title: Ultrasound in the first trimester of pregnancy.
mesh_terms: D010064:Embryo Implantation; D004622:Embryo, Mammalian / Q000033:anatomy & histology; D005321:Extraembryonic Membranes / Q000033:anatomy & histology; D005260:Female; D006801:Humans; D007434:Intrauterine Devices; D007889:Leiomyoma / Q000175:diagnosis; D010920:Placenta / Q000033:anatomy & histology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000175:diagnosis*; D011261:Pregnancy Trimester, First; D011271:Pregnancy, Ectopic / Q000175:diagnosis; D011272:Pregnancy, Multiple; D014328:Trophoblastic Neoplasms / Q000175:diagnosis; D014463:Ultrasonography; D014594:Uterine Neoplasms / Q000175:diagnosis; D014599:Uterus / Q000002:abnormalities; D015017:Yolk Sac / Q000033:anatomy & histology