APOE polymorphism status (E4) may help in predicting the risk of recurrent implantation failure.

Objective Recurrent implantation failure (RIF) is defined as failure to achieve implantation after at least three cycles of assisted reproductive treatments (ART) with minimum of four high-quality transferred embryos. Deviations in normal expression profile of endometrial tissue can lead to unsuccessful implantation. Apolipoprotein E (APOE) gene up-regulation has been reported in the endometrium during the window of implantation. The present study aimed to examine the association between APOE polymorphisms and incidence of RIF. Methods In a case-control study, 100 RIF patients were compared to 100 women with at least one live child. DNA was extracted from the peripheral blood and APOE genotyping was performed through PCR, followed by RFLP method. Statistical analysis was done by Pearson chi-square test. Results Our data revealed a significantly higher frequency for the E3/E4 genotype and E4 allele in the RIF group compared to controls. Significant differences in frequencies of the E4 allele (P=0.026; OR=2.176; 95% CI: 1.131 to 4.185) and E3/E4 genotype (P=0.038; OR=2.203; 95% CI: 1.092 to 4.443) were observed between the groups. Conclusion The E4 polymorphism is correlated with RIF occurrence in ART patients and potentially can be considered as a risk factor to the human implantation process.