Clinical Significance of the Fetal PSP Test

Abstract

The authors studied a clinical value of the fetal PSP test reported in the previous paper. The low level in the fetal PSP test was defined to be below 15% in three-hour excretion rate. The low excretion of PSP was found in about onehalf of the postdate group and of the toxemia group. About 40% of cases with the low excretion rate of PSP showed the low urinary estriol level below 10mg/day by Kambegawa's method. Close relation was recognized between the low value of the PSP test and other several factors concerning the placental permeability; such as the low placental-fetal weight ratio below 0.15, the existence of calcification and white infarct in the placenta, and the histo-pathologic findings of the placenta. Intrauterine fetal distress and neonatal asphyxia were also found more frequently in the group of low PSP excretion than in the normal group. The authors believe that the fetal PSP test is a safe and valuable method in estimating the permeability funetion of the placenta of late pregnancy.
1. The authors devised a method to examine permeability function of the placenta by injection of PSP into the fetus. The normal excretion rate in maternal urine was defined to be more than 16% per three hours.
2. The coincidence rate between the fetal PSP test and the urinary estriol was about 42%.
3. Close relation was recognized among the result of the fetal PSP test, histologic findings of the placenta, such as calcification, infarct and other histologic findings, and placental-fetal weight ratio.
4. Intrauterine fetal distress in partu and neonatal asphyxia were found more frequently in the group of low PSP excretion.
5. Low PSP excretion below 15% per three hours was found in 57% of cases with prolonged pregnancy and in 52% of cases with toxemia of pregnancy.
6. The authors believe that the fetal PSP test is a simple and safe test for permeability function of the placenta.