Objective: To assess soluble fms-like tyrosin kinase 1 (sFlt-1), free vascular endothelial growth factor (f-VEGF) and the f-VEGF/sFlt-1 quotient in twin pregnancies, and to determine if they are impaired in discordant twins.
Methods: Case-control study between 18 discordant and 46 concordant twin pregnancies. Angiogenic growth factors were measured in maternal serum during pregnancy and in umbilical artery and vein at birth.