Recent studies have evaluated the use of magnetic-activated sperm sorting (MASS) to reduce apoptotic spermatozoa and improve the outcome of infertile male with assisted reproductive technology (ART). However, some results were inconsistent with above. The sperm of male with abnormal semen analysis tend to be accompanied with high apoptotic and high DNA fragmentation index (DFI). Hence, this study aimed at determining the efficiency of MASS in improving the clinical outcome of patients with high DFI).

Patients will be recruited from our reproductive medicine center in Nanjing Drum towel Hospital, from July 2019 to July 2020. After semen analysis and selection of infertile men with at least two abnormal sperm parameters and obtaining the informed consent of the patients according to the admission criteria, the patients who enter the project will be randomly divided into the control group (n=30) whose sperm will be screened by density differential centrifugation (DGC) with swim up, and the observation group will be screened by MASS, followed by DGC. Then the procedure of in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) will be performed. Embryo transfer will be underwent according to the developmental speed and morphological characteristics of the embryo. The clinical outcomes after transplantation will be followed up.

Inclusion Criteria:

• Patients were diagnostic as infertile according to 2007 WHO guidelines;
• DFI>25%.

Exclusion Criteria:

• With obvious female infertile factors;
• Sperm count <10 million;
• Chromosomal abnormalities in either or both of the couple;
• Loss of follow up or incomplete information of patients.