That blood test can come out with false positives or negatives. It's not a very reliable test. The most reliable test is the amnio. The ultrasound is not entirely reliable on this test either. You have the right, however, to decline any test that you feel unnecessary. So, if you do not want the amnio, tell them no.
2006-07-24 17:06:39
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answer #1
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answered by Star-chan 2
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I am not expecting, but I know someone that has a baby and their test show bad news also. They decided not to do anymore test untill the baby was born. They knew they werent going to abort it. So they just begin researching Downs and way to help the child after it got here. The reason they didnt do anymore more test until the baby was here, was that their was another woman that had all the test done showed all was well, but had a Downs baby.
I am not sure if that helped you or not, the best of luck. I believe that Downs children a a true blessing to the world.
Here are some site that you might want to look at incase you do have a child with Downs or know someone that does.....I will have to put them on another page not enough room on here.
2006-07-24 20:08:56
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answer #2
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answered by mandy_42003 2
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Here's some information from some books of mine that I think you might find interesting.
Book 1: "Down's syndrome: This chromosomal disorder happens when a fertilised egg has 47 chromosomes instead of the usual 46.
In most cases, the egg itself is defective, because it's formed with the extra chromosome; the sperm may be affected in the same way. This type of Down's syndrome is known as trisomy. Less commonly, one parent may have a chromosomal abnormality, causing the child to inherit faulty chromosomal material. This is known as translocation.
The incidence of Down's syndrome rises sharply, with the age of the mother, particularly over 35, but various tests can identify the condition of the fetus. Chorionic villus sampling or nuchal scanning (scanning of the fetal neck) can be carried out at 10-12 weeks. At around 15 weeks, amniocentesis can be offered to high risk mothers.
The risk of having a Down's syndrome baby can be assessed at around 11-14 weeks using a special ultrasound scan called a nuchal scan ('nuchal' means neck). A shadow of a particular size and shape at the back of the baby's neck may indicate a higher risk of chromosome defects such as Down's syndrome if it is thicker than normal in relation to the age of the mother. If the nuchal scan shows there may be Down's, the mother will need amniocentesis to confirm the diagnosis. In fact, many centres now only carry out amniocentesis after a nuchal scan has been done.
The nuchal scan is often combined with blood tests and can detect about 90 per cent of babies with Down's syndrome. It may also be falsely positive - an abnormal nuchal scan does not mean your baby has Down's syndrome. You need to think carefully about what you'd do if the test was positive before deciding to have it done. Chrorionic villus sampling (CVS) may also be suggested as a way of detecting problems.
Serum screening (Bart's triple test) This test was developed by St Batholomew's Hospital in London. A sample of the pregnant mother's blood is taken between 14 and 20 weeks to measure the levels of three substances - oestriol, human chroinic gonadotrophin, and alpha-fetaprotein. The results are assessed in relation to the mother's age to predict the chance of her baby suffering from Down's syndrome"
Book 2:
"First trimester screening: First trimester screening for Down syndrome involves an ultrasound test to check for excess fluid behind the fetal neck (nuchal fold thickness) and a blood test for high levels of plasma protein A and hCG, two hormones produced by the fetus and passed into the mother's blood stream. (Researchers are looking, too, at whether the absence of a nasal bone in the fetus, as shown on the ultrasound, may also indicate a higher risk of Down Syndrome) Women whose results are abnormal would be ffered amniocentesis.
When is it done? Between the 10th and 14th weeks
How is it done? Both ultrasound and the blood test are simple procedures.
Second trimester screening: Quadruple screen: The quadruple screen is a simple blood test that measures four hormones produced by the fetus into the mother's bloodstream: alpha-fetaprotein (AFP), hCG, estriol and inhibin. (Researchers contnue to study other substances in the mother's blood that may eventually be added to the blood test to improve it's ability to detect birth defects). Elevated levels of MSAFP in the mother's blood can indicate a neural tube defect in the baby such as spina bifida (a deformity of the spinal column). Abnormally low levels suggest an increased risk of Down syndrome of other chromosomal defect. The quadruple screen cannot diagnose a birth defect; it can only indicate an increased risk. And because this is only a screening test, any abnormal result simply meas that further testing is needed. In fact, the false positive rate is extremely high. Only 1 or 2 out of 50 women with abnormally high readings will eventually prove to have an affected fetus. In the other 48, further testing will reveal that the reason MSAFP levels are abnormal is that there is more than one fetus, that the fetus is either a few weeks older or younger than originally thought, or that the results of the test were just wrong. If the woman is carrying only one fetus, and the ultrasound shows the fates are correct, an amniocentesis is offered as a follow-up.
When is it done? Between the 15th and 18th weeks. The results are usually avaiable within one week.
How safe is it? Since the quadruple screen requires only a blood sample, it is completely safe. The major risk of the test is that a false positive may lea dto follow-up procedures that present greater risk - and, in rare cases, to therapetuc or accidental abortion of normal fetuses.
Before you consider taking any action on the basis of prenatal testing, be sure an experienced physician or genetic counsellor has evaluated the results. Get a second opinion if you have any doubts"
Book 1: 'Conception, pregnancy and birth', Dr Miriam Stoppard
Book 2: 'What to expect when you're expecting' Heidi Murkoff, Arlene Eisenberg and Sandee Hathaway
2006-07-24 20:07:07
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answer #3
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answered by Jade 5
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