Parental Age Effects on Offspring Health Outcomes

Recent demographic shifts have led to a global increase in the age at which individuals become parents, with growing evidence that both maternal and paternal age exert significant influences on offspring health across the life course. Advanced maternal age, often defined as 35 years or older at conception, has long been associated with obstetric complications, chromosomal anomalies and metabolic disorders in children. Parallel trends in paternal age reveal elevated risks of neurodevelopmental conditions in offspring, notably autism spectrum disorder and schizophrenia, as well as subtle impairments in cognitive function. These associations are underpinned by genetic mechanisms—including the accumulation of de novo mutations in the paternal germ line—and by epigenetic alterations in gametes and early embryos, such as age-dependent shifts in DNA methylation patterns. Animal models and human cohort studies have begun to unravel the role of the sperm and oocyte epigenomes, demonstrating that age-related changes in methylation at key genomic regions can influence embryonic gene regulation and subsequent phenotypes. Beyond biological pathways, psychosocial dimensions of delayed parenthood, such as family functioning and parental wellbeing, also shape developmental outcomes, emphasising the multifaceted nature of parental age effects. Recognising these risks, researchers and clinicians are exploring targeted interventions, from epigenetic restoration in pre-implantation embryos to public health strategies aimed at optimising reproductive timing and supporting older parents.

Research from Nature Portfolio

Quantitative analysis of parent–child trios has refined our understanding of paternal-age-related genetic risks, showing that each additional year of paternal age contributes modest increases in de novo single nucleotide variants, which in turn elevate offspring susceptibility to psychiatric and congenital disorders. Epidemiological data reveal that these mutational effects account for only a fraction of the observed associations, suggesting that non-genetic factors may also play a role. Complementary work in assisted reproduction settings has demonstrated that advanced paternal age is linked to alterations in sperm DNA methylation at thousands of CpG sites; these epigenetic changes correlate with reduced fertilisation rates, suboptimal embryo development and lower live-birth probabilities. High-dimensional mediation analyses identify specific genes whose methylation status mediates a substantial portion of the age effect on fertilisation, pointing to candidate biomarkers for reproductive counselling and potential targets for therapeutic intervention.

Parental Age Effects on Offspring Health Outcomes publication trend

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

Technical terms

Advanced parental age: Age threshold (commonly ≥35 years for mothers or ≥40 years for fathers) associated with increased biological and psychosocial risks to offspring.

De novo mutation: A genetic alteration present for the first time in one family member as a result of a variant in a germ cell of a parent or in the fertilised egg.

DNA methylation: An epigenetic modification involving the addition of a methyl group to cytosine bases, influencing gene expression without altering DNA sequence.

Epigenome: The complete set of epigenetic marks on the genetic material of a cell, encompassing DNA methylation, histone modifications and non-coding RNA interactions.

mTOR pathway: A conserved signalling network (mechanistic target of rapamycin) that regulates cell growth, metabolism and barrier integrity, with implications for the regulation of gamete epigenetics.

References

1. Building a family at advanced parental age: a systematic review on the risks and opportunities for parents and their offspring. Human Reproduction Open (2023).
2. Advanced paternal age effects in neurodevelopmental disorders—review of potential underlying mechanisms. Translational Psychiatry (2017).
3. Advanced Paternal Age Is Associated with Impaired Neurocognitive Outcomes during Infancy and Childhood. PLOS Medicine (2009).
4. Paternal-age-related de novo mutations and risk for five disorders. Nature Communications (2019).
5. Age-Associated Sperm DNA Methylation Alterations: Possible Implications in Offspring Disease Susceptibility. PLOS Genetics (2014).
6. Inhibition of aging-induced DNA hypermethylation by si-Dnmt3a/3b in pre-implantation embryos improves aberrant social behavior in offspring. International Journal of Biological Macromolecules (2025).
7. The psychosocial outcomes of older parenthood in early to mid-childhood: a mini-review. Human Reproduction (2023).
8. Sperm DNA methylation mediates the association of male age on reproductive outcomes among couples undergoing infertility treatment. Scientific Reports (2021).
9. Age‐related and species‐specific methylation changes in the protein‐coding marmoset sperm epigenome. Aging Cell (2024).
10. Mechanistic target of rapamycin (mTOR) pathway in Sertoli cells regulates age-dependent changes in sperm DNA methylation. eLife (2024).