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| − | A '''birth defect''' is a structural, functional, or metabolic abnormality present at birth that results in physical or mental disability or death. There are more than 4,000 known birth defects, which may be caused by [[gene]]tic or [[environment]]al factors. In the US, About 150,000 babies are born each year with birth defects. | + | A '''birth defect''' is a structural, functional, or metabolic abnormality present at birth that results in physical or mental disability or death. There are more than 4,000 known birth defects, which may be caused by [[gene]]tic or [[environment]]al factors. In the US, about 150,000 babies are born each year with birth defects. |
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| | Some birth defects can be corrected by surgery after birth. Some examples are cleft palate, extra fingers or toes, webbed feet, club foot and 'hole in the heart'. | | Some birth defects can be corrected by surgery after birth. Some examples are cleft palate, extra fingers or toes, webbed feet, club foot and 'hole in the heart'. |
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| | Birth defects may be caused by nutritional deficiencies of the mother and can be avoided by ensuring a good diet with supplemental vitamins and minerals and also by avoiding [[alcohol]] and [[tobacco]]. [[Folic acid]] is a common supplement. | | Birth defects may be caused by nutritional deficiencies of the mother and can be avoided by ensuring a good diet with supplemental vitamins and minerals and also by avoiding [[alcohol]] and [[tobacco]]. [[Folic acid]] is a common supplement. |
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| − | There are potential birth defects that are genetic, and tests may be available to detect the condition in the womb or to test the parents and predict a potential risk if conception occurs. The parents can then assess the risk factors and decide to plan or avoid a pregnancy. | + | There are potential birth defects that are genetic, and tests may be available to detect the condition in the womb or to test the parents and predict a potential risk if conception occurs. The parents can then assess the risk factors and decide to plan or avoid a pregnancy. They may also choose to conceive a child using [[in vitro fertilization]] and pre-implantation genetic diagnosis, or if the child is already conceived, [[Abortion|end the pregnancy]]. |
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| − | In the 1960s many birth defects were also caused by the usage of Thalidomide, a hypnotic drug administered to mothers to ease their pain during birth.The usage of this drug caused various defects, the majority of cases being deformities of the arms and legs. | + | In the 1960s many birth defects were also caused by the usage of Thalidomide, a hypnotic drug administered to mothers to ease their pain during birth. The usage of this drug caused various defects, the majority of cases being deformities of the arms and legs. |
| − | == References == | + | |
| | + | == Testing == |
| | + | Two of the tests for birth defects in fetuses are chorionic villus sampling (CVS) and [[amniocentesis]]. CVS tests cells from the [[placenta]] and amniocentesis tests cells from the amniotic fluid. However, it is not well understood what happens to abnormal cells.<ref name="cambridge">"[https://www.cam.ac.uk/research/news/early-stage-embryos-with-abnormalities-may-still-develop-into-healthy-babies Early-stage embryos with abnormalities may still develop into healthy babies]". 29 March 2016. University of Cambridge. Accessed 13 May 2018.</ref> |
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| | + | A study published in 2016 found that in mice embryos where half the cells have an abnormal number of chromosomes, the abnormal cells are killed by [[apoptosis]] and the embryo continues to develop normally.<ref name="cambridge" /> |
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| | + | == References == |
| | + | {{reflist}} |
| | * http://kidshealth.org/parent/system/ill/birth_defects.html | | * http://kidshealth.org/parent/system/ill/birth_defects.html |
| − | McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc. | + | * McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc. |
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| | [[Category:Genetics]] | | [[Category:Genetics]] |