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Tests in Pregnancy

Non-invasive Prenatal Testing (NIPT)

Noninvasive Prenatal Testing is currently the most advanced non-invasive pregnancy screening available for parents who would like to determine if their baby has a low or high probability of having the conditions Down’s syndrome, Edwards’ syndrome or Patau’s syndrome. The test is performed via The Doctors Laboratory (TDL) in London. Formally known as the Harmony Test, TDL have replaced the Harmony test with Veriseq NIPT by Illumina.

The TDL Veriseq v2 by Illumina test is available from as early as 10 weeks of pregnancy, for early screening before the NHS Nuchal Translucency scan.


How Does It Work?

A blood sample taken from the mother from 10 weeks of pregnancy onwards can be analyzed for cell free DNA (cfDNA), which represents a sample of the fetal-placental DNA. There is no increased miscarriage risk to your baby from having this simple, safe maternal blood test.

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.

If requested by your doctor, NIPT can also screen for Turner syndrome, Klinefelter syndrome and other sex chromosome anomalies (Triple X syndrome and XYY syndrome). You also have the option to determine the sex of your baby.

The NIPT is a screening test and will not provide you with a definitive genetic diagnosis. Results will be reported as either high or low probability. A definitive diagnosis of the baby will require analysis of the amniotic fluid (Amniocentesis) or placental tissue (chorionic Villus Sampling CVS).


How Accurate is NIPT?


The Verisq v2 is more accurate than the first trimester maternal serum screening and ultrasound scan (Combined/quadruple test) offered on the NHS.

NIPT screening for trisomy 21, 18 and 13 – the most common chromosome conditions – provides the highest accuracy. Screening for other syndromes or for fetal sex is reasonably reliable; however, it is not as accurate as the screening for trisomy 21, 18 and 13.

The test can be performed in twin, singleton, IVF and surrogate pregnancies. A full pretest questionnaire will be completed prior to the test.

Your results will be ready within 7 days.

What happens if I get a high probability result?

If your result shows a high probability for any of the chromosomal conditions, we will discuss you’re results and you will have the opportunity to ask questions.  A referral will be made to your local NHS screening team or a private obstetrician/fetal medicine specialist if you wish to discuss and arrange further diagnostic testing.  


For further information:

Down's syndrome - NHS ( 

Non-invasive Prenatal Testing / £395

Group B Streptococcus - Enriched Culture Medium (ECM) Testing

Group B Streptococcus (GBS) is one of the many bacteria that normally live in our bodies and which usually cause no harm. It is carried in the vagina and rectum of 20 – 40 % of women in the UK. GBS is not a sexually transmitted disease and most women carrying GBS will have no symptoms. Carrying GBS is not harmful to you, but it can affect your baby around the time of birth. GBS can occasionally cause serious infection in newborn babies and, very rarely, during pregnancy and before labour.

The UK National Screening Committee does not recommend testing all pregnant women for GBS carriage and at present routine screening is not offered on the NHS.

If you carry GBS, most of the time your baby will be born safely and will not develop an infection. However, it can in rare circumstances cause serious infections such as sepsis, pneumonia or meningitis.

In the UK, up to two-thirds of GBS infection in babies are of early onset (showing within the first 6 days of life). Early-onset group B Strep infections occur in around 1 in every 1,750 babies in the UK and Ireland. Most early-onset GBS infections are preventable.

The risk of your baby becoming unwell with GBS infection is increased if your baby is born preterm, if you have a temperature while you are in labour, or if your waters break before you go into labour. If your newborn baby develops signs of GBS infection, they should be treated with antibiotics straight away.

Carrying Group B Strep has no symptoms, so testing is the only way to find out if you are carrying the bacteria. A group B Strep test is simple, safe and effective. A vaginal and rectal swab is taken and sent to The Doctors Laboratory in London. The results will be available to you within 5 days.

When can you have the test?


GBS is a transient bacterium, meaning it can come and go. You can test earlier in pregnancy, but the test result is not as reliable at predicting what your carriage status will be (positive or negative) when you give birth.

Research has shown that if performed within 5 weeks of birth then a negative result is 96 % predictive that you would not be carrying group B strep at birth. A positive result is 87% predictive that you would be carrying group B strep at birth.

Most women would aim to test within the last 5 weeks before they are due to give birth (between 35-37 weeks’ of pregnancy). The test can also be done later, but the chance increases that the baby will arrive before the test result does.

If you have a history of going into labour early or are expecting twins (or more), you may want to take this into account when arranging your group B Strep test.

What happens if I test GBS Positive?


Firstly, please don’t worry! Your results will be discussed with you, and you will have opportunity to ask questions.

Carrying GBS does not pose a health risk or cause symptoms in the person carrying the bacteria. If you are known to carry group B Strep in your current pregnancy then you will be offered antibiotics from onset of labour which will minimize the risk of your newborn baby developing a group B Strep infection.

For more information -

Group B Strep ECM Test / £95

Private Blood Tests in Pregnancy

Priced Individually

Screening blood tests will be offered to you in pregnancy by the NHS and are usually arranged before 12 weeks. Some women prefer to have these tests privately so that they can be performed earlier in the pregnancy and receive the results faster. Testing for the following can be arranged via The Doctors Laboratory in London.

  • Full Blood Count

  • Blood Group and Rhesus

  • Antibodies

  • HIV Status

  • Hepatitis B Status

  • Syphilis

  • Sickle Cell, Thalassemia and other Haemoglobin disorders

  • Rubella status

  • Varicella Zoster (Chicken Pox Immunity Status)


In the event that any of the tests show an abnormality, a referral to your GP or local NHS maternity team will be offered to discuss further testing or treatment if necessary.

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