Angiogenesis, a critical process for growth and development is altered in intrauterine growth restriction (IUGR). Vascular endothelial growth factor (VEGF) and its receptors VEGFR-1, soluble (s) VEGFR-1 and VEGFR-2 represent a regulatory system, essential for both physiological and pathological angiogenesis.To study the implication of sVEGFR-1-a VEGF antagonist-in IUGR.Prospective study.Twenty-five IUGR and 15 appropriate for gestational age (AGA) full-term fetuses and neonates with their mothers were included in the study.sVEGFR-1 levels were determined by enzyme immunoassay in the serum of: mothers (MS), umbilical cords (UC)-representing fetal state - and neonates on day 1 (N1) and 4 (N4) of life.MS, UC, N1 and N4 sVEGFR-1 levels in IUGR were significantly higher compared to respective AGA cases (p = 0.005, p = 0.026, p = 0.005 and p = 0.017, respectively). In IUGR and AGA groups, maternal sVEGFR-1 levels were significantly higher than fetal and neonatal levels (p in all cases < 0.001). The latter presented in both IUGR and AGA groups a significant decrease from UC to N4 (p in all cases < 0.01). MS, N1 and N4 sVEGFR-1 levels negatively correlated with the infants' customized centiles [(r = -0.489, p = 0.001), (r = -0.440, p = 0.004), (r = -0.431, p = 0.006), respectively].Higher sVEGFR-1 levels in the IUGR as compared to the AGA group possibly reflect the predominance of antiangiogenic mechanisms present in IUGR. The decrease of sVEGFR-1 levels from UC to N4 may represent ex utero initiation of growth and development and therefore, prevalence of angiogenic mechanisms.