top of page

Blood Testing Services

Patient Information

Non-invasive prenatal testing (NIPT) analyses cell-free DNA circulating in the pregnant mother's blood. It is an option in prenatal screening for Down syndrome (trisomy 21) and other common fetal chromosomal conditions (trisomies 18 and 13).

About the test

DNA from the fetus circulates in the mother's blood. Cell-free DNA (cfDNA) results from the natural breakdown of fetal cells (presumed to be mostly placental) and clears from the maternal system within hours of giving birth. During a pregnancy, cfDNA can be tested to give the most accurate screening approach in estimating the risk of a fetus having a common chromosome condition sometimes called a trisomy. This occurs when there are three copies of a particular chromosome instead of the expected two. The test looks to detect the following trisomies:


  • Trisomy 21 is the most common trisomy at the time of birth. Also called Down syndrome, it is associated with moderate to severe intellectual disabilities and may also lead to digestive disease, congenital heart defects, and other malformations.

  • Trisomy 18 (Edwards syndrome) and Trisomy 13 (Patau syndrome) are associated with a high rate of miscarriage. These babies are born with severe brain abnormalities and often have congenital heart defects as well as other birth defects. Most affected individuals die before or soon after birth and very few survive beyond the first year of life.


The testing is non-invasive: it involves taking a blood sample from the mother. The pregnancy is not put at risk of miscarriage, or from other adverse outcomes that are associated with invasive testing procedures such as amniocentesis.


Clinical studies have shown exceptional accuracy for detecting fetal trisomies.

A ‘HIGH RISK' result is indicative of a high risk for a trisomy. The test identifies more than 99% of fetuses with trisomy 21, 97% of fetuses with trisomy 18, and 94% of fetuses with trisomy 13.

After the test, the number of women required to have a CVS or an amniocentesis is less than 1%.


It is important to note that if the test results show there is a HIGH risk that the fetus has trisomy 21, 18 or 13, it does not mean that the fetus definitely has one of these conditions, although it is highly likely. For this reason, in the event of a ‘high risk' (or positive) result, follow-up testing by an invasive procedure is recommended In the same way if the test results show that there is a ‘LOW RISK' that the fetus has trisomy 21, 18 or 13, it is unlikely that the fetus has one of these conditions.


However, there is a very small risk that not all trisomy fetuses will be detected. All results should be interpreted by a clinician in the context of clinical and familial data: patients should continue with their usual scan appointments following testing.

Who can have the test?

The test is suitable for any woman who has had an ultrasound scan to confirm that her pregnancy is either singleton or twins, that the fetus is alive, and that the fetal length is equivalent to a gestation of 10 weeks or more.


The test can be done in Twin pregnancies and in IVF pregnancies. 

The results will be ready in within 5 days and the results are normally sent on email.

Any unusual findings are however discussed with the patients over the phone. It is recommended that patients also have a NT scan either within the NHS or privately in order to measure the thickness of the NT. This will be discussed with you at the NIPT scan appointment. On occasion, the NT thickness may be measured at the scan appointment but this is not guaranteed as the scan is brief.


The risk calculated from the NT plus bloods ie. 1 in something chance, can be ignored in favour of the Harmony test result.

On the basis of the NIPT result and the ultrasound findings, a patient can decide whether or not she wants to have an invasive procedure (for example, CVS or amniocentesis).

Repeat Samples

There needs to be enough fetal DNA in the maternal blood to be able to provide a result. If there is insufficient fetal DNA in the sample (occurring in less than 2% of cases), another blood sample from the mother may be required.

This will be processed in the laboratory at no extra charge.

What is the process?

Once you have taken an independent personal decision that you want to have the NIPT prenatal test performed, you will be asked to sign a consent form and your blood sample can be taken from a vein in your arm along with a brief scan to confirm dates/viability. 

Who carries out the analysis of the test?

We will send your blood sample along with your personal information (including name, date of birth, gestational age) to The Doctors Laboratory based in London.

Do I need to have any other tests?

The NIPT prenatal test does not provide information on other rare chromosomal abnormalities. If the ultrasound scan shows a high nuchal translucency or other major physical defects such as brain abnormalities, heart abnormalities, the risk for some rare chromosomal defects may be high. In such cases, you may choose to have a CVS or an amniocentesis.


The NIPT prenatal test does not provide information on other physical defects such spina bifida, or information on fetal growth. It is therefore advisable that you have all the usual ultrasound scans during your pregnancy

Do I get any other information from the test?

If you wish, you can choose to know the baby's Gender from the blood test - as the lab can look at the Sex chromosomes if requested for no extra charge.


If you are expecting twins and you wish to know the Gender, we can ask for this to be assessed. If the result comes back as 'FEMALE' then both twins are female. If the result comes back as 'MALE' then either one or both twins are male.

The TDL NIPT Blood Test : from 10 weeks and 3 days onwards: £399

The TDL Test includes the following:

  • 30 minute appointment

  • Accurate results down to 4% fetal fraction

  • Dating/viability Scan

  • 4 black and white prints of baby

  • Report

  • Digital images: stills and short cine loops sent on link to your phone


The results will be ready in approximately 3-4 working days and the results are normally sent by email. Any unusual findings will be discussed with you and our Clinical Director


The IONA NIPT blood test : From 10 weeks and 3 days onwards £399.00

The IONA Test includes the following:

  • 30 minute appointment

  • Dating/viability Scan (brief, not chargeable)

  • 4 black and white prints of baby

  • Report

  • Accurate results down to 2% fetal fraction : reduced failure rate

  • The results will be ready in approximately 2- 5 working days and the results are normally sent by email. Any unusual findings will be discussed with you and our Clinical Director

The IONA® test estimates the risk that a fetus is affected with Down’s syndrome (Trisomy 21), Edwards’ syndrome (Trisomy 18) or Patau’s syndrome (Trisomy 13) by analysing placental cell-free DNA (cfDNA) isolated from a sample of the mothers’ blood. 

In each of these syndromes the cfDNA will include an extra copy of the chromosome concerned (e.g. in Down’s syndrome three copies of chromosome 21 are found rather than the two expected to be found in an unaffected fetus). A small blood sample (10ml) is taken for analysis by Whole Genome Sequencing. 

The IONA® test is developed and performed by Yourgene Health, based in Manchester, UK and it is also known as the SAFE test offered by the NHS for high risk pregnancies.

During pregnancy, the placenta leaks cell-free DNA which circulates in the maternal bloodstream. As a result, a maternal blood sample contains a mixture of fetal and maternal circulating DNA. 

The IONA® test directly measures the amount of cell-free DNA and can detect small changes in the DNA ratio between the maternal and cell-free DNA when a fetal trisomy 21, 18 or 13 is present. The IONA® test has an accuracy rate of >99%. 

In dichorionic twins, scientific publications suggest, that the test sensitivity is reduced from >99% to about 95%. In the case of a high-risk result, the screening test cannot determine which twin is affected and further testing would be required. 

The IONA® test is a screening test and all high-risk results should be confirmed by a follow-up invasive procedure. If fetal sex determination is requested, the accuracy is greater than 99%. A “sex determination failure” result may be reported if there is insufficient data to support the sex determination analysis. A “sex determination failure“ does not impact the trisomy result.

Further details:

You can have the IONA® test if you are: At least 10 weeks pregnant, carrying a singleton or a twin pregnancy and became pregnant naturally or through IVF, donor egg or surrogate pregnancy.


The test is not suitable if:

• You are a recipient of an organ transplant

• You have received any treatment involving the transfusion of heterologous cells in the last 12 months, for example a white cell blood transfusion or stem cell therapy,

• You have cancer,

• You carry a chromosomal imbalance


While the results of the IONA® test are highly accurate, discordant results may occur due to conditions affecting the pregnancy that you are unaware of such as placental or fetal mosaicism for a trisomy or a vanishing twin (If you are aware of any of these conditions, please indicate this on the test request form).


The IONA® test is also not suitable for expectant mothers with complete or partial monosomy X (Turner syndrome). If a sample is received with this condition and generates a result indicative of monosomy X then the healthcare professional will be informed that a repeat test is not recommended for this reason.

Early pregnancy: Panorama Test from Natera 

We are pleased to offer our patients an additional option for screening in Early pregnancy:

Panorama test from Natera which has the lowest quoted failure rate of 1.4% and it is from 9 weeks

There are 2 options :


1. The Panorama Basic NIPT  Panel for  T21,T18 and T13 including optional Gender £400

2. Panorama full Microdeletion Extended NIPT Panel for T21,T18 and T13 including optional Gender,Triploidy, Monosomy X, 22q11.2, 1p36, Angelman Syndrome,Cri-du-Chat syndrome, Prader-Willi syndrome £520 

Microdeletions present the biggest challenge in accurate detection.

The data below shows all cases of microdeletion listed are detected but that there is a high false positive rate : requiring further testing to confirm. Patients should consider this possible false positive outcome carefully and weigh up the pros and cons of having the test. 

panorama baby scan studio marlow

What are microdeletions and which ones does Panorama screen for?
A small, missing (or “deleted”) piece of a chromosome is called a microdeletion.


Unlike Down syndrome, which occurs more frequently in mothers who are 35 and older, microdeletions occur in pregnancies at the same rate for mothers of any age.

Microdeletions are very rare 

1:15,000 to 1:50,000 live-born infants Cri du Chat

1 in 12,000 to 20,000 Angelman 

1 in 10,000-30,000 Prader Willi

1/5000 and 1/10,000 IP36 deletion

In many cases, there are no obvious ultrasound abnormalities that would suggest the baby has a microdeletion. While many microdeletions have little impact on a child’s health and life, there are some that can cause intellectual disabilities and birth defects.

The Panorama Tests include the following:

  • 30-minute appointment

  • Accurate results down to 1.4% fetal fraction

  • Dating/viability Scan (not chargeable)

  • 4 black and white prints of baby

  • Report

  • Digital images: stills and short cine loops sent as a link to your phone

  • Discussion with a geneticist in the event of a positive result 

The Panorama Extended panel screens additionally for 5 microdeletions, all of which can be
associated with serious health issues:

• 22q11.2 deletion syndrome (also called DiGeorge syndrome): 

Babies born with 22q11.2 deletion syndrome often have heart defects, low blood calcium levels, immune system problems, and mild-to-moderate intellectual disability. They may also have kidney problems, feeding problems, and/or seizures.
• 1p36 deletion syndrome:
Babies born with 1p36 deletion syndrome have weak muscle tone, heart and other birth defects, intellectual disabilities, hearing loss, and behavior problems. Roughly half of these babies will also have seizures.
• Angelman syndrome:
Babies born with Angelman syndrome often have delayed milestones (like sitting, crawling, and walking), seizures, and problems with balance and walking. They also have severe intellectual disability, and most do not develop speech.
• Cri-du-chat syndrome (also called 5p minus):
Babies born with Cri-du-chat syndrome typically have low birth weight, small head size, and decreased muscle tone. Feeding and breathing difficulties are also common.
They also have moderate-to-severe intellectual disability.

• Prader-Willi syndrome:
Babies born with Prader-Willi syndrome have low muscle tone and problems with feeding and gaining weight. They also have an intellectual disability. As children and adults, they may develop an over-eating disorder resulting in obesity-related medical problems.


Blood Taking Services

We are able to take blood samples weekly from our clinic in Marlow by appointment only. Call 01628 486264 to make an enquiry or to book. Results can be emailed for convenience. Please call for a more comprehensive list of tests available.


Here is a list of the commonly requested samples:

Please note Laboratory processing times quoted below are from

when the sample reaches the laboratory.


  • Phlebotomy Service Charge • £45.00

  • AMH • £179.80 • 2 days

  • B12 and Red Cell Folate • £154.42 • 2 days

  • Beta HCG (Quantative) • £84.10 • 4 hours

  • CA125 • £174.72 • 4 hours

  • Female Hormone Profile (LH, FSH, Prolactin, Oestradiol) • £206.62

  • Full Blood count • £67.42 • 4 hours

  • FSH • £75.40 • 4 hours (on day 3 of cycle)

  • LH (Luteinising Hormone) • £75.40 • 4 hours

  • Oestradiol • £75.40 • 4 hours

  • Menopause Profile • £206.62 • 4 hours

  • Polycystic Ovary Syndrome Profile • £798.22 • 5 days

  • Progesterone • £75.40 • 4 hours

  • Prolactin • £75.40 • 4 hours

  • Rubella Antibody £77.58 • 4 hours

  • TSH  • £75.40


bottom of page