Research [24] has shown that P, as a progesterone, can inhibit uterine contractions, promote the development of the reproductive system, and maintain the continuation of pregnancy; hCG can promote the generation of P in the first trimester, promote the body to secrete estrogen, and reduce the level of oxytocin to inhibit uterine contractions, thus preventing the occurrence of miscarriage; E2 is an estrogen secreted by P that can promote endometrial hyperplasia. Here, OXT is linked to spontaneous abortion.