Brain natriuretic peptide and endothelin-1 in the pathogenesis of polyhydramnios-oligohydramnios in monochorionic twins

Objective: We investigated the association between amniotic fluid levels of human brain natriuretic peptide, endothelin-1, and abnormal amniotic fluid volume in monochorionic twins with and without chronic twin-twin transfusion syndrome. Study Design: Amniotic fluid and fetal blood samples were obtained in utero or at cesarean delivery from monochorionic twins with (n = 20) or without chronic twin-twin transfusion syndrome (n = 10). Concentrations of atrial natriuretic peptide, human brain natriuretic peptide, and endothelin-1 (in picograms per milliliters) were determined by radioimmunoassay. Results: The amniotic fluid concentrations of human brain natriuretic peptide (P