Prenatal Screening :: essays research papers

Prenatal screeningScreening for Down syndrome is useable to about 53.5% of mothers on a maternal age basis, and the remaining 46.5% of health boards provide serum screening for all ages. There are some(prenominal) methods used in prenatal screening, these are usually used separately, and a number of factors are taken into account to determine which method should be used. Amniocentesis has been around for 20 y stiletto heels and is probably the most soundly known screening method. It involves block outing a sample of the amniotic legato surrounding the foetus, ultrasound is used to guide a needle by dint of the abdomen, into the womb and a elegant amount of amniotic fluid (20ml) is removed. The summons is usually carried out at 14-16 weeks. Amniocentesis tests for chromosome disorders, and is 99.8% reliable for chromosome number, there is that a risk of miscarriage (usually 1/250 or less) after the procedure. This is angiotensin converting enzyme of the reasons why amnio h as only been offered to over 35s (since they have a frequently higher risk of having a Down syndrome child)(Webb 1990). Previous studies on amniocentesis concentrated on problems that might arise during pregnancy or forthwith after, these studies found that children whose mothers had amniocentesis are more apparent to have respire problems in the first few days after birth. A composition performed by Jo-Anne Finegan in Toronto followed 88 women who had, had amniocentesis, there was an increased incidence of ear infection in this group. Finegan tested the stiffness of the eardrum and found children in the amniocentesis group were more than three times as likely to have abnormal readings. It is thought that there is a disruption of the diffused balance of pressure across the eardrum when the amniotic fluid is removed, which could get the problems(Webb 1990). Chorionic villus sampling is another form of sampling, it involves taking a small piece of placenta and genetic testing i s carried out on it, there is a slightly higher chance of foetal loss with this procedure (Dick 1996). A more recent form of prenatal testing involves serum markers. kind is taken from the pregnant women and the maternal blood is tested for three hormones, this test is called the triple screen test. The three hormones tested are alpha foeto-protein (AFP), human chorionic gonadotrophin (HCG) and oestradiol (E3). AFP is based on the fact that Down syndrome foetuses take to the woods to be smaller on average, have smaller placentas and thus give up less AFP.