[The value of ultrasonic scanning as screening at the 20th week of pregnancy].
D001946:Breech Presentation; D005260:Female; D006801:Humans; D010923:Placenta Previa / Q000175:diagnosis; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011296:Prenatal Diagnosis; D014463:Ultrasonography
Vaerdien af ultralydscanning som screening i 20. svangerskabsuge.