This randomized controlled trial aims to evaluate whether supplementation with exogenous luteinizing hormone (LH) can improve embryo quality in patients undergoing in vitro fertilization (IVF) with a long gonadotropin-releasing hormone agonist (GnRH-a) protocol who have excessive suppression of LH. Eligible participants will be randomly assigned to receive either exogenous LH supplementation or standard care. The primary outcome is embryo quality, and secondary outcomes include pregnancy rates and safety assessments. The study is conducted at Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University.