title: Initiation of spontaneous labor.
mesh_terms: D000818:Animals; D004717:Endometrium / Q000378:metabolism; D004967:Estrogens / Q000378:metabolism / Q000502:physiology; D005260:Female; D006801:Humans; D007745:Labor Onset; D007743:Labor, Obstetric; D009130:Muscle, Smooth / Q000378:metabolism; D010121:Oxytocin / Q000502:physiology; D010920:Placenta / Q000201:enzymology / Q000378:metabolism; D011247:Pregnancy; D011374:Progesterone / Q000378:metabolism / Q000502:physiology; D011453:Prostaglandins / Q000096:biosynthesis / Q000502:physiology*; D051381:Rats; D012756:Sheep; D013254:Steroid 17-alpha-Hydroxylase / Q000378:metabolism; D014599:Uterus / Q000378:metabolism
chemical_list: D004967:Estrogens; D011453:Prostaglandins; D011374:Progesterone; D010121:Oxytocin; D013254:Steroid 17-alpha-Hydroxylase