The onset of labor.
D000818:Animals; D004967:Estrogens / Q000494:pharmacology; D005260:Female; D005333:Fetus / Q000502:physiology*; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism / Q000494:pharmacology; D007745:Labor Onset / Q000187:drug effects; D007743:Labor, Obstetric / Q000187:drug effects; D011247:Pregnancy; D012756:Sheep
D004967:Estrogens; D006854:Hydrocortisone