Not Just Genes: Epigenetics and IVF Ethics

Authored by: Skye Romo

Art by: Vanessa Chen Hsieh

In early 2024, the Alabama Supreme Court declared that frozen embryos are legally children, a ruling that caused several fertility clinics to halt in vitro fertilization (IVF) procedures almost overnight (NPR, 2024). Appointments were canceled, doctors feared lawsuits or even criminal charges, and national headlines erupted. While the legal debate over when life begins has captured the public's attention, a quieter scientific shift has been reshaping reproductive health technology, policy, and decision-making for decades: the rise of epigenetics, a field that challenges what we long believed about inheritance and biological identity.

Epigenetics, at its core, is the study of how gene expression can change without altering the DNA sequence itself. Environmental factors such as diet, trauma, socioeconomic stress, and chemical exposures can lead to the creation of various biochemical markers, such as DNA methylation and histone modifications, that influence which genes are turned on or off (Feil & Fraga, 2012; Berger et al., 2009). Rather than rewriting the genetic code, these “marks” shape how that code is read and can be passed down to future generations (Haig, 2004).

Although the term epigenetics was coined in 1942 by developmental biologist Conrad Waddington, it wasn't until the early 2000s that the field gained serious traction in biomedical research (Haig, 2004). One of the most cited studies comes from Yehuda et al. (2016), who found that the children of Holocaust survivors showed altered patterns of stress-response genes, suggesting that trauma may be heritable both psychologically and biologically. Similarly, studies of the Dutch famine of 1944 found that children and grandchildren of malnourished mothers were more likely to have lower birth weights and higher risks of metabolic disease, despite receiving normal nutrition themselves (Lumey, Stein, & Susser, 2011).

These early findings helped scientists understand inheritance as a dynamic system involving genetic code and lived experience, laying the groundwork for today's questions about how rapidly advancing reproductive technologies might interact with the epigenome. A recent systematic review by Vörös et al. (2024) found altered DNA methylation patterns in embryos conceived via IVF, particularly in genes related to growth, immune function, and neurological development. In addition, cryopreservation, or the freezing of embryos, has been associated with changes in gene expression that may affect long-term health outcomes (Palomares & Rodriguez-Wallberg, 2022). While these shifts are not necessarily harmful, they suggest that IVF may interact with the developing epigenome in subtle but lasting ways.

Environmental exposures have also become relevant to the conversation. A study by Schuller et al. (2021) found that simulated wildfire smoke significantly altered sperm DNA methylation in mice, potentially affecting fertility and offspring development. On the paternal side, oxidative stress in sperm has been linked to epigenetic dysregulation that could influence both male fertility and the health of future generations (Kaltsas et al., 2024). These findings complicate the narrative of personal responsibility in reproduction, suggesting that stress, inequality, and environmental degradation can imprint themselves biologically and be passed down. New discoveries raise fundamental questions about how society defines reproductive responsibility. If environmental stress, trauma, and inequality can literally write themselves onto our biological inheritance, what obligations do we have, not just as individuals, but as communities, to reduce harm? And how will policies adjust with data that shows we inherit more than just DNA?

Scholars have also warned that epigenetics could be misused to reinforce discrimination. Meloni and Müller (2018) argue that certain interpretations of epigenetic science risk biologizing inequality by framing marginalized groups as biologically “damaged”. While the field offers profound possibilities for understanding health, it also carries the risk of reviving old eugenic ideologies under the guise of scientific language.

However, the field also offers hope and new possibilities for the future. While many epigenetic marks are stable, they are not necessarily permanent. Studies have suggested that interventions such as improved nutrition and reduced environmental stress could partially reverse some forms of epigenetic dysregulation (Feil & Fraga, 2012). This opens the door to new approaches in preventative care that aim not just to treat disease, but to promote multi-generational well-being.

As debates over IVF, personhood, and reproductive rights intensify, one thing becomes increasingly clear: our understanding of inheritance must evolve. We are not merely genetic beings, but rather we are shaped by the environments we live in and the experiences of those who came before us. Epigenetics helps us to look beyond genes and toward overall context. In doing so, it offers a framework not just for understanding health, but for building a more ethical and future-focused reproductive landscape.

References:

1. NPR. (2024, February 20). Alabama Supreme Court rules frozen embryos are 'children' under state law. NPR. https://www.npr.org/2024/02/20/1232815486/alabama-supreme-court-frozen-embryos 

2. Johns Hopkins Bloomberg School of Public Health. (2024). The Alabama Supreme Court’s ruling on frozen embryos. https://publichealth.jhu.edu/2024/the-alabama-supreme-courts-ruling-on-frozen-embryos 

3. Berger, S. L., Kouzarides, T., Shiekhattar, R., & Shilatifard, A. (2009). An operational definition of epigenetics. Genes & Development, 23(7), 781–783. https://genesdev.cshlp.org/content/23/7/781 

4. Feil, R., & Fraga, M. F. (2012). Epigenetics and the environment: Emerging patterns and implications. Nature Reviews Genetics, 13, 97–109. https://www.nature.com/articles/nrg3142 

5. Haig, D. (2004). The (Dual) origin of epigenetics. Cold Spring Harbor Symposia on Quantitative Biology, 69, 67–70. https://symposium.cshlp.org/content/69/67

6. Yehuda, R., Daskalakis, N. P., Lehrner, A., et al. (2016). Influences of maternal and paternal PTSD on epigenetic regulation of the glucocorticoid receptor gene in Holocaust survivor offspring. American Journal of Psychiatry, 173(8), 856–864. https://pubmed.ncbi.nlm.nih.gov/24832930/ 

7. Lumey, L. H., Stein, A. D., & Susser, E. (2011). Prenatal famine and adult health. Annual Review of Public Health, 32, 237–262. https://pubmed.ncbi.nlm.nih.gov/21219171/ 

8. Vörös, C., Varthaliti, A., Mavrogianni, D., et al. (2024). Epigenetic alterations in ovarian function and their impact on assisted reproductive technologies: A systematic review. Biomedicines, 13(3), Article 730. https://pubmed.ncbi.nlm.nih.gov/40149706/ 

9. Palomares, A. R., & Rodriguez-Wallberg, K. A. (2022). Update on the epigenomic implication of embryo cryopreservation methods applied in assisted reproductive technologies with potential long-term health effects. Frontiers in Cell and Developmental Biology, 10, Article 830722. https://pmc.ncbi.nlm.nih.gov/articles/PMC9096028/ 

10. Schuller, A., Bellini, C., Jenkins, T. G., et al. (2021). Simulated wildfire smoke significantly alters sperm DNA methylation patterns in a murine model. Environmental Epigenetics, 7(2). https://pmc.ncbi.nlm.nih.gov/articles/PMC8473101/ 

11. Kaltsas, A., Markou, E., Kyrgiafini, M. A., et al. (2024). Oxidative-stress-mediated epigenetic dysregulation in spermatogenesis: Implications for male infertility and offspring health. Environmental Epigenetics, 10(1). https://pmc.ncbi.nlm.nih.gov/articles/PMC11765119/ 

12. Meloni, M., & Müller, R. (2018). Transgenerational epigenetic inheritance and social responsibility: Perspectives from the social sciences. Environmental Epigenetics, 4(2). https://pmc.ncbi.nlm.nih.gov/articles/PMC6070063/