Good ovarian function is a crucial factor in the success rate. The reason is that good ovarian function will result in more eggs after ovulation promotion by the doctor, and then in vitro fertilization is more likely to result in more embryos. And in general, the quality of eggs and embryos is relatively good in patients with good ovarian function. But is this true for all patients? In clinical practice, we often see patients with primary infertility (never conceived before) who have good ovarian function and have more than 10 or even 20 eggs retrieved and go back happily. However, when they receive the embryo information, they find that there are only 1-2 embryos of very poor quality or even none at all. This makes the patient feel very unacceptable and frustrated. What are the causes of this situation? Patients with unexplained primary infertility, especially those who have been infertile for a long time, always have some underlying thorny problem that causes infertility and is just not detected. For example, the male partner is of very poor quality with lots of DNA fragmentation, resulting in compromised fertilization rates or compromised embryo quality. Another example is abnormal egg development, where our embryologists look at the patient’s eggs through a microscope and find abnormal egg morphology and malformations, such that the embryonic development potential of the eggs is extremely poor. a clinically valuable study was published in April 2015 in the journal Science, the world’s top authority on natural science and medicine: Dr. McCoy of the University of Washington found that in some patients with repeated Dr. McCoy of the University of Washington found a genetic mutation (a single nucleotide variant (SNP rs2305957) on chromosome 4 of the genome) in some female patients who had repeatedly failed in vitro fertilization. This variant can lead to impaired mitosis, i.e., it may cause chromosomal abnormalities in the embryo. More interestingly, Dr. McCoy performed chromosomal analysis of day 5 embryos (blastocysts) as well as day 3 embryos in this group of female patients with repeated failures and found that the rate of chromosomal abnormalities in day 3 embryos was very high and very few day 5 embryos were present. However, the rate of chromosomal abnormalities in day 5 embryos was significantly lower. This suggests why this group of women has low fertility, and this study also provides us clinicians with an effective strategy on how to address recurrent failure patients: screening for quality embryos through blastocyst culture. To improve the success rate, what do we need to do? 1. maintain a healthy lifestyle and keep the couple in the best physical condition, not too fat or too thin. 2. pay attention to the diet and eat more antioxidant foods, we will provide a menu for patients to pick up at the time of consultation. 3. adhere to the doctor’s prescription for antioxidant vitamins and other complementary medications, it is important to adhere to them and not to stop them at will. 4. We recommend blastoculture to screen for quality embryos and reduce the number of chromosomally abnormal embryos to be implanted. We wish all patients a dream come true and a good pregnancy will come.