[Study on placental blood flow in late pregnancy by intravenous 99mTc method].

A method for the continuous recording of uteroplacental blood flow (PBF) in late pregnancies by using 99mTc-albumin has been described. The PBF curve of toxemia of pregnancy has been plotted to indicate small artery spasm in proving ischemic necrosis of placenta. In the PBF of placental insufficiency evidenced by the values for urinary E3, an unfavorable build-up and a delayed build-up time were observed. The pathologic diagnosis showed condensation, fusion and necrosis of villi. In the PBF in which a intrauterine fetal death (IUFD) was caused by placental factors, a sudden change in the PBF was observed showing the presence of an ischemia. In the PBF of pregnancy with diabetes, a large wave pattern change was observed indicating a decrease in the PBF. The pathologic diagnosis showed the fusion, hyalinization and necrosis of villi. The PBF wave patterns were classified into four kinds: normal pattern, angio-spasm pattern, delayed build-up pattern, circulation pattern. It has become clear that these abnormal wave patterns are frequently observed in toxemia of pregnancy, placental insufficiency and pregnancy with diabetes.