Available to women from 16 years of age.
This service includes a Non Invasive Prenatal Test (NIPT for short, sometimes called the Harmony™ prenatal blood test from Ariosa Diagnostics Inc) and an ultrasound scan. Your blood needs to be taken either by us at the time of your appointment or privately by your midwife, GP or local phlebotomist.
Note that the results from your baby's DNA blood test are normally available approximately 7 working days after your appointment and we recommend that you present your results to your usual healthcare professional whose contact details we take at the time of booking. Your choice of a free rescan may be appropriate if we are unable to perform the primary purpose of this scan.
All scans are performed by a qualified Sonographer with diagnostic obstetric scanning experience.
To test for Down's syndrome and certain other genetic conditions (T18 and 13 and Turners syndrome) from a maternal blood sample.
The ultrasound scan will determine viability, if single or multiple fetus are present and accurately date your pregnancy. Very occasionally it may involve transvaginal / internal scanning.
Need to expose lower abdomen so ideally wear 2 piece garments i.e trousers or skirt and top.
Drink 0.5 Ltr (1 pint) clear fluid approx 1 hour before appointment time.
Please do not empty your bladder before the examination.
Please bring your hand held notes with you to the scan.
The Harmony prenatal blood test is analysed in the UK by our authorised partners TDL . By booking a NIPT appointment with us you are agreeing to your personal information being shared with TDL solely for the purpose of this test. Your express permission will also be asked during your appointment.
Cell-free fetal DNA (cff DNA) comes from the placenta.
It is first detectable from about 4-5 weeks’ gestation and reaches the required level needed to test for Down syndrome by 10 weeks’ gestation in most pregnancies.
With more than 99% accuracy, NIPT is more accurate than the first trimester combined test or second trimester quadruple test for estimating the chance or the risk that the baby has Down syndrome.
There may be some factors which cause an inconclusive result (see further reading) and an invasive test may be required for accurate determination.
We can assist with your Healthcare professional in these circumstances.
There are three possible results from NIPT for Down syndrome:
Predicted to be affected by Down syndrome. An invasive test is required to confirm the result.
Highly unlikely to be affected by Down syndrome.
Inconclusive results happen in up to 4% of cases. This is usually because the proportion of fetal DNA present in the sample is not high enough to give an accurate result. NIPT may be repeated with the hope that the cff DNA levels will have increased due to the increased gestation. NIPT detects around 98% of all babies with Down, Edwards and Patau syndromes.
The relative proportion of cell-free fetal DNA is reduced in women with a high BMI as they have more of their own cell-free DNA circulating in their blood.
This may increase the chance of getting an inconclusive result.
It is now possible to use NIPT to detect Down syndrome and three of the other common aneuploidies: Edwards syndrome, Patau syndrome and Turner syndrome.
Please see further reading for additional conditions NIPT can detect.
The following links may provide you with further, useful information regarding our NIPT with scan service: