Metformin decreases the aneuploidy rate in the human preimplantation embryos of the patients with polycystic ovarian syndrome

Background Diploid-aneuploid mosaicism is prevalent in preimplantation stage while transfer of such embryos in case of having enough normal cells could lead to live birth. The results of Chromosomal analysis of blastocyst cultured in diabetic conditions represents that these conditions could lead to increase the number of aneuploid cells. Metformin is a drug that widely prescribed for type 2 diabetes (T2D) and polycystic ovarian syndrome (PCOS). Purpose of this study was evaluation the effect of metformin on aneuploidy rate of preimplantation human embryos. Methods We randomly included spare embryos of infertile couples with histories of PCOS and male infertility in two groups: treatment with metformin (exposed) and untreated (control). In the exposed group, we treated day-2 human embryos with non-toxic concentration of metformin for 24 hours. On the fifth day post-fertilization, we morphologically assessed the developmental progression of the embryos and evaluated the rate of aneuploidy by using Fluorescent In Situ Hybridization (FISH). Results Five micromolar was selected as non-toxic dose of metformin. By assessment of 770 human embryos, there was no difference between exposed and control groups in the development, certainly the rate of blastocyst formation (p=0.692). According to FISH analysis for 60 blastocysts, diploid-aneuploid mosaicism was the most frequent chromosomal status. The percentage of euploid cells in the embryos of the patients with PCOS in the exposed group was higher than those of control group (p= 0.046) whilst for the embryos of the patients with male infertility history, there was no significant difference between exposed and control groups. Conclusion Our results showed that aneuploidy rate following exposure of human preimplantation embryos with metformin in the PCOS patients was decreased therefore metformin might be benefit for this group of the infertile patients through decrease of aneuploid cells without negative effect on developmental potential.