Elevated endothelin levels are associated with increased placental resistance.

Abstract

The purpose of this study was to measure cord blood endothelin-1,2 concentrations in growth-restricted infants with abnormal flow velocity waveforms. Endothelin-1,2 concentrations were measured by radioimmunoassay in the cord blood of 16 growth-restricted infants with abnormal flow velocity waveforms before delivery, 16 growth-restricted infants with normal flow velocity waveforms before delivery, and 44 appropriately grown infants. Clinical data regarding pregnancy complications and neonatal outcome were collected. The mean endothelin-1,2 concentration in growth-restricted infants with abnormal flow velocity waveforms (50.2 +/- 16.4 pg/ml) was significantly higher than in growth-restricted infants with normal flow velocity waveforms (33.3 +/- 14.2 pg/ml, p < 0.05) or in appropriately grown infants (25.8 +/- 9.7 pg/ml, p < 0.05). Oligohydramnios was also associated with elevated endothelin levels. We conclude that endothelin-1,2 concentrations are elevated in growth-restricted infants with abnormal flow velocity waveforms and may play a role in the development of abnormal fetoplacental resistance.