- How accurate is the IONA® test?
The IONA® test has an overall accuracy of 99.99% for T21 and a less than 0.2% failure rate.
- What is the false positive rate?
Less than 1% of pregnant women who receive a high risk result from the IONA® test go on to have a follow-up invasive test which confirms that the fetus is not in fact affected with trisomy 21, 18 or 13.
- How is the sample taken?
A simple blood sample is taken from your arm by a healthcare professional. The test can be performed from the 10th week of pregnancy.
- What is the current method of screening?
Currently most healthcare systems offer pregnant women the combined test which includes a fetal ultrasound and blood test performed between 11-13 weeks into the pregnancy. The ultrasound looks at multiple aspects of the developing fetus, but particularly at the skin fold at the top of the spine where it meets the skull, this is called the Nuchal Translucency (NT). The blood test measures the levels of two hormones: hCG and PAPP-A. The current combined test has a ~85-90% detection rate and ~5% false positive rate.1
- Is the IONA® test replacing the 11-13 week dating scan?
No, it is recommended that you still have this dating scan at 11-13 weeks to assess the baby's growth and development. The IONA® test or any other non-invasive prenatal DNA screening test will not replace this dating ultrasound.
- Is the IONA® test 100% conclusive?
No, a cfDNA test (NIPT) cannot be 100% conclusive due to naturally occurring biological instances. For example, where the fetal DNA differs from the placental DNA (confined placental mosaism). The IONA® test is a screening test that analyses a combination of maternal and placental DNA, not DNA from the fetus.
- How long will it take to get the results?
Once the sample is received at the laboratory it can take between 2-5 working days to perform the test. >80% of samples are currently reported within 3 days of sample receipt. The data from the laboratory test is entered into the IONA® analysis software and an easy to interpret result report is generated and provided to your healthcare professional such as a consultant or midwife. The report will then be discussed with you by your healthcare professional.
- What are my options if I have a high risk result for a trisomy?
If you get a “high risk” result, you will be contacted by your consultant or midwife. The next steps should be discussed with a healthcare professional in the context of all available clinical findings, including advising for the need for genetic counselling or additional diagnostic testing (e.g., amniocentesis).
- Can I have the IONA® test if I have twins?
The IONA® test is suitable for twin pregnancies. However, in dichorionic twins, the test sensitivity is reduced from >99% to about 95%. Dichorionic means there are two placentas, which occurs with non-identical twin and some identical twin pregnancies.
- Can I have the IONA® test if I have had a blood transfusion?
The accuracy of the IONA® test may be affected if the mother has undergone a non-leucocyte depleted blood transfusion in the last 12 months. Suitability for the IONA® test should be discussed with your healthcare professional.
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