Plasma and amniotic fluid concentration of fibronectin during normal and diabetic pregnancy

Fibronectin is a plasma glycoprotein which is involved in coagulation, platelet function, tissue repair and the vascular endothelial basement membrane. To ascertain the influence of pregnancy on plasma concentrations of fibronectin, we qualified plasma concentrations of fibronectin in normal pregnant women during the first, second and third trimester; at the time of delivery; and on the third day post partum, using a radial immunodiffusion plate procedure. The concentrations of fibronectin found in these samples were compared with the concentration of fibronectin in 20 pregnancies complicated by diabetes. Mean plasma concentrations of fibronectin rose significantly through pregnancy and were significantly higher during delivery. A decrease in the concentrations was noticed on the third post partum day. An even more significant decrease of maternal plasma concentrations was noticed during cesarean section in normal pregnancies as compared to the concentrations found at the time of normal delivery. Of the diabetic group of women studied, higher concentrations of plasma fibronectin were found at the time of cesarean section than at the time of delivery. Maternal plasma concentrations of fibronectin were significantly greater than amniotic fluid and umbilical cord plasma concentrations.