Technical points influencing the choice of an ultrasonic "B" scanner for obstetric use.
D005260:Female; D006801:Humans; D008722:Methods; D009774:Obstetrics / Q000295:instrumentation*; D010920:Placenta; D010923:Placenta Previa / Q000175:diagnosis; D011247:Pregnancy; D014465:Ultrasonics / Q000295:instrumentation*