High maternal and fetal plasma urocortin levels in pregnancies complicated by hypertension

OBJECTIVE We evaluated maternal and fetal plasma levels and placental mRNA expression of urocortin, a placental vasoactive neuropeptide, in singleton pregnancies (n = 70) complicated by hypertensive disorders classified as gestational hypertension (n = 36), pre-eclampsia (n = 19), and pre-eclampsia complicated by intrauterine growth restriction (PE/IUGR, n = 15), and in 70 healthy normotensive singleton pregnancies. METHODS Plasma levels were assayed by radioimmunoassay, fetal biometry by ultrasound scans, utero-placental and fetal perfusion by Doppler velocimetry, and placental urocortin mRNA expression by quantitative real time reverse transcriptase-polymerase chain reaction. The main outcome measures were the correlation of urocortin concentrations with patterns of the utero-placental and fetal circulation, and the early prediction of a poor neonatal outcome such as the occurrence of perinatal death and intraventricular hemorrhage. RESULTS Maternal and fetal urocortin levels were significantly (both P < 0.001) higher in gestational hypertension, pre-eclampsia and PE/IUGR women than in controls, and correlated with Doppler velocimetry patterns. Fetal concentrations were significantly (P < 0.0001) higher than and significantly (P < 0.0001) correlated to maternal levels. Placental mRNA expression did not change. Ten out of 140 newborns had a poor neonatal outcome, with an overall prevalence of 7.14% (pretest probability). Using the receiver operator characteristics curve analysis cut-off values, the probability of a poor neonatal outcome was 66.7% when urocortin was used, and was 0% if levels were unaltered. CONCLUSIONS Maternal and fetal urocortin levels are increased in hypertensive disorders of pregnancy. Since urocortin has vasoactive properties, the evidence of increased urocortin levels in hypertensive disorders may represent an adaptive fetal response.