What is Birth defect?
Congenital disorder, also known as congenital disease or birth defect, is a condition existing at or before birth regardless of cause. Of these diseases, those characterized by structural deformities are termed "congenital anomalies" and involve defects in a developing fetus. Birth defects vary widely in cause and symptoms. Any substance that causes birth defects is known as a teratogen. Some disorders can be detected before birth through prenatal diagnosis (screening).
Birth defects may be the result of genetic or environmental factors. This includes errors of morphogenesis, infection, epigenetic modifications on a parental germline, or a chromosomal abnormality. The outcome of the disorder will depend on complex interactions between the pre-natal deficit and the post-natal environment. However, the relationship between offspring health and paternal exposures, age, and lifestyle are still relatively weak. This is likely due to the fact that paternal exposures and their effects on the fetus are studied far less extensively than maternal exposures.
Birth defects are present in about 3% of newborns.