Adrenomedullin levels in normal and preeclamptic pregnancies at term

OBJECTIVE: Adrenomedullin (ADM) is a potent, hypotensive and nalrinretic peptide. Elevated levels are described in essential hypertension, renal disease, and congestive heart failure. We compare term maternal and fetal levels of ADM in normal and preeclamptic (PIH) pregnancies. STUDY DESIGN: Maternal plasma samples were obtained from 14 PIH and 1.5 normotensive primigravidas. 15 normotensive and 10 PIH patients had matched umbilical venous (UV) samples; 8 normal and 5 PIH patients had matched umbilical artery (l'A) samples. Radioimmunoassay for human ADM 1-52 (Phoenix pharmaceuticals) was used. Logistic regression, MannWhitney rank sum, and Friedman test were used. RESULTS: Maternal ADM was higher (p = 0.02) in preeclampsia. Term ADM >16 pg/ml gave optimal sensitivity (79%) and specificity (53%) for predicting PIH. Neither UA or UV were altered in PIH and they were highly correlated (R2 = 0.92 PIH, R2 = 0.82 control). However, the relationship between UA and UV ADM differed in PIH. In normal patients, UAADM was significantly higher than UV (p = 0.03) while in PIH UV ADM tended to be higher than UA (p = 0.18). Maternal and fetal levels did not correlate. Matrrnal UA UV mean -SE mean ±SE mean ±SE PIH (pg/ml) 42.3 ±10.5 27.9 ±7.9 40.2 ±9.1 Normal (pg/ml) 16.9 ±S.I 57.9 ±24.1 48.5 ±14.8 CONCLUSION: Maternal plasma ADM may prove diagnostically helpful in the future. The altered relationship of UA and UV ADM suggest ADM may be part of a compensatoiy response for both the fetus and the mother.