Background: FXIII Val34Leu (rs5985) and β-fibrinogen -455G/A (rs1800790) genotypes have been reported to be associated with recurrent spontaneous abortion (RSA). However, this topic is controversial. This study aimed to explore whether FXIII Val34Leu or β-fibrinogen -455G/A gene polymorphisms are related to RSA.
Methods: In this analysis, PubMed, HuGENet and Chinese National Knowledge Infrastructure (CNKI) databases were reviewed. Four models including the dominant model (Val/Val+Val/Leu vs. Leu/Leu), recessive model (Val/Val vs Val/Leu + Leu/Leu), co-dominant model (Val/Val vs. Val/Leu, Val/Val vs. Leu/Leu) and per-allele analysis (Val vs. Leu) were applied. The odds ratio (OR) with 95% confidence interval (CI) was used to assess the association between RSA and FXIII Val34Leu and β-fibrinogen -455G/A polymorphisms.
Results: Nine studies with 10 sets of data were included according to the inclusion criterion. A positive association was detected in the pooled results for the dominant model (Val/Val+Val/Leu vs. Leu/Leu; OR = 0.417, 95% CI: 0.180-0.965, I(2) = 45.60%) and co-dominant model (Val/Val vs. Val/Leu; OR = 0.638, 95% CI: 0.452-0.899, I(2) = 36.40%) for FXIII Val34Leu polymorphisms. However, no statistically significant association between β-fibrinogen -455G/A polymorphisms and RSA was detected in the four different models, including the Asian and Caucasian subgroup analyses.
Conclusions: Our meta-analysis demonstrates that the FXIII Val34Leu polymorphism has a close association with RSA and women who carry the Val allele for the FXIII Val34Leu polymorphism could have a protective effect against RSA. However, no association is detected between β-fibrinogen -455G/A polymorphisms and the risk of RSA. Future well-designed studies are needed to confirm these results.