First trimester maternal serum placenta growth factor (PIGF) concentrations in pregnancies with fetal trisomy 21 or trisomy 18

Placenta growth factor (PIGF), an angiogenic factor belonging to the vascul ar endothelial growth factor family, pregnancy-associated plasma protein A (PAPP-A) and free fl-human chorionic gonadotrophin (beta -hCG) were measure d in maternal serum from 45 pregnancies with trisomy 21, 45 with trisomy 18 and 493 normal controls at 10-13 completed weeks of gestation. In the norm al pregnancies maternal serum PIGF levels increased exponentially with gest ation. The median multiple of the median (MoM) PIGF concentration in the tr isomy 21 group (1.26 MoM) was significantly higher (p <0.0001) than in the control group (1.00 MoM). In the trisomy 18 group the median PIGF was lower (0.889 MoM) but this did not quite reach significance (p = 0.064). The cor responding median MoM values for PAPP-A were 1.00 MOM for the controls, 0.4 9 MOM for trisomy 21 and 0.16 MoM for trisomy IS. The median MoM values for free beta -hCG were 1.00 MoM for the controls, 2.05 MoM for trisomy 21 and 0.38 MoM for trisomy 18. In the control group there was a small but signif icant correlation of PIGF with free beta -hCG (r = +0.1024) and PAPP-A (r = +0.2288). In the trisomy 18 group there was a significant association betw een PIGF and free beta -hCG (r = +0.2629) but not with PAPP-A (r = +0.0038) . In the trisomy 21 group there was a small but significant association wit h PAPP-A (r = +0.1028) but not with free beta -hCG (r = +0.0339). The separ ation of affected and unaffected pregnancies in maternal serum PIGF is smal l, and therefore it is unlikely that measurement of PIGF would improve scre ening for these abnormalities provided by the combination of fetal nuchal t ranslucency and maternal serum PAPP-A and free beta -hCG. Copyright (C) 200 1 John Wiley & Sons, Ltd.