Mr. Li and his wife have been married for more than a year and have had two spontaneous miscarriages. The couple was quite anxious and came to our center for examination. The woman’s test results did not reveal any special abnormalities, but the man’s semen test revealed that Mr. Li’s sperm DNA fragmentation rate was as high as 75.6%. The doctor told Mr. Li that the high sperm DNA fragmentation rate might be the culprit of his wife’s miscarriage. A high sperm DNA fragmentation rate and compromised sperm DNA integrity may lead to poor embryo quality and recurrent miscarriages. Therefore, it is not customary to blame women for miscarriages, but men should also introspect that poor sperm quality may also lead to recurrent miscarriages. Sperm DNA is an important indicator of sperm maturity. The structural and functional integrity of sperm DNA is not only crucial to maintaining male fertility, but also to the health of the offspring. Although it is possible for some sperm with damaged DNA to form a protoplast during fertilization, undergo early oogenesis and eventually develop into a normal embryo, the proportion of sperm with such DNA damage, if above 30%, may lead to a significant decrease in egg fertilization rate and become an important factor in male infertility. Sometimes, although embryos can successfully implant, most of them will undergo spontaneous abortion at an early stage and eventually lead to pregnancy failure. Therefore, a high rate of sperm DNA fragmentation may be the culprit in many couples with “unexplained” miscarriages. The existing routine semen tests include sperm count, density and motility, which fluctuate widely, making it difficult to make accurate and effective judgments and predictions about sperm quality and pregnancy outcomes in assisted reproduction. Studies and clinical practice have found that infertile men have high sperm DNA fragmentation rates and impaired sperm DNA integrity, which not only seriously affects the fertilization ability of sperm in assisted reproduction and the formation of post-fertilization prokaryotic nuclei, but also may lead to abortion of the pregnant fetus and even the birth of congenital malformed children. Therefore, testing for sperm DNA fragmentation is particularly important for couples with recurrent miscarriages. In addition, for some men who want to undergo eugenics testing before pregnancy, sperm DNA fragmentation testing can also be performed to detect and treat problems early. Patients with high sperm DNA fragmentation rate may have poor lifestyle habits such as staying up late, smoking, alcohol abuse, or working in high temperature, toxic and radioactive environments for a long time, or with reproductive gland infections such as epididymitis, orchitis, prostatitis or seminal vesiculitis, or with varicocele, among other factors. So, how to reduce the rate of sperm DNA fragmentation? The doctor gave Mr. Li tips: firstly, he should correct his bad habits such as staying up late and smoking; secondly, he should improve or avoid harmful working environment such as high temperature, toxic and radiation exposure; furthermore, he should strengthen antioxidant therapy including high-dose application of Vit C and Vit E, supplementation of trace elements such as zinc and selenium, and use of levocarnitine; finally, he should actively treat primary diseases such as gonadal infections, spermatic cord Varicose veins, etc. All these measures may reduce the rate of sperm DNA fragmentation and help patients to achieve their wish of having a healthy baby.