• natriuretic peptide;
  • newborn;
  • transition;
  • umbilical cord blood;
  • uroguanylin

Abstract Background: Uroguanylin is a novel natriuretic and diuretic peptide originally isolated from urine.

Methods: To determine whether uroguanylin has a physiologic role during the perinatal period, uroguanylin levels in umbilical cord plasma obtained at the time of delivery were measured by radioimmunoassay and compared with cord serum osmolality.

Results: Mean (±SD) cord plasma uroguanylin concentrations (8.8±2.1 fmol/mL) were higher compared with normal adult values. The extent of maturity, mode of delivery and gender did not appear to influence cord uroguanylin levels. The uroguanylin concentration had a significant positive correlation with cord serum osmolality.

Conclusion: These findings support some regulatory role of this peptide in perinatal renal and cardiovascular adaptation.