Breast cancer, the most frequently diagnosed and reported cause of death, threatens women’s health in many countries.[1] Certain factors play an important role in protecting against breast cancer development, including late menarche and more nursing duration.[2–4] Ovarian hormone exposure, the number of ovulatory cycles, and breast lobular differentiation are suggested to reduce the occurrence of breast cancer.[5–7] Researchers have evaluated the effects of reproductive factors on BRCA-related breast cancer, but the results are conflicting and differ by mutations either in BRCA1 or BRCA2. This evidence concerns the gene BRCA1 and breast cancer.