title: Evaluation of smoking as a risk factor for activated protein C resistance during pregnancy.
abstract: OBJECTIVE
  The effect of smoking on the activated protein C (APC) ratio in normal gestation was systematically investigated. The frequency of acquired APC resistance (APCR) in the smoking and non-smoking subjects with normal follow-up of pregnancy and the outcome observed in these two groups were documented.
  
  
  METHODS
  A total of 180 normal pregnant women (non-smokers 138, smokers 42) in different trimesters of gestation admitted to the hospital were enrolled into a cross-sectional study. APC ratio, factor V, factor VIII, protein S and protein C were quantitated. Factor V Leiden mutation analyses were performed by real-time PCR.
  
  
  RESULTS
  This cross-sectional study tries to detail the effect of smoking on APCR together with the changes in some components of the protein C/protein S system which may contribute to alterations in the APC ratio in normal gestation. A decreased APC ratio observed in pregnancy was statistically significant in the smokers (p = 0.03). When the trimesters were taken into consideration, APC ratios were significantly lower in the third trimester in the smokers compared with the non-smokers in the same trimesters (p = 0.001). The difference in the APC ratio between the groups in early pregnancy was not significant.
  
  
  CONCLUSIONS
  These studies have demonstrated that the modified test abolishes the pregnancy-related effect on the APCRs in normal pregnant non-smoking women presumably by normalization of coagulation factors (except factor V). Our result for the non-smoking group is consistent with data provided in previous studies. However, we noted a very significant decrease in the APC ratio in smoking pregnant women in the third trimester, most likely secondary to decreased factor V levels.
authors.affiliation: Department of Obstetrics and Gynecology, Adnan Menderes, University School of Medicine, Aydin, Turkey. skafkas@adu.edu.tr
authors.forename: Samet
authors.initials: S
authors.lastname: Kafkas
authors.forename: Uzeyir
authors.initials: U
authors.lastname: Kalkan
authors.forename: Zahit
authors.initials: Z
authors.lastname: Bolaman
authors.forename: Muzaffer
authors.initials: M
authors.lastname: Sanci
authors.forename: Hasan
authors.initials: H
authors.lastname: Yüksel
authors.forename: Ali Riza
authors.initials: AR
authors.lastname: Odabaşi
mesh_terms: D020016:Activated Protein C Resistance / Q000097:blood / Q000453:epidemiology* / Q000209:etiology* / Q000235:genetics; D000328:Adult; D003430:Cross-Sectional Studies; D005165:Factor V / Q000032:analysis / Q000235:genetics*; D005169:Factor VIII / Q000032:analysis; D005260:Female; D006801:Humans; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011256:Pregnancy Outcome; D011264:Pregnancy Trimesters / Q000097:blood; D011486:Protein C / Q000032:analysis; D017293:Protein S / Q000032:analysis; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*
chemical_list: D011486:Protein C; D017293:Protein S; C095381:factor V Leiden; D005165:Factor V; D005169:Factor VIII