The position of the embryo on the right side of the uterine horn may be caused by gynecological diseases, inflammation of the tubal lumen or the surrounding area, and imbalance in the secretion of estrogen and progesterone. 1. Gynecological diseases: if endometritis, endometrial polyps, cervicitis, etc. occur, it will affect the normal endometrial lining of the uterus, resulting in the fertilized egg in the uterine corner of the uterus to bed and develop. 2. Inflammation of the tubal lumen or the surrounding area: this can lead to poor lumen patency, affecting the normal operation of the pregnant egg and causing it to be deposited in the uterine horn. 3. Imbalance of estrogen and progesterone secretion: the normal function of fallopian tube needs estrogen and progesterone to regulate. If there is an imbalance in estrogen and progesterone secretion, it will easily lead to the fertilized egg not being able to land in the normal position, resulting in the embryo’s position being on the right side of the uterine horn. If the embryo is located on the right side of the uterine horn, it is necessary to strengthen the review. If the gestational sac settles in the uterine horn, it belongs to a kind of ectopic pregnancy, which needs to be treated conservatively or surgically in time to prevent rupture of the gestational sac and bleeding.