[Frequency and distribution of breech presentation during pregnancy and labor (authors transl)].

On 975 pregnant women treated and delivered during 1973 at the Heidelberg University department of obstetrics 3780 ultrasound examinations were carried out. The frequency of breech presentation related to the duration of pregnancy and the likelyhood of breech presentation at term were calculated. Breech presentation can be seen as physiologic in 70% of early pregnancies. After the 33rd week it is below 10%, after the 38th week 4%. The probability of breech presentation at term at nay given stage before the 30th week is below 10%. After de 31st week this rises steeply up to a maximum of 66% after the 37th week. These influences of parity on these 2 data are described. The relationship between a low placenta and breech presentation is mentioned. These results are discussed.