Introduction: The objective of this study was to determine whether the circulatory levels of endothelins, potent vasoconstrictor polypeptides produced mainly by endothelial cells, are increased in growth-retarded fetuses.
Study design: Fetal venous serum samples, withdrawn by ultrasound-guided cordocentesis from 11 growth-retarded fetuses and 10 normally-growing fetuses who underwent the procedure because of other unrelated indications, were examined for immunoreactive endothelin-1,2 by radioimmunoassay.
Results: Higher mean endothelin-1,2 levels were found in the sera of growth-retarded fetuses than in controls (16.8 +/- 4.2 versus 10.9 +/- 4.3 fmol/ml, p = 0.008). Within the growth-retarded group, there were no differences in endothelin-1,2 levels in the presence of either abnormal umbilical Doppler, asymmetry of growth-retardation, maternal signs of preeclampsia, or fetal acidosis.
Conclusion: High levels of endothelin-1,2 in the fetoplacental circulation may be pathophysiologically important in fetal growth retardation. However, the clinical significance of these elevated levels is yet to be determined.