The use of ultrasound in obstetrics.
D000033:Abortion, Threatened / Q000175:diagnosis; D000013:Congenital Abnormalities / Q000175:diagnosis; D005260:Female; D005323:Fetal Monitoring; D005865:Gestational Age; D006801:Humans; D006828:Hydatidiform Mole / Q000175:diagnosis; D007746:Labor Presentation; D010920:Placenta; D011247:Pregnancy; D011248:Pregnancy Complications / Q000175:diagnosis*; D011261:Pregnancy Trimester, First; D011263:Pregnancy Trimester, Third; D011271:Pregnancy, Ectopic / Q000175:diagnosis; D011272:Pregnancy, Multiple; D014463:Ultrasonography