[Pathological positioning of the placenta at 20 weeks' gestation--its significance for the course of the pregnancy and labor].

The authors found pathologically located placenta in 5.2% of pregnant women during ultrasound examinations at 20 weeks' gestation. The pregnant women were examined periodically by the echograph every 4 weeks. Hundred women with normal localization of the placenta were included in the control group. There were 5-fold more frequent bleedings in the investigated group as 86.5% of bleedings were manifested for the first time after 20 weeks' gestation. The frequency and strength of bleedings were in close connection with the gravity of the pathological insertion. Asymptomatically progressing pregnancies with abnormally localized placenta were 66%. The authors found percentage dependence of pathological placental localization on the gestational period and the possibility for reliable diagnosis. They recommend follow-up of placental localization dynamically till the end of pregnancy on the basis of the possibility for a change in placental localization and its significance for the course of pregnancy and delivery.