Physiological distribution of placental growth factor and soluble Flt-1 in early pregnancy

Objective To examine the distribution of placental growth factor (PIGF), vascular endothelial growth factor (VEGF) and soluble VEGF receptor-1 (sFlt-1) in maternal and embryonic fluid compartments in early pregnancy. Method The concentrations of PlGF, VEGF and sFlt-1 were measured in coelomic fluid and maternal serum from 16 singleton pregnancies at 7.0-9.3 weeks. In six cases, amniotic fluid was also examined. Results The median concentration of PlGF was 14.1 (range 8.9-27.6) pg/mL in maternal serum, 13.9 (range 9.5-31.4) pg/mL in coelomic fluid and 8.9 (range 3.9-15.3) pg/mL in amniotic fluid. The concentration of PIGF increased between 7.0 and 9.3 weeks in maternal serum (p = 0.001) and decreased in coelomic and amniotic fluid (p = 0.001). The median concentration of sFlt-1 was 8561 (range 6724-10673) pg/mL in coelomic fluid, 523 (range 244-986) pg/mL in maternal serum, 30 (range 12-83) pg/mL in amniotic fluid (p = 0.0001), and it did not change significantly with gestation. VEGF was undetectable in most of the samples, and therefore, no further analysis was performed. Conclusion PlGF and sFlt-1 are present in the maternal and fetal fluid compartments in very early pregnancy, and their distribution is consistent with their site of production and the local conditions of transport. Copyright (C) 2008 John Wiley & Sons, Ltd.