Ultrasonographic study of the placenta in vitro.

61 placentae were submitted to a study in vitro after deliveries. The ultrasonographic scanning was performed under the condition of immersing them in water and then comparing their images with the anatomical structure by cutting the placentae corresponding to the scanning line. Histological examinations were performed to confirm the anatomical structure. The ultrasonographic findings were classified in 5 types and their correlation with fetal maturity and fetal distress is discussed.