Abstract
The objective of the present study was to investigate the association between recurrent implantation failure (RIF) and vascular endothelial growth factor (VEGF) gene polymorphisms that are associated with various female infertility disorders. A total of 116 women diagnosed with RIF and 218 control subjects were genotyped for the VEGF -2578C>A, -1154G>A, -634C>G and 936C>T polymorphisms using a polymerase chain reaction-restriction fragment length polymorphism assay. The VEGF -2578AA genotype was associated with an increased prevalence (≥4) of RIF [adjusted odds ratio (AOR)=2.77; 95% confidence interval (CI)=1.10-7.02; P=0.031], whereas the VEGF -634CG+GG genotype was associated with an increased incidence of total RIF (AOR=2.03; 95% CI=1.02-4.05; P=0.044) and ≥4 RIF (AOR=3.16; 95% CI=1.19-8.37; P=0.021). The results of the haplotype analysis indicated that -2578A/-1154A/-634G/936C (AOR=1.76; 95% CI=1.03-3.00; P=0.040 for total RIF and AOR=2.11; 95% CI=1.12-3.97; P=0.021 for ≥4 RIF) was associated with the occurrence of RIF. In addition, it was revealed that there was a significant difference in serum prolactin level associated with the VEGF -634C>G polymorphism (P=0.013). Therefore the findings of the present study indicate that the VEGF -2578AA genotype, -634G allele and -2578A/-1154A/-634G/936C haplotype may be genetic markers for susceptibility to RIF. However, further studies on VEGF promoter polymorphisms that include an independent randomized-controlled population are required to confirm these results.