The prerequisite for successful fertilization is the need for normal eggs and sperm. When the ovary ovulates, the umbilical end of the fallopian tube grabs it and temporarily settles the egg inside the fallopian tube, which is commonly located in the juxtapical part of the fallopian tube. At this time, if after a normal sex life, the sperm smoothly from the uterine cavity into the fallopian tube, the sperm continue to swim and meet with the egg in the abdomen of the jugular, after a certain reaction to form a fertilized egg, fertilized egg after a certain period of time to develop into a blastocyst. After a certain period of time, the fertilized egg develops into a blastocyst. When the blastocyst gradually moves from the fallopian tube to the uterine cavity, at this time, due to the influence of oestrogen and progesterone, the endometrium in the uterine cavity gradually evolves into a metamorphosis, and then the blastocyst, after a certain period of change, is successfully buried in the metamorphosis of the endometrium, and then gradually develops and successfully conceives.