Association between transforming growth factor-beta 1 polymorphisms and risk of pre-eclampsia: a meta-analysis.

PURPOSE:Pre-eclampsia (PE) is a common pregnancy-specific disorder characterized by hypertension and proteinuria. Previous studies have generated conflicting results regarding the association of transforming growth factor-beta 1 (TGF-β1) gene polymorphisms (+869 T/C, -509 C/T, +915 G/C, and -800 G/A) with PE risk. Therefore, we conducted this meta-analysis to more precisely assess the role of TGF-β1 gene polymorphisms in PE. METHODS:Eligible studies were retrieved from PubMed, Embase, Web of Science, Elsevier Science Direct, and several Chinese databases. The pooled odds ratios (ORs) and 95% confidence intervals (CIs) were used to calculate the associations. RESULTS:A total of 11 eligible studies (1463 cases/1754 controls) were included in this meta-analysis. A statistically significant association was found between the TGF-β1 + 869 T/C polymorphism and PE risk in the Asian population and in subgroup analyses of the Hardy-Weinberg equilibrium (HWE) in controls and healthy pregnant controls. There was a statistically significant association between TGF-β1 - 509 C/T polymorphism and PE risk among Asian women, and in the subgroup analysis of healthy pregnant controls. No obvious association was observed under any genetic model for the TGF-β1 + 915 G/C and -800 G/A polymorphisms and PE risk, or between the TGF-β1 + 869 T/C and -509 C/T polymorphisms and severity of PE. CONCLUSIONS:The present study suggested that the TGF-β1 + 869 T/C and -509 C/T polymorphisms are associated with an increased risk of PE in the Asian population. Further case-controlled studies with larger sample sizes are needed to confirm our results.