If the endometrium is only 7mm at the time of ovulation, the chance of fertilization is very low. It is recommended to find out the reason, under normal circumstances, the endometrium should reach 9mm at least during the ovulation period for the fertilized egg to be able to implant, and blood can be drawn to check the sex hormone six to see if the estrogen is normal, and to know if the ovary function is normal, and according to the result, corresponding treatment should be given. In addition, if you have a history of abortion or uterus removal surgery, after the surgery, menstrual flow has been significantly reduced, to suspect the possibility of incomplete adhesion of the uterine cavity, it is recommended that, if necessary, combined with the clinical history of the need to do a hysteroscopy to find out whether there is a uterine cavity adhesion, and if there are adhesions need to be separated.