MATERNAL PLASMA ENDOTHELIN LEVELS AND FETAL STATUS IN NORMAL AND PREECLAMPTIC PREGNANCIES

Endothelin (ET) is a potent vasoconstrictor peptide. In this study, we investigated maternal venous plasma ET levels measured by Sandwich-en zyme immunoassay within a week before the onset of labor, and measured plasma renin activity and plasma aldosterone concentration by radioim munoassay in normal and severely preeclamptic pregnancies. Also, we de termined umbilical cord blood pH and gas concentrations after spontane ous vaginal deliveries and cesarean sections. There was a significant (p < 0.01) negative correlation between maternal ET levels within 1 we ek before the onset of labor and birth weights. There was no significa nt correlation between maternal ET levels and umbilical gas concentrat ions. These data suggest that the correlation is the result of decreas ing uteroplacental blood flow. We speculate that increased maternal ET expresses not only maternal renal vascular endothelial injury but als o other vascular endothelial injuries. These vascular injuries may occ ur at least 1 week before the clinical manifestation in the preeclampt ic mothers and their fetuses.