Possible relationship between the ratio of Factor VIII complex and placental insufficiency in preeclampsia.

The ratios of Factor VIII-related antigen (FVIIIR:Ag) to Factor VIII clotting activity (FVIIIC) were measured in 50 women during normal pregnancy and in 20 patients with preeclampsia and with intrauterine fetal growth retardation (IUGR). The mean ratios of FVIIIR:Ag to FVIIIC ranged from 0.6 +/- 0.22 to 0.8 +/- 0.58 (mean +/- SD) from the 28th to 40th week of normal pregnancy. On the other hand, the mean ratios of FVIIIR:Ag to FVIIIC in patients with preeclampsia and IUGR were 1.40 +/- 0.69 and 1.59 +/- 0.78 (mean +/- SD), respectively. This finding suggests that FVIII complex ratio may be considered an index of endothelial damage in preeclampsia and IUGR. This ratio test could be a more sensitive and reliable indicator of placental insufficiency if applied with non-stress test during late pregnancy.