Association between maternal tumor necrosis factor-α G308A polymorphism and interferon-γ A874T polymorphism and risk of preterm birth: a meta-analysis.

Objective(s): This article was undertaken to investigate the association between tumor necrosis factor-α (TNF-α) G308A polymorphism and interferon-γ (INF-γ) A874T polymorphism and risk of preterm birth (PTB) by performing a meta-analysis of available studies.

Study Design: Articles were chosen based on PubMed, EMBASE, Web of science, and China Biology Medicine (CBM) databases with no language restriction from their inceptions to 1 March, 2014. Specific inclusion criteria were used to evaluate articles. Meta-analysis was performed by using a random or fixed effect model with STATA 11.0 software. We estimated the summary odds ratios (ORs) with its corresponding 95% confidence interval (95%CI) to assess the association.

Results: 21 eligible case-control studies with a total of 2103 cases and 5070 controls were finally included into this meta-analysis. Pooled analysis showed that A allele of TNF-α G308A was not associated with increased PTB risk (OR=0.84, 95%CI: 0.65-1.07, p=0.167 for G vs. A). Stratifying analysis for ethnicity and different definition of PTB also indicated that A allele was not associated with increased PTB risk. However, the meta-analysis showed that INF-γ A874T polymorphism was associated with the increased risk of PTB (OR=1.14, 95%CI: 1.11-1.73, p=0.004 for A vs. T). Stratifying analysis was not performed due to the small sample size.

Conclusion(s): TNF-α G308A polymorphism was not associated with an increased risk of PTB, but INF-γ A874T polymorphism may contribute to increasing susceptibility to PTB. Detection of polymorphism of INF-γ A874T might be a promising biomarker for the diagnosis and prognosis of preterm delivery.