Association of hereditary thrombophilia with intrauterine growth restriction

Background: Intrauterine growth retardation (IUGR) contributes significantly to fetal morbidity and mortality, but its etiology is unknown in most cases. Objective: The aim of this study was to examine the association between inherited thrombophilia and IUGR. Materials and Methods: A case-control study was performed in a tertiary referral center (Afzalipour Hospital) over 2-years period (2010-2011). Cases (n=25) were women who had pregnancies complicated by IUDR and control subjects (n=25) were women who had normal growth fetuses. All women were tested for inherited thrombophilia at least 4 weeks after delivery. Main outcome measure was prevalence of maternal thrombophlia. Genotyping for factor V Leiden, prothrombin gene (nucleotide G20210A), and MTHFR (C677T) mutation was performed by PCR technique. Protein C, S and antithrombin III activity were determined with a clotting assay (STA-Staclot, France). Results: The prevalence of hereditary thrombophilia was 68% (n=17) in IUGR group, and 32% (n=8) in control group (OR: 1.5, p=0.011, 95% CI: 1.3-14.8). The frequency of MTHFR (C677T) gene mutation (p=0.037; OR: 3.69) and protein S deficiency (p=0.034; OR: 5.41) was significantly increased in the group with IUGR compared with the control group. There was no significant difference between the two groups in prothrombin G20210A mutation (p=0.490) and protein C deficiency (p=0.609). A significant difference in the frequency of multiple thrombophilias was detected between the two groups (p=0.009). Conclusion: This study revealed that protein S deficiency and MTHFR gene mutation are more prevalent in pregnancies with IUGR.