Genetic variants in the p53 pathway influence implantation and pregnancy maintenance in IVF treatments using donor oocytes.

Purpose: Single-nucleotide polymorphisms (SNPs) in the p53 pathways have shown to play a role in endometrial receptivity and implantation in infertile women undergoing in vitro fertilization (IVF). The present study aimed to assess the influence of these gene variants over pregnancy success through a receptivity model in recipients of egg donation treatments, when factors such as age and quality of the oocytes are standardized.

Methods: A nested case-control study was performed on 234 female patients undergoing their first fresh IVF treatment as recipients of donor oocytes. Genotyping of TP53 Arg72Pro (rs1042522), LIF (rs929271), MDM4 (rs1563828), and USP7 (rs1529916) SNPs in the recipients allowed comparison of allele and genotype frequencies and their association with the IVF treatment outcome.

Results: Grouped by genotypes, patients showed differences in IVF outcomes after the embryo transfer. Arg72Pro (rs1042522) gene variant was associated to changes in implantation and clinical pregnancy rates. The polymorphisms USP7 (rs1529916) and MDM4 (rs1563828) were associated to differential ongoing pregnancy rates and variable miscarriage events, respectively.

Conclusions: This study highlights the association between gene polymorphisms related to P53 function and their influence over IVF reproductive outcomes. Arg72Pro variant may influence early events, as lower implantation rates were found in homozygous for Pro72 allele. By contrast, MDM4 (rs1563828) and USP7 (rs1529916) gene variants were associated with the later maintenance of pregnancy.