Maternal Hypoxia and Its Epigenetic Imprint: Long-Term Implications on Immune System Ontogeny and Forensic Biomarker Identification in Offspring

Maternal hypoxia is a critical disruptor of fetal development, with enduring consequences for immune system ontogeny. This review examines the multifactorial impacts of intrauterine oxygen deprivation, emphasizing its role in impairing immune competence through disruptions in T and B cell differentiation, altered cytokine signaling, and long-lasting epigenetic reprogramming. The fetal immune system, highly sensitive to oxygen levels during gestation, is particularly vulnerable to these changes, which elevate lifelong susceptibility to infections, allergies, autoimmune diseases, and chronic inflammation. Hypoxia-inducible factors (HIFs) mediate many of these effects by interacting with epigenetic regulators such as DNA methylation, histone modifications, and non-coding RNAs that modulate gene expression without altering the DNA sequence. In addition to pathophysiological outcomes, the review highlights the forensic potential of hypoxia-induced epigenetic markers. These stable, exposure-sensitive modifications offer promising tools for reconstructing prenatal environments in post-mortem investigations, especially when traditional pathological indicators are absent. Technologies including bisulfite sequencing, pyrosequencing, and droplet digital PCR are evaluated for their utility in detecting these markers in degraded biological samples. This paper also addresses geographic and socioeconomic disparities that exacerbate hypoxia risks, particularly in high-altitude and low-resource settings, and underscores the importance of prenatal care, nutritional optimization, and early intervention. Based on a structured literature review of peer-reviewed studies from 2019 to 2024, this work integrates emerging evidence linking maternal hypoxia to immune dysfunction, developmental programming, and forensic science. It advocates for interdisciplinary research and public health strategies aimed at mitigating hypoxia-related risks and improving maternal-fetal outcomes across the lifespan.