![]() ![]() They can be due to placental mosaicism i.e. There is always a chance of an NIPT result being a false positive.įalse negative and false positive results may occur with any form of NIPT. There is always a small chance of an NIPT result being a false negative.Ī result indicating high probability of a specific disorder should be confirmed by invasive cytogenetic testing, for example, CVS or amniocentesis with cytogenetic analysis, before making major decisions regarding the pregnancy. Utility:Ī result indicating low probability of a specific disorder is usually reassuring regarding that disorder, but it must be interpreted in the light of other factors which influence the risk of the fetus having abnormal chromosomes. There is also the option for a genome-wide NIPT screen which covers chromosome macro-duplications and -deletions (larger than seven million base pairs) and rare monosomies and trisomies. There is the option to screen for fetal sex (no charge) or sex chromosome abnormalities such as monosomy X (Turner syndrome), XXY (Klinefelter syndrome), XYY and XXX (no charge) or both. The standard disorders covered by NIPT are: Both of these procedures carry around a one in 100 risk of causing a miscarriage.Non-invasive prenatal testing is a test of a pregnant woman's blood to screen for various chromosomal disorders in the developing fetus. This reduction in the false positive rate reduces the number of women being offered invasive testing, using chorionic villus sampling (CVS) or amniocentesis. The Harmony test has a false positive rate of 0.1%. What are the other screening tests available and why is the Harmony test better?Ĭurrent screening tests(Nuchal Translucency scan)have a false positive rate (that is, the results suggest a problem when the baby is in fact healthy) of around 4%. For this reason, a procedure such as an amniocentesis or chorionic villus sampling (CVS) may be recommended following a high probability Harmony result. What if I have a high probability test result?Ī high probability result does not mean your baby definitely has a chromosomal abnormality although it is highly likely. If the test result shows a high probability result, then the probability that your baby has a chromosomal abnormality is greater than 99%. If the test result shows a low probability result for a chromosomal abnormality, then your baby will have a probability of less than 1 in 10,000. The Harmony test is now one of the most accurate and non-invasive tests available to predict the chance of your baby having a chromosomal abnormality. In the event of a high probability result, we will provide you with a referral letter to a Fetal Medicine Unit in an EPAU in order to discuss your next steps. If it reports low probability, no further follow up required. The results will come back as 0.01% probability which is your low chance result or 99.9% which is your increased probability result. Once you receive the email/results you can always contact us if there is anything you need to discuss. You will be contacted by a member of our team who will explain the test results to you. Your results will be reported to you within 8 working days of your appointment. You may require an ultrasound scan to confirm gestational age, if you have not already had an early pregnancy scan completed. You will then be asked to complete a consent form. You can have the Harmony Test performed from 10 weeks gestation on How Is The Test Performed & How Long Will It Take To Get The Results?īefore the blood test is taken, the sonographer will discuss the test with you to answer any questions you may have. When can I have the Harmony Test performed 80% of babies with Patau’s syndrome (Trisomy 13). ![]()
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