title: Sonar in the first trimester of pregnancy.
mesh_terms: D000022:Abortion, Spontaneous / Q000175:diagnosis*; D000033:Abortion, Threatened / Q000175:diagnosis; D010064:Embryo Implantation; D005260:Female; D005333:Fetus / Q000502:physiology; D005865:Gestational Age; D006128:Growth; D006801:Humans; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011295:Prenatal Care; D011296:Prenatal Diagnosis; D011446:Prospective Studies; D012044:Regression Analysis; D014463:Ultrasonography; D014592:Uterine Hemorrhage / Q000150:complications; D014599:Uterus / Q000033:anatomy & histology / Q000254:growth & development / Q000473:pathology; D014817:Vitelline Membrane / Q000254:growth & development / Q000473:pathology