Abstract:

In assisted reproductive technology, the low-grade cleavage embryo (LGCE) is associated with a lower probability of developing into viable blastocysts, making it difficult to achieve satisfactory outcomes. We report a case of a 35-year-old male patient with cryptozoospermia who sought medical attention after more than two years of unprotected intercourse without conception while attempting to have a second child. He was diagnosed with secondary male infertility. His 31-year-old spouse underwent assisted reproductive technology with him. In the first oocyte retrieval cycle, 16 oocytes were retrieved, and 10 underwent intracytoplasmic sperm injection (ICSI). On Day 3, all embryos were LGCE (Grade Ⅲ-Ⅳ), and no viable blastocysts were formed following blastocyst culture. In the second oocyte retrieval cycle, 18 oocytes were retrieved, and 11 underwent ICSI. On Day 3, the embryos remained LGCE. Two fresh embryos were transferred, but did not result in pregnancy. The remaining embryos underwent blastocyst culture, and laser-assisted hatching (LAH) was employed to improve LGCE blastocyst formation, ultimately resulting in one 3BC-grade blastocyst that was cryopreserved. A live birth was subsequently achieved following a frozen-thawed embryo transfer cycle. By summarizing the management of this patient's LGCE, we explore the laboratory strategy to improve the blastocyst formation of LGCE in patients with cryptozoospermia, and to enhance their chances of pregnancy.

Key words: Laser-assisted hatching, Low-grade cleavage embryo, Cryptozoospermia, Sperm injections, intracytoplasmic, Pregnancy