[Ultrasonographic detection and clinical importance of placental migration (author's transl)].

Pathological insertions were diagnosed in 66 of 4, 804 ultrasonic placentograms, beginning with the 13th week of pregnancy. Placental migration, that is displacement towards the fundus of the uterus of the caudal adge of the placenta, was followed up by consecutive checks. Pathological placenta locations were recorded in 4.1 per cent of all cases, up to the 20th week of pregnancy, was found to emanate from migration in the majority of all cases. The process of placental migration usually takes place up to the 30th week of pregnancy and is completed by the 35th week. If pathological insertions were diagnosed after the 20th week f pregnancy, migration was found to take place with much lower incidence. Methodical problems relating to ultrasonographic representation are discussed together with clinical consequences.