Vascular endothelial growth factor and placenta growth concentrations in Down's syndrome and control pregnancies

Vascular endothelial growth factor (VEGF) and placenta growth factor (PLGF) are considered to play important roles in angiogenesis and vascular permea bility during placental development. Since trisomy 21 placentae show tropho blastic hypoplasia and hypovascularity, we investigated PLGF and VEGF synth esis in Down's syndrome pregnancies. Maternal serum was collected from 102 euploid and 24 trisomy 21 pregnancies between 15 and 20 weeks gestation and tested for these two factors by enzyme-linked immunosorbent assays. Protei n extracts from 15 normal and six trisomy 21 placentae were also tested. VE GF was not detected in maternal serum, while PLGF increased significantly w ith gestational age. Serum PLGF, transformed as a multiple of the gestation al age median (MoM), in Down's syndrome pregnancies was significantly lower than in euploid controls (mean 0.67 +/- 0.043 MoM versus 1.00 +/- 0.047 Mo M, analysis of variance F = 11.605, P < 0.001). Both VEGF and PLGF were det ected in placental protein extracts without variation according to gestatio nal age. Down's syndrome placentae had significantly less PLGF compared to normal placentae (Mann+Whitney, P < 0.05) but no difference was observed in placental VEGF content (Mann-Whitney, P = 0.94). Considering the biologica l properties of PLGF, this decrease may provide new insights into the mecha nism(s) leading to the structural and functional anomalies described in tri somy 21 placentae.