Association between IL-10 gene polymorphisms and unexplained recurrent spontaneous abortion risk: a meta-analysis

Objective: The aim of this study was to evaluate the association of interleukin-10 (IL-10) polymorphisms (-1082A/G, -819C>T, -592C>A, IL-10 haplotypes) with unexplained recurrent spontaneous abortion (URSA) risk using meta-analysis. Methods: Eligible studies published until May 2016 were identified by searching electronic databases. The pooled odds ratios (ORs) and 95% confidence intervals (95% CI) were calculated. Results: Nineteen articles and 46 eligible studies involving 2765 cases and 2903 controls were considered in this study. The results indicated that the -1082A>G polymorphism was associated with URSA risk (allele model: OR = 1.21, 95% CI: 1.08-1.35; recessive model: OR = 1.52, 95% CI: 1.24-1.87; homozygous model: OR = 1.55, 95% CI: 1.23-1.97). Similar results were observed in both Asians and Caucasians. This study also revealed that the -819C>T polymorphism was associated with URSA risk (allele model: OR = 1.45, 95% CI: 1.07-1.95; dominant model: OR = 1.61, 95% CI: 1.05-2.47; recessive model: OR = 1.56, 95% CI: 1.08-2.26; homozygous model: OR = 1.94, 95% CI: 1.21-3.11; heterozygous model: OR = 1.54, 95% CI: 1.00-2.36). Subgroup analyses by ethnicity further identified this association in Asians but not in Caucasians. No correlation was observed between the -592C>A polymorphism and IL-10 haplotypes (GCC and ACC) and URSA risk. Conclusions: The IL-10 -1082A>G and -819C>T polymorphisms might increase URSA risk. In the subgroup analyses, the -819C>T polymorphism only increased the risk of URSA in Asians but not in Caucasians. The -592C>A polymorphism and IL-10 haplotypes might not be associated with URSA susceptibility.