The β-2-adrenergic receptor (ADRB2) gene has an important impact on smooth muscle relaxation, including the smooth muscles of the uterus. The results of previously published studies of the association between the ADRB2 rs1042713 polymorphism and spontaneous preterm birth (SPTB) were inconsistent. We evaluated the association between ADRB2 and SPTB in a case-control association study in a Slovenian sample population and performed a meta analysis of previously published studies. No association was found between the polymorphism in the ADRB2 gene and SPTB in the Slovenian sample of 98 SPTB patients and 135 controls under dominant [χ2 = 0.01, p = 0.92, odds ratio (OR) = 1.03, 95% confidence interval (95% CI) = 0.52-2.04), recessive (χ2 = 0.01, p = 0.92, OR = 0.98, 95% CI = 0.57-1.70) and codominant genetic models (χ2 = 0.01, p = 0.92, OR = 0.99, 95% CI = 0.59-1.68). The meta analysis of a pooled sample of 404 SPTB patients and 878 controls suggested no association of ADRB2 polymorphism and SPTB under dominant (OR = 1.12, 95% CI = 0.81-1.54) and recessive genetic models (OR = 0.84, 95% CI = 0.64-1.12). These findings suggest no association between the ADRB2 rs1042713 gene polymorphism and SPTB. Further association studies with larger sample sizes are needed.
