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Teratogens are substances that may cause birth defects via a toxic effect on an embryo or foetus. Subcategories. This category has the following 13 subcategories, out ...
One example of this is the use of mammalian animal models to evaluate the molecular role of teratogens in the development of embryonic populations, such as the neural crest, [55] which can lead to the development of neurocristopathies. Genetically modified mice are commonly used for this purpose. In addition, pregnancy registries are large ...
Teratogens are classified in four main categories: Drugs in pregnancy – in addition to environmental chemicals, includes recreational drug use and pharmaceutical drugs. Vertically transmitted infections; Radiation, such as X-rays; Mechanical forces, such as oligohydramnios; Teratogens affect the fetus by various mechanism including:
Developmental toxicity is any developmental malformation that is caused by the toxicity of a chemical or pathogen. It is the structural or functional alteration, reversible or irreversible, which interferes with homeostasis, normal growth, differentiation, development or behavior.
Several factors affect the ability of a teratogen to contact a developing conceptus, such as the nature of the agent itself, route and degree of maternal exposure, rate of placental transfer and systemic absorption, and composition of the maternal and embryonic/fetal genotypes.
In some exposures, the chemical will be absorbed through the skin and will result in poisoning. [9] The eyes have a strong sensitivity to chemicals, and are consequently an area of high concern for chemical exposure. Chemical exposure to the eyes results in irritation and may result in burns and vision loss. [10]
Thalidomide is a known human teratogen and carries an extremely high risk of severe, life-threatening birth defects if administered or taken during pregnancy. [6] It causes skeletal deformities such as amelia (absence of legs and/or arms), absence of bones, and phocomelia (malformation of the limbs).
Tetracyclines are teratogens due to the likelihood of causing teeth discolouration in the fetus as they develop in infancy. For this same reason, tetracyclines are contraindicated for use in children under 8 years of age. Some adults also experience teeth discoloration (mild grey hue) after use.