ACTIVATED PROTEIN-C SENSITIVITY, PROTEIN-C, PROTEIN-S AND COAGULATIONIN NORMAL-PREGNANCY

A prospective study of activated protein C sensitivity, protein C, pro tein S, and other coagulation factors in 239 women during normal pregn ancy was carried out. Protein C activity appeared unaffected by gestat ion, although an elevation of protein C activity was observed in the e arly puerperium. A fall in total and free protein S with increasing ge station was observed. Activated protein C sensitivity ratio (APC:SR) s howed a progressive fall through pregnancy. This fall correlated with changes in factor VIIIc, factor Vc and protein S. 38% of subjects, wit h no evidence of Factor V Leiden or anticardiolipin antibodies, showed a low APC:SR (APC:SR <2.6) in the third trimester of pregnancy. Aside from a significant reduction in birth weight, no difference in pregna ncy outcome was observed between these subjects and those with a norma l APC:SR. Activated protein C sensitivity ratio, modified by pre-dilut ion of patient samples with factor V depleted plasma, showed no consis tent trend with gestation.