Paternal Age Effects on Reproductive Outcomes

Over the past decades, the average age of fathers at conception has risen substantially in many regions, driven by social, economic and demographic factors. While maternal age effects on fertility and offspring health are well established, growing evidence indicates that advanced paternal age (commonly defined as ≥40 years) also carries implications for sperm quality, reproductive success and child development. Age-related declines in semen volume, motility and morphology are accompanied by elevated rates of sperm DNA fragmentation and increased reactive oxygen species. Accumulation of de novo mutations, chromosomal aneuploidies and epigenetic alterations in ageing germ cells can impair fertilisation, embryo development and implantation. In assisted reproductive technologies (ART), advanced paternal age has been linked to reduced blastulation rates, lower numbers of high-quality embryos and modest decreases in clinical pregnancy rates. Beyond fertility, epidemiological data associate older fathers with heightened risks of neurodevelopmental and psychiatric disorders in offspring, including autism spectrum disorder and schizophrenia, as well as congenital anomalies. Mechanistic studies point to dysregulation of the sperm methylome and transcriptome, altered mitochondrial function and perturbations in early embryonic gene expression. Recognition of paternal age as a contributor to reproductive outcomes has practical implications for preconception counselling, ART practice and long-term child health surveillance.

Research from Nature Portfolio

No recent Nature Portfolio content available.

Paternal Age Effects on Reproductive Outcomes publication trend

The graph below shows the total number of articles in paternal age effects on reproductive outcomes across all publications each year (not limited to Nature Index journals).

Technical terms

Advanced paternal age (APA): Father’s age at conception, often defined as 40 years or older, associated with increased genetic and epigenetic risks to gametes and offspring.

DNA fragmentation index (DFI): A measure of sperm chromatin breaks; higher DFI indicates more fragmented DNA and reduced developmental competence.

Epigenetics: Heritable changes in gene expression not caused by alterations in DNA sequence, frequently mediated by DNA methylation and histone modifications.

Methylome: The complete set of DNA methylation marks across the genome, reflecting epigenetic regulation of gene activity.

Transcriptome: The full collection of RNA transcripts produced by the genome in a cell or tissue, indicative of gene expression profiles.

Inner cell mass (ICM): The cluster of cells within the blastocyst that gives rise to the embryo proper, sensitive to paternal epigenetic contributions.

Trophectoderm (TE): The outer cell layer of the blastocyst that forms placental tissues, generally more resilient to early epigenetic perturbations.

References

1. Paternal Age Amplifies Cryopreservation-Induced Stress in Human Spermatozoa. Cells (2024).
2. Paternal aging impacts expression and epigenetic markers as early as the first embryonic tissue lineage differentiation. Human Genomics (2024).
3. Identification of hub genes associated with decreased fertility in male mice of advanced paternal age. Frontiers in Cell and Developmental Biology (2025).
4. Sperm quality and paternal age: effect on blastocyst formation and pregnancy rates. Basic and Clinical Andrology (2017).