing in vitro fertilization.