The SAFE test (NIPT) is currently the most advanced non-invasive pregnancy screening available for parents who would like to determine if they have a low probability or high probability for their baby having the conditions Down’s syndrome, Edwards’ syndrome or Patau’s syndrome. The SAFE test is available from as early as 10 weeks of pregnancy, for early screening before the NHS Nuchal Translucency scan. NIPT can be performed after the NHS 12-14 week Nuchal Translucency Scan, or even in the mid term of pregnancy after the 20 week anomaly scan.
It has been discovered that a blood sample taken from the mother from 10 weeks of pregnancy onwards can be analysed for cell free DNA (cf DNA), which represents a sample of the fetal-placental DNA derived from placental trophoblasts, in the mother's blood.
The SAFE prenatal screening method involves taking a safe blood sample from the mother’s arm. There is no increased miscarriage risk to your baby from having this simple, safe maternal blood test. The cell free DNA (cfDNA) which is present in the mother’s blood is then analysed, the results determine if there is a high probability or low probability of the baby having one of the three screened conditions; Down’s syndrome, Edwards’ syndrome and Patau’s syndrome. These conditions are also known as Trisomy 21, Trisomy 18 and Trisomy 13.
The SAFE Non Invasive Prenatal Test can be used in twin, singleton donor and surrogate pregnancies. You can also choose to find out the sex of your baby by looking at baby’s X chromosomes, this is optionally included with your SAFE Test. In some circumstances it may not be possible for SAFE to report on the sex of your baby, for example if you have Vanishing Twin. In monochorionic, identical, twin pregnancies SAFE can confirm the sex of each twin as it will be same. For dichorionic, non-identical, twin pregnancies SAFE cannot confirm the sex of your babies. This can later be confirmed by ultrasound.
The SAFE Test is one of the most accurate non invasive prenatal tests to determine the chance of the presence of three most commonly screened for chromosomal conditions in pregnancy (T21, T18 and T13). It is the non invasive prenatal test with the lowest test failure rate, therefore many parents to be chose the SAFE 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 Downs syndrome (T21), Edwards syndrome (T18) and Pataus syndrome (T13) are born to mothers of all ages, maternal age increases the likelihood of the presence of these conditions. The SAFE test analyses the cfDNA in the maternal blood, to determine if there is an increased likelihood that your baby has an extra chromosome present.
The SAFE NIPT is processed and analysed for The Birth Company by St Georges Hospital Laboratory in London. Due to the close proximity, most NIPT results are back within 7 calendar days. In some circumstances results can take longer.
Parents to be who wish to find out the likelihood that their baby has one of three chromosomal conditions; Down’s syndrome (T21), Edward’ syndrome (T18) or Patau's syndrome (T13) choose the SAFE Test. The Harmony cfDNA test can be performed from 10 weeks of pregnancy, two weeks earlier than the NHS 12-14 week screening. The SAFE test has a greater sensitivity, specificity and higher positive predictive value (PPV) than the Nuchal Translucency screening, also known as the Combined Test. The SAFE cfDNA Test offers early reassurance and can reduce unnecessary anxiety and invasive testing caused by less effective prenatal screening methods.
SAFE is the only NIPT which offers prenatal screening 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 sensitivity and the positive predictive value of the Nuchal translucency screening).
The Nuchal Translucency screening, or combined test, offered by the NHS determines a background chance based on maternal age. From the 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 positive predictive value (PPV) of the test, meaning that those over 35 are more likely to receive a high probability result, even if the baby does not have the condition.
The SAFE test has a higher positive predictive value than Nuchal translucency screening. This means less high probability results where the condition is not actually present. We do not use the term false positives, as these are screening tests therefore they do not determine positives or negatives. They offer likelihoods.
The SAFE NIPT is particularly recommended for those over 35 years of age, parents to be who have had 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.
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 £120 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 £120 - £180 depending on gestation. The additional amount will be refunded to you.
Please note in the instance of a repeat full test failure, the SAFE test laboratory fees may be refunded. A fee for the appointment services provided will be retained.
Please note Anticoagulation therapy (commonly called blood thinners) can increase the possibility of receiving No Result for your NIPT. Please leave as long between administering your dose and your NIPT appointment as possible. For example, if you administer in the evening and have an early morning appointment, either change to an appointment late in the day, or refrain from your evening dose. If you administer in the morning, refrain from that dose until after your appointment. If you have any queries regarding this, please contact our team firstname.lastname@example.org.
For further information please see below:
Anticoagulation Therapy Publication
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 Downs syndrome, Edwards syndrome or Pataus syndrome.
The Nuchal Translucency Scan is a method of screening offered by the NHS from 12 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’s syndrome, Edwards’ syndrome and Patau’s 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 SAFE Non invasive prenatal testing (NIPT) became available many parents to be 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 positive predictive value (PPV) is less than 15%, meaning the actual number of high probability pregnancies that are later confirmed to have the condition Downs syndrome is less than 1 in 6.
When screening for Down’s syndrome using the SAFE Non Invasive Prenatal Test, the detection rate is 99% and positive predictive value (PPV) 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). You can use the NIPT Positive Predictive Value calculator here to calculate your PPV for each condition here:
This means using SAFE NIPT, the actual number of high probability pregnancies confirmed to have the condition Down’s syndrome vary from 1 in 2 (50%) confirmed with the condition to 9 in 10 (90%) of babies confirmed with the condition, depending on maternal age and other factors.
For Edwards Syndrome the SAFE NIPT positive predictive value (PPV) is 2 in 5, or 40% likelihood that the baby is confirmed to have the condition. For Pataus Syndrome the SAFE NIPT PPV is reported as 1 in 2, or 50% of babies confirmed to have the condition after a high probability SAFE NIPT.
The results of the SAFE 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 SAFE Test.
Yes. Structural conditions such as brain, face, stomach, kidney, bladder and limb conditions, aswell 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 anomaly 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 result when a demised twin is present. Some evidence suggests that performing Non Invasive Prenatal Testing 8 weeks after the demise of the second twin may reduce the likelihood of a false positive result.
A high probability result does not confirm the presence of a chromosomal condition in the live twin, only invasive testing can prenatally confirm or exclude chromosomal conditions.
The SAFE Non Invasive Prenatal Test is unable to give a result for the fetal sex in vanishing twin pregnancies.
The SAFE Test, including an ultrasound scan and prenatal screening counselling from our Specialist Sonographers costs £500.
Appointments after 5pm, weekend and bank holiday appointments incur a £50 surcharge.
SAFE NIPT appointments with our Consultant Dr Gibb incur an additional charge of £150.
The SAFE NIPT has a turnaround time of approximately 7-10 days this is due to the samples being processed in London (Please note in some circumstances results can take longer). Parents to be 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 pregnancy scan is aware of this. If the test is high probability then you should return to The Birth Company 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. https://www.gov.uk/topic/population-screening-programmes/fetal-anomaly
Depending on how many weeks pregnant you are, we recommend you take the opportunity to have a 12 to 14 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’s syndrome, Edwards’ syndrome and Patau’s syndrome. The 12 to 14 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 anomaly 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 Anomaly 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 anomaly scan is a very important ultrasound scan during pregnancy.
More information about Downs, Edwards’ and Patau’s Syndrome can be found here:
More information about screening tests offered in pregnancy can be found here:
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For cancellations, a full refund of your appointment fee will be given with 24 hours notice. If less than 24 hours notice of cancellation is given, a £50 cancellation fee will be applied. Our full terms and conditions can be found here: Terms and Conditions
Some early pregnancy ultrasound scans are performed using a transvaginal probe technique. This technique is used to view the pelvic anatomy optimally, as the ultrasound probe can transmit safe ultrasound waves more directly to the pelvic area. In later stages of pregnancy, it may be advised to perform a transvaginal ultrasound scan to have a closer look at a baby’s anatomy, or to assess the maternal cervix.
There is no clinical risk associated with performing a transvaginal ultrasound scan. Transvaginal ultrasound scans can safely be performed during episodes of vaginal bleeding.
It is important that you understand the procedure that is associated with this examination.The ultrasound transducer will be placed in the vagina (the probe is prepared using high grade medical disinfectant)
Below is a link to our Transvaginal Ultrasound Consent Form. This must be completed ahead of your appointment to confirm whether you consent or do not consent to having your scan performed transvaginally.
We had received possible worrying news from our NHS anomaly scan, without much information provided or confirmation. I am so pleased that we came to The Birth Company for reassurance, as we are now extremely happy that everything is fine. Shahrzad was fantastic and went through the whole anomaly scan thoroughly, explaining everything and looking in detail at each area. Nothing was rushed and she took her time to make sure baby was in the correct position to get the best results. We can’t thank her and Dr Gibb enough for the confidence they have given us. Would highly recommend The Birth Company for all scans.
' Professional and reassuring 'Helen Campbell
The sonographer was ready as soon as I arrived, and she was extremely calming, personable and professional. The scan and blood test where efficient without feeling rushed and all very easy. These appointments can feel uneasy and make you feel anxious but I felt reassured and in professional hands the whole time
I saw Kate throughout my first pregnancy and am now doing so again with my second. She is absolutely amazing, she explains everything really clearly, and has answered all sorts of bizarre questions and worries I have had. On top of being clinically excellent she is also just the loveliest person and always a pleasure to see.Sarah Elliott
We had the harmony test with the Birth Company and had a reassurance scan with sonographer Kirsty McGarry who was absolutely lovely and really put our minds at rest. We had been scared by our NHS dating scan and left feeling like there was something wrong. We explained the situation and was treated very professionally and with good care. Also speedy appointments also as I had phone in the morning and got an appointment by afternoon. So thankful.Ashley and Tom
Really friendly, efficient service. Great experience overall. Had the Panorama. My appointment was with Kate who was absolutely fantastic. The results came really quickly. Have a comparison with private healthcare elsewhere and must say that The Birth Company was just how I would like to be treated when I pay for medical services - attentively, calmly, friendly, in a pleasant environment that doesn't look like hospital. Top marks!Anna
' Efficient, friendly and always on hand to provide last minute appointments 'Hannah Murphy
The Birth Company has been excellent, providing timely scans and blood tests during my IVF treatment abroad. Staff are always friendly and extremely efficient. I would highly recommend coming here.
' Professional and friendly 'Lyndsey Dilla
When I first contacted the Birth Company I spoke to Danielle. She was fantastic. She went above & beyond to put me at easy & make the journey from Kent as stress free as possible. Every staff member that myself and my husband have come into contact with have been approachable, professional and friendly. Kate scanned me the first time and put me completely at easy. Lisa on reception is professional and very approachable. Highly recommended
' Highly recommended 'Emelie
Donald was so lovely! I was so nervous as I have a bad history and he was super quick and confirmed my baby's heartbeat as quickly as he could. He spent time showing me the baby and the anatomy and it was the best money I have ever spent! The reception girls were lovely too - considering they deal with babies day in day out they were super excited for me! Thank you so much one and all! If only I lived in London and could have all my scans with you!
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