Fibrinogen fractions in the third trimester of pregnancy and in puerperium

The concentration of fibrinogen, its fractions, and the concentration of C- reactive protein were determined in 45 healthy pregnant women before and af ter vaginal (27) or caesarean section (18) delivery. The control group cons isted of 33 blood donors. In pregnancy, increased concentration of total fi brinogen and its fractions and a normal concentration of C-reactive protein were noted. Three days after vaginal delivery the concentration of total a nd high molecular weight fibrinogen fraction decreased slightly and the rat io of high to low molecular weight fibrinogen increased. After caesarean se ction both total and high molecular weight fibrinogen and the ratio of high to low molecular weight fibrinogen increased. The C-reactive protein conce ntration increased after either type of delivery. The degree of augmentatio n, however, was ten times as strong after caesarean section. In all women a t the end of puerperium the concentrations of the compounds studied returne d to normal values, The results suggest that the mechanisms leading to the increase of fibrinogen during pregnancy and after delivery are different. T he increase of all fibrinogen fractions in pregnancy may depend first of al l on hormones, whereas the increased proportion of high molecular weight to low molecular weight fibrinogen after delivery depends on the acute phase reaction. The degree of this reaction depends on the type of delivery. (C) 2000 Elsevier Science Ltd. All rights reserved.