title: Ultrasonic detection of combined pregnancies.
mesh_terms: D000293:Adolescent; D000328:Adult; D006063:Chorionic Gonadotropin / Q000097:blood; D005260:Female; D006801:Humans; D011247:Pregnancy; D011274:Pregnancy, Tubal / Q000150:complications / Q000175:diagnosis*; D014463:Ultrasonography
chemical_list: D006063:Chorionic Gonadotropin