Introduction
Early life programming refers to the process by which early exposure to a negative environment influences the outcome of a person's adulthood. Although epidemiological evidence supporting this has been known for decades, the processes underlying this process, specifically epigenetic modifications (modifications that regulate genes), have recently started to be understood. Pregnancy exposures, including maternal mental health, lifestyle choices, and possible teratogenic (disturb embryonic growth) and neurotoxic (neurologically destructive) exposures, greatly impact the developmental outcomes of the child.
Common mental illnesses in children and adolescents, such as hyperactivity, behavioral issues, and emotional disorders, are influenced by these factors. Thus, the focus of future efforts to prevent mental health problems should be on the prenatal stage, when prevention models should be created. Evidence-based therapies during the perinatal period may include general, more focused, and public health approaches. If such interventions are successful, the effects on (mental) health may be lifelong.
What Is Early Life Programming?
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Early life programming is the process by which environmental events impact fetal development and cause long-lasting changes to the composition and capabilities of biological systems.
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Programming is the term used to describe how a particular environmental element at a particular stage of development can have a lasting effect and possibly lead to a bias towards a particular response to future environmental inputs later.
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Early life programming starts before pregnancy as the majority of epigenetic modification imprints (like DNA methylation, histone modification, and microRNAs) included in the parent's DNA are removed during the production of both male and female primordial germ cells, though in certain cases, these imprints persist.
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However, the most active epigenetic imprinting of DNA happens during the developmental stage between conception and early childhood, resulting in changes to gene expression that have long-lasting consequences.
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Prenatal and postnatal nutrition are the most relevant environmental factors during fetal and infant development, and nutrition is one of the most significant.
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Additionally, the fetal phase is extremely adaptable and capable of responding to lifestyle and maternal environment, and nutrition is critical at this stage since it produces permanent DNA methylation.
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The food one eats, including vitamins, micronutrients, amino acids, fats, and carbohydrates, can impact how the genes function and are expressed in the uterus and early stages of life.
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This is done by influencing epigenetic mechanisms, which regulate the metabolism of folates in carbohydrates and transmethylation processes that affect DNA methylation, histones, and non-coding miRNAs.
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Scientists are studying this field of epigenetic research to determine if changes in gene expression caused by the mother's diet can make the offspring more prone to certain diseases like cardiovascular diseases, obesity, and diabetes.
What Are Various Types of Prenatal Exposure During Pregnancy?
Several factors can influence the quality of the prenatal environment. The first is an indirect pathway in which physiological responses to stress, such as endocrine, metabolic, or immunological responses, or poisons like nicotine or alcohol, produce vascular constriction, reducing oxygen and nutrient supply to the embryo. The second route directly transports maternal glucocorticoids or other chemicals through the placenta.
Three primary categories of prenatal exposure have been studied for various general health outcomes. They include maternal mental health, including prenatal stress, anxiety, and depression; teratogenic and neurotoxic encounters with specific toxins, including drug abuse, environmental toxins, and prescription medications; and lifestyle factors, like exercise and nutrition. Each type of exposure has also been studied, particularly regarding child and adolescent mental health outcomes, and these findings will be used to guide the review of such exposures.
How Changes in Pregnancy Affect the Developmental Outcome of the Fetus?
Fetal malnutrition affects the renal, cardiovascular, pulmonary, and endocrine systems and negatively impacts organ development and function, leading to low birth weight. On the other hand, excessive maternal nutrition induces macrosomia, which is linked to increased adiposity and a higher risk of juvenile obesity and cardiovascular disease.
Intrauterine hyperglycemia is linked to a higher risk of obesity and metabolic disorders in offspring. Moderate exercise activity is required to prevent potential metabolic disturbances in babies, and regular exercise practice can positively affect language offspring neurodevelopment. It is also a complementary tool for modulating the immune status of pregnant women and newborns.
What Is the Influence of Maternal Diet on Cognitive Development and Behavior?
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There are various key phases for brain development, ranging from the third trimester of pregnancy to the child's first two years of life. These times are marked by rapid maturation and brain development.
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The first trimester of pregnancy is associated with other crucial times that have also been identified as early organizational processes. These are extremely significant and involve cell migration, differentiation, neurogenesis, synaptic development, and the maturation of neurotransmission pathways.
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Adequate intake of calories, protein (which prevents embryonic losses, intrauterine growth restriction, and reduced postnatal growth), and certain minerals have been identified as having a special significance in these processes.
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These include iron, which is essential for rapid development and proliferation and plays a key role in brain development; zinc, which affects fetal growth; selenium, which reduces the risk of infant infection and improves psychomotor score; copper, which is needed for rapid growth and differentiation of cells for both the mother and fetus and iodine (which supports thyroid and neurological development).
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Thus, certain vitamins and other nutrients like folate (which promotes neural tube formation and cell proliferation), vitamin A (which supports brain growth and cell development), and choline (which affects stem cell proliferation and the structure and function of the brain and spinal cord), and long-chain fatty acids, (which are crucial for their roles as prostaglandin precursors and structural components of cell membranes) also play a crucial part in these processes.
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As a result, an inadequate diet that fails to give these essential nutrients in sufficient quantities during this key period can permanently change the offspring's brain functioning and behavior.
Conclusion
Early life programming has a significant impact on the course of human development. The mother's lifestyle, endocrine, metabolic, and nutritional status during pregnancy have a significant impact on the fetus's and offspring's growth and development, changing tissue function and potentially increasing the risk of developing several illnesses later in life. Nutrition in early life causes major physiological and metabolic changes, contributing to the risk of aging-related diseases.
