Problem: A high proportion of recurrent spontaneous abortions (RSA) remains unexplained. Cytokine genotyping has been investigated. We studied the relationship between unexplained RSA, IL6 (−174 G→C) and TGFB1 (+869, T→C; +915, G→C) gene polymorphisms.
Method of Study: The case–control study composed of 57 south Brazilian women, with unexplained RSA and 74 controls carefully matched was performed. Cytokine genotyping was performed by the polymerase chain reaction–sequence specific primer method, using the ‘Cytokine Genotyping Tray’.
Results: The results showed that the genotypic frequencies did not differ from samples for TGFB1 gene. In relation to IL6 gene polymorphism there was a statistical difference in genotypic distribution between samples (P ≤ 0.025). The frequency of the C/C genotype was increased in women with RSA in comparison with the frequency observed in controls: 18% versus 4% (P = 0.01).
Conclusions: This result strengthened the importance of IL6 genotypes in the pathogenesis of RSA of unknown cause in the south Brazilian population.