Abstract
In a prospective study, blood from women in the 19th and 32nd week of pregnancy was analyzed for fibrin-ogen, prothrombin complex (P & P), F V, F VIII:C, F VIIIR:Ag, the VIIIR:Ag/VIII:C ratio, F IX, F XII, F XIII, antithrombin III, α2 -macroglobulin, aj-antitrypsin, α2-antiplasmin, the inhibitor of plasminogen activation and fi-brinogen degradation products. In normal pregnancies all the coagulation factors except F XIII were markedly increased, as were α1-antitrypsin and the inhibitor of plasminogen activation. Pregnancy did not influence the levels of antithrombin III, α2-macroglöbulin or α2-antiPlasmm- Pe-ripheral blood from women with growth retarded fetuses differed in that the levels of P & P, F XII (in the 19th week) and the inhibitor of plasminogen activation (in the 19th and 32nd weeks) were lower. The level of F XIII was higher in the 32nd week. A low grade activation of the coagulation system is suggested as one possible factor in the pathogene-sis of intrauterine growth retardation, which emphasized the value of heparin treatment in certain cases with this syndrome.