Prenatal Maternal Stress: A Legacy That Transcends Generations

This discovery, which combines studies in mice and epigenetic findings, opens the door to understanding how stress experiences can be transmitted through the family line.

What is the Role of the Placenta and Epigenetics? The placenta, far more than a simple nutritional organ, acts as a center for hormonal regulation in the uterus for the fetus. During pregnancy, maternal stress can alter the function of the placenta by modifying the expression of key enzymes, such as 11β-HSD2, which is responsible for protecting the fetus from the harmful effects of corticosteroids—hormones produced in response to maternal stress. These alterations, mediated by epigenetic changes—including the modification of DNA and regulation through microRNAs—can program the fetus to face higher risks of cardiovascular, metabolic, and neuropsychiatric diseases later in life.

Multigenerational Impact In the study by Stephanie King and collaborators, it was highlighted that the impact of prenatal stress accumulates over generations. In mice, researchers found that high levels of stress during critical periods of pregnancy affect germ cells, causing pronounced epigenetic changes in subsequent generations and generating a cumulative effect.This phenomenon, known as transgenerational epigenetic inheritance, means that the effects of stress are not limited to direct exposure but can even manifest in the fourth generation, which is the first group completely "unexposed" to the initial stress.

Consequences on Health and Behavior. Epigenetic alterations induced by prenatal stress can change cellular metabolism and modify the functions of vital organs. Additionally, they have been linked to changes in behavior, such as increased anxiety, depressive tendencies, risky behaviors, and even motor hyperactivity.These findings underscore the importance of identifying biomarkers in the placenta that can predict risks of neurodevelopmental problems, allowing for early interventions and preventive strategies.

A Call for Prevention and Research. This type of research highlights the repercussions of maternal stress, prompting a call for societal prevention efforts to support mothers during pregnancy. Improving the well-being of future mothers not only benefits individual health but could also break an intergenerational cycle of risk for chronic diseases and developmental disorders.This study not only expands our understanding of the influence of the prenatal environment but also offers an innovative perspective on how the legacy of stress can shape the health of future generations. It invites both society and the scientific community to reflect on the importance of caring for mental and physical health from the earliest stages of life.

Specialized Terms and Definitions:

• Epigenetics: A set of chemical modifications on DNA and its associated proteins that regulate gene expression without altering the genetic sequence.

• Corticosteroids: Hormones produced by the adrenal glands in response to stress, with roles in metabolism and the immune system.

• DNA (Deoxyribonucleic Acid): The molecule that contains the genetic information of living beings.

• MicroRNAs: Small RNA molecules that regulate gene expression by interfering with protein production.

• Germ Cells: Precursor cells of eggs and sperm, responsible for transmitting genetic information to future generations.

• Transgenerational Epigenetic Inheritance: The transmission of epigenetic changes from one generation to the next without altering the DNA sequence.

• Biomarkers: Biological indicators, such as specific proteins or genes, that can predict the presence or risk of a disease.

• Neurodevelopment: The process of formation and maturation of the nervous system from the prenatal stage to adulthood.