<i>APOE</i> polymorphism status (E4) may help in predicting the risk of recurrent implantation failure

To examine the association between apolipoprotein E (APOE) gene polymorphisms and incidence of recurrent implantation failure (RIF).In a case-control study, 100 women with RIF were compared with 100 women with at least one live child. DNA was extracted from the peripheral blood and APOE genotyping was performed through polymerase chain reaction, followed by restriction fragment length polymorphism. Statistical analysis was performed using Pearson's χ2 test.Our data revealed a significantly higher frequency for the E3/E4 genotype and E4 allele in the RIF group compared with controls. Significant differences in frequencies of the E4 allele (odds ratio [OR] 2.176; 95% confidence interval [CI] 1.131-4.185; P = 0.026) and E3/E4 genotype (OR 2.203; 95% CI 1.092-4.443; P = 0.038) were observed between the groups.The E4 polymorphism is correlated with RIF occurrence in women undergoing assisted reproductive treatment and potentially can be considered as a risk factor to the human implantation process.