Sperm DNA methylation mediates the association of male age on reproductive outcomes among couples undergoing infertility treatment

Oladele A Oluwayiose,Alexander Suvorov,Hachem Saddiki,Laura B Balzer,J Richard Pilsner,Chelsea Marcho,Nicole Brandon,Brian W Whitcomb,Rahil Tayyab,Haotian Wu,Lisa Hill,Cynthia K Sites

doi:10.1038/s41598-020-80857-2

Abstract

Parental age at time of offspring conception is increasing in developed countries. Advanced male age is associated with decreased reproductive success and increased risk of adverse neurodevelopmental outcomes in offspring. Mechanisms for these male age effects remain unclear, but changes in sperm DNA methylation over time is one potential explanation. We assessed genome-wide methylation of sperm DNA from 47 semen samples collected from male participants of couples seeking infertility treatment. We report that higher male age was associated with lower likelihood of fertilization and live birth, and poor embryo development (p < 0.05). Furthermore, our multivariable linear models showed male age was associated with alterations in sperm methylation at 1698 CpGs and 1146 regions (q < 0.05), which were associated with > 750 genes enriched in embryonic development, behavior and neurodevelopment among others. High dimensional mediation analyses identified four genes (DEFB126, TPI1P3, PLCH2 and DLGAP2) with age-related sperm differential methylation that accounted for 64% (95% CI 0.42–0.86%; p < 0.05) of the effect of male age on lower fertilization rate. Our findings from this modest IVF population provide evidence for sperm methylation as a mechanism of age-induced poor reproductive outcomes and identifies possible candidate genes for mediating these effects.

Highlights

IntroductionAdvanced male age is associated with decreased reproductive success and increased risk of adverse neurodevelopmental outcomes in offspring
Parental age at time of offspring conception is increasing in developed countries
Outcomes of assisted reproductive technology (ART) treatment considered in these analyses include fertilization of retrieved oocytes; high quality embryo status at multiple time points; and whether the treatment resulted in a live birth

Summary

Introduction

Advanced male age is associated with decreased reproductive success and increased risk of adverse neurodevelopmental outcomes in offspring Mechanisms for these male age effects remain unclear, but changes in sperm DNA methylation over time is one potential explanation. Research in clinical populations of couples seeking treatment for infertility allows direct observation of reproductive events including fertilization, embryo development, and pregnancy outcomes. Such observations are largely occult among the general population. The objective of this study was to examine the role of sperm DNA methylation as a potential mechanism by which male age affects assisted reproductive technology (ART) outcomes among couples seeking infertility treatment (Fig. 1A)

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