Differences in paternal and maternal contribution to embryo aneuploidy

Abstract

Introduction Advanced maternal age and male factor infertility have been related to the presence of aneuploidies in the embryos. The objective of this study was to evaluate the different effect of both factors in the chromosomal constitution of the trophectoderm biopsies of infertile couples performing Preimplantation Genetic testing for aneuploidy (PGT-A). Material and methods this is a retrospective observational study in trophectoderm biopsies performed from January 2013 to March 2018 using CGH array and Next Generation Sequencing (NGS) technologies for PGT-A. A total of 1,187 trophectoderm day 5/6 biopsies were analyzed in three groups: Group 1 of isolated advanced maternal age (≥38 years; normozoospermia) including 550 biopsies from 176 PGT-A cycles; Group 2 of isolated increase of aneuploid sperm (female age For CGH array, amplified DNA and reference DNA were labeled and co-hybridized in 24sure arrays. After washing, slides were scanned and analyzed by BlueFuse Multi software (Illumina, Inc.). For NGS, Ion ReproSeq PGS kit was used to amplify the DNA and barcoding the samples. PGM or Ion Chef and Ion S5 System instruments were used. Data analysis was done using Ion Reporter software (Thermo Fisher Scientific, USA). Chromosome aneuploidies (monosomies, trisomies) and partial duplication/deletion (dup/del) with a size >15 Mb were determined for the 24 chromosomes. Fisher's exact test and Welch's t-test with Bonferroni correction were used for statistical comparisons. Results at embryo level, group 1 showed the higher incidence of aneuploid embryos (61.8%), being similar to the observed in group 3 (59.9%) and significantly increased when compared to group 2 (43.0%, p Conclusion Advance maternal age is the main factor associated to the presence of aneuploidies in embryos, increasing the risk of aneuploidies meanly for acrocentric chromosomes. However, male factor infertility associated to abnormal FISH in sperm increases the incidence of partial dup/del and gonosome trisomies in the embryos, being this risk even higher when maternal age is also associated.