- Why is it
- How to prepare
The test prenatal non-invasive also known as non-invasive prenatal diagnosis, is a screening method for the discovery of chromosomal abnormalities specific during pregnancy.
And a blood test highly specific that examines fetal DNA in maternal blood to determine how much your child is at risk for Down syndrome (trisomy 21), trisomy 13, trisomy 18, or sex chromosome abnormalities such as the Turner syndrome.
The test può also be used to determine the sex of the child and his rH factor. Currently, prenatal testing non-invasive is available (recommended) only for women who have certain risk factors può help you avoid other tests that put at risk the pregnancy. Who takes care of you or a geneticist can discuss with you the advantages you might have and on how to interpret the results.
The test is not invasive è più sensitive and specific of the traditional screening of the first and second quarter, and può often helping women who have some risk factors to avoid invasive tests, such as:
- amniocentesis: during this procedure a small amount of; liquidò that surrounds and protects the baby during pregnancy (amniotic fluid ) is withdrawn from the uterus for analysis;
- chorionic villus sampling: during chorionic villus sampling, a small sample of the placenta is taken for testing.
amniocentesis and chorionic villus sampling are both at a slight risk of miscarriage.
The person who takes care of you può recommend the prenatal test non-invasive perché:
- do you have risk factors of having a child with chromosomal abnormalities. The test prenatal non-invasive può to establish how much your child is at risk for a chromosomal abnormality. The risk factors may include age; advanced maternal or have previously had a child with Down syndrome (trisomy 21),trisomy 13 or trisomy 18. Anyone who follows you can; also recommend the noninvasive test if you are worried about the result of the other prenatal testing
- you are a carrier of a genetic abnormality recessive disorder such as Duchenne muscular dystrophy or a disorder linked to the sex chromosome, for example haemophilia, which affects only males. The testing pre-christmas non-invasive può to determine the sex of your baby more easily by ultrasound. It può to determine the sex of your child but, it willà to determine if your child has the disease. Based on the result of the testing, a genetic counsellor può help you understand the next steps to do.
- you are rH negative: the test prenatal non-invasive può find the Rh factor of the child. If you are Rh negative and your baby is positive you could produce antibodies anti-Rh after exposure to red blood cells of your baby. This is called to become aware of,usually not with the first pregnancy but later.
While the test prenatal non-invasive &is currently recommended for women who have a high risk of having a child with chromosomal abnormalities, the research seeks to understand how può be useful to other women. Are carried out research to find out what other chromosomal abnormalities and genetic conditions can be discovered through this type of test.
The test prenatal non-invasive, involves no physical risks to you and your child. The test può cause ansietà but canò help you avoid more invasive tests, treatment or monitoring during the pregnancy. It is necessary to keep in mind, however, that the test prenatal non invasive non è a screening for all genetic conditions or chromosomal anomalies.
If you are interested in the diagnosis of non-invasive prenatal talk to people who follows you of the availabilityà. Remember to check if your insurance covers the costs.
Before you submit to the non-invasive prenatal diagnosis, who follows you, or a genetic counselor will explain the possible results and what they mean for you and for your child, make sure you place all the questions that you have concerning this test.
What to expect
The testing pre-christmas non-invasive può be run from the 10ª week of pregnancy. The test consists in taking a sample of maternal blood that is sent to the laboratory. The laboratory analyzes the DNA of the maternal and fetal the blood sample. A quantity; the greater of chromosome 21 indicates, for example, the possibilityà of the presence of trisomy 21 in the baby. Trisomy 21 is the cause of Down syndrome. Usually the test results are available after two weeks.
Who is following you, or a genetic counselor will explain to youà the result of the test prenatal non-invasive and may be:
- the chromosomal anomalies: if the test result is normal you may not need more testing. If, instead, the witness indicates that there is a probability, so that your baby has a chromosomal abnormality, there sarà offered to perform an amniocentesis or a chorionic villus sampling to confirm the diagnosis;
- the fetus sex: if you are carriers of a recessive abnormality X-related and the result of the examination indicates that the fetus is a girl you can not do other tests. If the test indicates that you have a baby you will be offered amniocentesis or chorionic villus sampling, tests that are used for genetic diagnosis;
- the Rh factor: if you are Rh negative and your test result indicates that your baby is Rh negative, you need no medication to prevent your body from producing antibodies to Rh during pregnancy. If the test results indicate that your child is Rh positive and you are previously aware your child will be carefully monitored.
chromosomal abnormalities may not be correct. If you’re diagnosed with a chromosomal abnormality to your baby you will need to decide whether to continue the pregnancy, or which steps to take to care for the child during the pregnancy or after he or she is born.
Who is following you, or the genetic counselor can help you by answering the questions to all of the questions that you have. Remember that regardless of the results of the noninvasive test if you have a risk factor that indicates that your child is at increased risk of chromosomal abnormalities, you can decide to submit to amniocentesis or chorionic villus sampling.
Test on fetal dna in maternal blood NIPT, as it should be used
prenatal Testing non-invasive: many false positive
Amniocentesis can goodbye, coming in a blood test
invasive prenatal Diagnosis, amniocentesis
a complete Guide to pregnancy
Source: Mayo Clinic
26 aprile 2015