The PRENATALSAFE® NIPT Test is one of the most accurate NIPT tests to determine the chance of the presence of three most common chromosomal conditions in pregnancy (T21, T18 and T13). It is a non-invasive prenatal test with extremely low-test failure rates; therefore, many parents choose the PRENATALSAFE® test if there is an increased chance of test failure due to factors such as high maternal BMI.

Tiny structures inside your baby’s cells called chromosomes carry the genes that determine how your baby develops. There are 23 pairs of chromosomes per cell, however changes may occur during the production of sperm or egg cells which can lead to your baby having an extra chromosome. Although babies with Down syndrome (T21), Edwards syndrome (T18) and Patau syndrome (T13) are born to mothers of all ages, maternal age increases the likelihood of the presence of these conditions. The PRENATALSAFE® test analyses the cfDNA in the maternal blood, to determine if there is an increased likelihood that your baby has an extra chromosome present.

PRENATALSAFE® NIPT test can be offered for Vanishing Twin pregnancies. This is particularly important, as a Vanishing Twin pregnancy can affect the prenatal screening offered to you by the NHS. They may determine a likelihood for chromosomal conditions based on the Nuchal Translucency measurement at the back of your baby’s neck and your maternal age only (excluding the maternal hormone biochemistry, further reducing the accuracy of the Nuchal translucency screening). For vanishing twin pregnancies, the accuracy is slightly reduced compared to single or twin pregnancies.

The Nuchal Translucency screening offered by the NHS determines a background chance based on maternal age. From maternal age of 35 years of age onwards this background chance increases substantially. This increases the likelihood of receiving a high probability result from the Nuchal Translucency screening. Due to the limitation of the Nuchal translucency screening, this lowers the accuracy of the test, meaning that mothers over 35 are more likely to receive a high probability result, even if the baby does not have the condition.

The PRENATALSAFE® test has a higher accuracy than Nuchal translucency screening. This means less higher probability/ ‘Detected’ results where the condition is not actually present.

The PRENATALSAFE® NIPT test is recommended for all age groups but particularly for patients above 35 years of age, prospective parents with a high probability result in their current or previous pregnancy, or a confirmed chromosomal condition in a previous pregnancy. It is for those who wish to avoid unnecessary invasive testing, which carries a risk of miscarriage.

• An ultrasound scan is always performed prior to the PRENATALSAFE® blood test. This ensures that your baby is healthy, with a strong heartbeat and growing well. This scan will also confirm if it is a singleton, twin, or vanishing twin pregnancy. Our specialist sonographer will check that baby is developing well and confirm your estimated due date, or EDD. Your baby must measure over 10 weeks gestation for the PRENATALSAFE® NIPT to be performed, therefore it may be best to wait until a few days past 10 weeks of pregnancy to visit us for your appointment to ensure your baby is developed enough.
• Our Specialist Sonographer will discuss the pros and cons of the three Non-invasive prenatal tests available; TDL VeriSeq v2 by Illumina NIPT, Panorama NIPT or PRENATALSAFE® NIPT. This prenatal screening counselling will help you choose the best test for baby and for you.
• Once the pregnancy scan has been performed and your prenatal screening options discussed, a PRENATALSAFE® request & consent form will be given to you to read and sign. If you have any questions, are sonographers are here to answer them. Please find a copy of the PRENATALSAFE® request & consent form here.
• A simple blood test is then taken from the vein of the mother’s arm like any other blood test. There is no risk to your baby from having this blood test performed.
• The specialised PRENATALSAFE® blood sample tube is packaged and collected by a dedicated driver of Eurofins to reach their laboratory in Guildford on the same day for processing and analysis.
• NIPT screening results determine if you have a low or high probability for Down syndrome, Edwards syndrome or Patau syndrome. The PRENATALSAFE® NIPT test report can also tell you the biological sex of your baby.
• If you receive a high probability/’Detected’ result, our expert team will discuss pathways, including further investigations such as detailed ultrasound scans, invasive testing, counselling or referral to your Fetal Medicine Unit (FMU). This can also be discussed with our Consultant.
• There can be circumstances where our Specialist Sonographers does not recommend the PRENATALSAFE® NIPT for your pregnancy. Each pregnancy is different. Other prenatal screening, diagnostic testing or further pregnancy care may then be recommended. Our Consultant provides support and advice where needed.

Please note We recommend using our pregnancy calculator, or contacting our specialist admin team if you are unsure of the best time to attend for your NIPT. NIPT can be performed from 10 weeks of pregnancy. If you are too early for NIPT when you attend for your appointment, an additional charge of £166 will be required to cover the cost of the additional appointment and scan required. 

Please note in the circumstance that during your appointment an ultrasound scan is performed but we do not proceed to the NIPT, a fee will be taken for the price of the scan. This can vary between £166 - £300 depending on gestation. The additional amount will be refunded to you.

Please note in the instance of a repeat full test failure, the PRENATALSAFE® test laboratory fees may be refunded. A fee for the appointment services provided will be retained.

PRENATALSAFE®  results typically take 5–7 days to be returned. The exact timing depends on:

• The day and time the blood sample is taken
• Whether the laboratory needs to perform additional analysis

On average, results are received within 5 days.

Result Communication

As soon as we receive the laboratory results, a member of our team will call you to explain the findings. A copy of the results will then be emailed for inclusion in your maternity notes.
Our team is available in the clinic daily from 8am to 8pm, including Saturdays and Sundays. Laboratory portals are monitored throughout the day, though results are most commonly received in the late afternoon.

Sample Requirements and Retesting

The SAFE Test requires one tube of blood. If the initial analysis is successful, results are typically returned within the standard timeframe.
If the analysis is unsuccessful, the lab will report a “No Result Test Failure.” In such cases:

• The patient will be invited back to the clinic for a rescan and repeat blood draw
• A rescan is recommended as fetal development progresses rapidly during early gestation

Delays

In rare instances, results may take longer than 7 days. We understand that waiting can be stressful and will make every effort to communicate any delays promptly once notified by the laboratory.

• The PRENATALSAFE® NIPT report will determine whether you have a low probability or high probability for Down Syndrome, Edwards Syndrome or Patau Syndrome (Trisomy 21, Trisomy 18 or Trisomy 13). This can be particularly reassuring if you have received a high probability Nuchal translucency scan, or a sonographer has found a structural condition such as Renal Pelvis Dilatation or short femurs at your 20-week Anatomy scan.
• If you receive a low probability/’Not detected’ result, the likelihood of your baby having each of the conditions is less than 1 in 10,000. This means that we would expect less than one baby to be born out of ten thousand births with the condition Down syndrome, Edwards syndrome or Patau syndrome.
• If you receive a high probability/ ’Detected’ result, this will specify which trisomy condition there is a high probability of your baby having; Down syndrome, Edwards syndrome or Patau syndrome. This does not confirm that your baby has this condition, as this is a screening test only.
• Please note that the accuracy for NIPT varies between Down syndrome, Edwards syndrome and Patau Syndrome, between type of pregnancies and with maternal age. The accuracy for Down syndrome varies from 1 in 2 babies confirmed to have the condition to more than 9 in 10 babies confirmed to have the condition, therefore genetic counselling, further investigation and a supportive pregnancy pathway is recommended. During pregnancy, the only method available to diagnose if the condition is actually present in your baby is invasive testing such as chorionic villus sampling (CVS) or amniocentesis.
• Due to the nature of the PRENATALSAFE® test, there is <1% chance of receiving an ‘Inconclusive’ or no result from your NIPT blood sample. This is not a low probability, nor a high probability result. This happens in less than 1 in 100 samples, this does not mean that your baby has a condition present. It is most commonly because the PRENATALSAFE® blood sample probably had less than 2% Fetal Fraction, which is the minimum quantity of cfDNA needed to perform an accurate PRENATALSAFE® NIPT analysis. In most cases it is suitable to offer a redraw of the sample free of charge, including an ultrasound scan. ‘Inconclusive’ results are increased by maternal BMI greater than 30, as evidence supports that there is a negative relationship between maternal BMI and the quantity of cfDNA.
• If you have selected the option of finding out the biological sex of your baby, this will also be documented on the NIPT report. In some circumstances, PRENATALSAFE® is unable to accurately perform sex determination analysis.

PRENATALSAFE® Test 'Not Detected' Example Report

PRENATALSAFE® Test 'Detected' Example Report

There is an increased likelihood of test failure in certain cases, this includes but not limited to mothers using blood thinners and mothers with elevated BMI. Test failures can cause parents unnecessary concern.

If possible, we recommend waiting at least 2 weeks before giving another blood sample to perform your repeat NIPT, this will increase the percentage of fetal fraction available for the test and reduce the likelihood of receiving again an ‘Inconclusive’ /no result.

Prior to this advance in prenatal screening, doctors and screening midwives used the results of the Nuchal Translucency Scan to advise parents to be if they had a low or high probability of their baby having the conditions Down syndrome, Edwards syndrome or Patau syndrome.

The Nuchal Translucency Scan is a method of screening offered by the NHS from 11 to 14 weeks of pregnancy and includes several factors to determine this probability, including maternal age, the nuchal translucency measurement at the back of the baby’s neck and the maternal blood biochemistry (free ß-hCG and PAPP-A). This method is also known as the combined test. The greater the maternal age, the greater the background chance of the presence of the condition.

Nuchal Translucency screening test, or combined test, has a sensitivity of 84%. Parents to be who receive a high chance result are offered counselling by their screening midwife. This does not confirm the presence of the chromosomal condition. A diagnostic invasive test such as chorion villous sampling (CVS) or amniocentesis can confirm the presence or absence of the conditions Down syndrome, Edwards syndrome and Patau syndrome. A needle is used to take a sample of the pregnancy, through the mother’s tummy to allow for the analysis of fetal DNA. These invasive tests report a risk of miscarriage to the pregnancy of 1:100.

Since PRENATALSAFE® NIPT tests became available many parents chose this more accurate prenatal screening. For comparison, when screening for Down’s syndrome using the Nuchal Translucency scan, the detection rate is 84% and accuracy is less than 15%, meaning the actual number of high probability pregnancies that are later confirmed to have Down syndrome is less than 1 in 6.

When screening for Down’s syndrome using the PRENATALSAFE® Non-Invasive Prenatal NIPT Test, the detection rate is more than 99% and accuracy varies from 48% to 99% depending on maternal and pregnancy factors, including maternal age and the presence of an increased nuchal translucency measurement. The greater the maternal age, the greater the NIPT positive predictive value (PPV).

The results of the PRENATALSAFE® NIPT blood test has a high detection rate which will hugely reduce the need for unnecessary invasive testing by CVS or amniocentesis. This is great news for parents to be looking for reassurance in pregnancy.

It is important that an ultrasound scan is performed just before the blood test to confirm the pregnancy, and to check if there are twins or more. Our specialist sonographers will perform a detailed early fetal scan, early anatomy scan or anatomy scan depending how many weeks pregnancy you are when you visit us for the PRENATALSAFE® Test.

Yes. Structural conditions such as brain, face, stomach, kidney, bladder and limb conditions, as well as Spina Bifida. Poor growth and development will only be demonstrated on ultrasound scans, often not until the second and third trimester. If you would like further reassurance that your baby is developing and growing well, our specialist sonographers are trained to perform early Anatomy scans from 16 weeks of pregnancy.

Many miscarriages of pregnancy are caused by chromosomal conditions, therefore there is a high probability that there was a chromosomal condition present in the twin that has sadly passed. There is an increased likelihood of receiving a high probability/’Detected’ result when a demised twin is present. We recommend performing Non-Invasive Prenatal Testing at least 5 weeks after the demise of the second twin to reduce the likelihood of a false positive result.

A high probability/’Detected’ result does not confirm the presence of a chromosomal condition in the surviving twin, only invasive testing can prenatally confirm or exclude chromosomal conditions.

The PRENATALSAFE® Non-Invasive Prenatal Test will only report the presence or absence of the Y-chromosome for dichorionic twin and vanishing twin pregnancies.

If you are looking for a second opinion, please ensure that you provide us with your relevant ultrasound report ahead of your appointment to ensure that we can provide you with the best service. 

Ultrasound reports should be sent to bookings@thebirthcompany.co.uk

The PRENATALSAFE® NIPT Test, including an ultrasound scan and prenatal screening counselling from our Specialist Sonographers costs £450.

The PRENATALSAFE® NIPT test has a quick turnaround time of approximately 5 working days (Please note in some circumstances results can take longer). Prospective parents who have received high probability Nuchal Translucency screening result, or if the sonographer has found a condition present on ultrasound appreciate receiving results as soon as possible to provide reassurance, and to help plan their pregnancy pathway.

If the NIPT is low probability, then it is important that the sonographer or doctor performing the 12-week scan or 20-week Anatomy scan is aware of this. If the test is high probability, then you should return to HCA or your NHS Fetal Medicine Unit for further counselling and to develop a supportive pregnancy pathway.

Pregnant women are offered two routine ultrasound scans during pregnancy within the NHS, this is called the Fetal Anomaly Screening Programme 

Depending on how many weeks pregnant you are, we recommend you take the opportunity to have a 12-week pregnancy scan privately or with the NHS. The focus of the 12- week scan will change as you will already know if you have a low chance for Down syndrome, Edwards syndrome and Patau syndrome. The 12-week pregnancy scan will look at the development of your baby in detail, our Sonographers are highly trained to perform early fetal scans and early fetal Anatomy scans. These specialist private pregnancy scans and NHS scans look for structural conditions (these may exist without the presence of a chromosomal condition).

The other routine pregnancy scan offered by the NHS is around 20 weeks of pregnancy called the Anatomy scan. The purpose of this ultrasound scan is to assess your baby’s physical development and to look for 11 rare conditions, including head/brain and heart conditions. The 20-week Anatomy scan is a very important ultrasound scan during pregnancy.

The Harmony Test NIPT was the first NIPT available privately in the UK. This test was processed by The Doctors Laboratory (TDL UK).

Since September 2023 TDL are no longer offering the Harmony NIPT. They have replaced the Harmony NIPT with Veriseq v2 by Illumina NIPT.

This newer NIPT technology promises faster turnaround times, often as quickly as 2-4 days and lower test failure rates. We welcome this new technology, improving your pregnancy journey.

More information about chromosomal conditions can be found here:

• Downs Syndrome Association
• SOFT UK
• Patau's Syndrome 
• Edward's Syndrome 

More information about screening tests offered in pregnancy can be found here:

• Screening tests for your and your baby
• Screening tests for you and your baby translated versions