Amniocentesis is a medical procedure sometimes performed during pregnancy to help determine the health and maturity of an unborn baby. It involves the withdrawal and study of a small amount of the amniotic fluid that surrounds the foetus in the mother's uterus. Laboratory tests on the fluid, which contains cells shed by the foetus, enable detection of many serious disorders that may affect the foetus. Such disorders include Down's syndrome and spina bifida. Amniocentesis involves little risk to either the mother or the foetus.
Amniocentesis is mostly performed around the 16th week of pregnancy on 'at risk' mothers. These include those more than 35 years of age and those with genetic disorders in the family. If tests reveal serious abnormality, likely to cause death or pronounced handicap, the parents may choose to end the pregnancy. Otherwise, doctors can plan ahead for early treatment, either in the womb or at birth. If there is some medical reason for delivering a baby before it is due to be born, amniocentesis may be performed later in pregnancy. In this case, tests show whether the baby is likely to survive outside the womb. An obstetrician performs amniocentesis with the aid of ultrasound which enables the obstetrician to monitor the position of the foetus while inserting a long hollow needle through the mother's abdominal wall and into the uterus. The obstetrician then withdraws a small amount of amniotic fluid, which is sent away for testing. Research Amniocentesis
Duchenne muscular dystrophy is the most common form of muscular dystrophy, and is transmitted by an X-linked recessive trait. Only males are affected and only females are carriers that pass the trait on. The disorder cannot be detected by amniocentesis. It affects about 1 in 10,000 boys. Symptoms of the disorder begin to appear in early childhood between the ages of two to six years. The pelvic and leg muscles are affected first. The child is slow in learning to sit up and walk. Progressive and rapid weakening of the muscles results in frequent falls, difficulty in climbing stairs, difficulty in getting up from the floor, and an awkward gait. Sometimes a curvature of the spine is associated with the disorder. Despite their weakness, the muscles appear unusually large and firm (psuedohypertrophy). At about early adolescence affected children are no longer able to walk. Children with Duchenne's muscular dystrophy are prone to chest infections and heart disorders due to progressive weakening of those muscles. Few sufferers survive into their teenage
years. Research Duchenne Muscular Dystrophy
The Probert Encyclopaedia was designed, edited and programed by
Matt and Leela Probert
Abbreviations
Research Amniocentesis
