The behavior of amidolytic factor VII in smoking and non-smoking pregnant women in relation to their gestational age.

Abstract

Aim of the study was to assess the behavior of factor VII by commercial amidolytic assay in smoking and non-smoking pregnant women, and to compare this with the earlier reported factor VII:C levels during pregnancy and to discuss the role of F VII:Am with regard to thromboembolic complication in smoking pregnant women. Blood samples were obtained for 75 non-smoking pregnant women and 109 smoking pregnant women. For the chromogenic determination of F VII:Am a COA-Set F VII test kit from Kabi Vitrum was used. Correlations were calculated by the Spearman rank method. The Mann-Whitney-U test was used for the statistical comparison of the median values of the smoking and non-smoking groups. Both the smoking and non-smoking group displayed a significant increase of F VII:Am with gestational age (r=0.53; p<0.0001 for smokers and r=0.55; p=0.005 for non-smokers). The median concentration of F VII:Am was significantly higher in stage 3 (226%-211%) and stage 4 (262%-230%) in the smoking group. As elevated F VII:C levels have been described to be a risk factor for thrombotic events, the even higher than normally already enhanced plasma levels of FVII:Am in smoking pregnant women may indicate an additional risk for both thrombosis in the pregnant and for an increased fetal morbidity and even mortality caused by thrombotic processes in the uteroplacental vasculature. The results from the present study might be an extra argument to advise pregnant women not to smoke or to quit smoking during pregnancy.