[Indications of ultrasonography in perinatal medicine (author's transl)]

The indications of ultrasonography in obstetrics are shortly discussed. The advantage of the method is primarily the exact dating of the pregnancy either by measuring the crown-rump-length during the 8th and 12th week of pregnancy, or the measurement of the biparietal diameter between the 15th and 21st week. These data form the basis fo the interpretation of different hormonal findings during pregnancy such as HPL or estriol. In combination head and abdominal fetal measurements inform about the fetal intrauterine development and the fetal body weight. From both parameters and the head to abdominal ratio fetuses at risk to either small-for-date-babies or large-for-data-babies can be diagnosed with high accuracy. The demonstration of anatomical fetal details makes it possible to diagnose malformations in early stages of pregnancy. This enables us to choose in cooperation with the perinatologist and pediatric surgeon the optimal time for selective cesarean for further treatment of the intrauterine patient.