Prenatal development refers to the process in which a baby develops from a single cell into an embryo and later a foetus. The average length of time for prenatal development to complete is 38 weeks. During this time, a single-celled zygote develops into a full-term baby. The three primary stages of prenatal development are the germinal stage, the embryonic stage and the foetal stage.
Although 90-95 percent of babies born in the EU are considered healthy, abnormalities may arise during prenatal development. They are considered congenital (inherited or due to a genetic abnormality) or environmental (such as exposure to harmful substances). In other cases, problems may arise when a foetus is born too early.
The age, health status, nutritional status and the environment of the mother are closely connected with the health of a developing embryo. Extremes in any of these circumstances and conditions may result in developmental abnormalities. Chemical exposures are usually accidental, but links have been found between toxic environments and birth defects. However, usually we see such issues after the damage is done and we can still not avoid accidents that expose pregnant mothers to teratogenic or carcinogenic chemicals.