Tag: NIPT

Harmony NIPT Test – Yesterday’s News

Written by London Pregnancy Clinic on 3. September 2023. Posted in Blog, NIPT, NIPT, Ultrasound. No Comments on Harmony NIPT Test – Yesterday’s News

Harmony NIPT Test – Yesterday’s News

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End of an era…

TDL Genetics (The Doctor’s Laboratory) have announced last week that it will cease providing Harmony NIPT in its UK laboratories. TDL started providing Harmony Non-Invasive Prenatal Screening back in 2013.

Harmony NIPT, which was introduced by Ariosa Diagnostics in 2013, was for a long time a gold standard in Non-Invasive Prenatal Testing. The company was later acquired by the Swiss giant Roche Holdings, which was very successful at marketing the test and in many countries, the brand name ‘Harmony Test’ has become synonymous with ‘NIPT’. In the UK, this was particularly the case as it was one of the first NIPT tests to be approved by the NHS, and it offered in many state hospitals.

NIPT was first introduced by the now-defunct Sequenom, using the brand name MaterniT21Plus™, which was approved by the FDA in 2011. Harmony Test pioneered a new method of NIPT screening using a different cfDNA sequencing method. Harmony NIPT exhibited excellent clinical performance data at the time, helping it solidify its status as the preferred NIPT test by many healthcare professionals.

The future looks good!

In the past 10 years, NIPT has become a heavily researched space, meaning that many companies have raced to create their own NIPT test using a host of advanced technologies. A couple of such competitors are Natera’s ‘Panorama Test’ and Erofins’ ‘PrenatalSAFE Test’. This increased level of competition meant that patients could now benefit from much more advanced tests for chromosomal anomalies such as Down’s syndrome and screening for rare genetic diseases.

In this time, Harmony NIPT has fallen behind in terms of its technology versus the new tests. Furthermore, the equipment used for the test has become dated and as such many of the tests performed by TDL ended up failing to produce conclusive results due to ‘quality control issues’. These so-called ‘no-call’ results, or failure of one of the testing tubes, have become so prevalent with the samples we sent to TDL that we raised our first of many complaints with TDL back in 2021. Unfortunately, these lab challenges caused significant emotional distress for our expectant parents and frustration for our clinic’s team.

NIPT at London Pregnancy Clinic

In light of these developments, at London Pregnancy Clinic, being one of the top NIPT providers in the UK and leading international experts in fetal medicine, we set on the path of finding the best alternative NIPT. We were one of the first clinics in the UK to offer the advanced NIPT test from Invitae back in 2021. Since then, we have worked with many NIPT brands and have helped hundreds of patients navigate the best NIPT choice for them.

Our clinical team has spent months interviewing the laboratory teams of all major NIPT providers as well as auditing their clinical performance. We are now the leading provider of NIPT in London, and we feel responsible for our patients’ pathway to choose the best option in the market at every given time. We have the experience of providing the Harmony NIPT and other NIPTs, and the expertise to distinguish the performance of each test in the market. We do not offer any NIPT without thoroughly reviewing its characteristics and clinical data.

As of TDL’s new NIPT option, namely the Illumina VeriSeq NIPT, we are still waiting for the lab to send us clinical performance data and set up an interview with the lab team before we are able to offer the test to our patients. For now, we have many questions for the lab given the poor quality of performance of the Harmony NIPT in terms of no-call results which was much higher than Roche’s advertised levels from our experience. In the meantime, we are confident that our current menu of NIPT tests is the latest and most advanced screening options in the market with similar turnaround times to TDL.

As always, we will keep reminding our patients that NIPT should be done alongside a complete examination of the fetal anatomy via an ultrasound scan. The NIPT marketing machine has helped raise awareness of certain chromosomal anomalies, in particular Down’s Syndrome. However, NIPT can give you a false sense of reassurance as it is useless in screening for structural anomalies (physical defects) representing more than 2/3 of known fetal abnormalities and can often be detected using ultrasound.

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Gynaecological Pelvic Scans: Importance, Procedure, and Diagnostics

Written by London Pregnancy Clinic on 7. August 2023. Posted in Blog, Gynaecology, Ultrasound. No Comments on Gynaecological Pelvic Scans: Importance, Procedure, and Diagnostics

In the realm of gynaecology, pelvic scans play a crucial role in maintaining women’s health. These essential imaging tests help visualise the organs within the female pelvic region, aiding the diagnosis of various conditions. This comprehensive blog post provides an in-depth understanding of gynaecological pelvic scans – their importance, procedure, potential risks, the conditions they can diagnose, their history, and the organs they help visualise.

Why Are Gynaecological Pelvic Scans Important?

Gynaecological pelvic scans provide detailed images of the female pelvic organs, including the uterus, ovaries, fallopian tubes, cervix, and bladder. This non-invasive procedure aids in the diagnosis and management of numerous conditions such as fibroids, ovarian cysts, endometriosis, pelvic inflammatory disease (PID), and even cancer.

This type of imaging allows medical professionals to identify abnormalities, track their progress, and evaluate the effectiveness of treatments. It’s also a vital tool for pregnancy management, helping to monitor foetal development, placental health, and diagnose ectopic pregnancies.

How are Gynaecological Pelvic Scans Performed?

Pelvic scans in gynaecology are typically performed through ultrasound technology. Ultrasounds work by emitting high-frequency sound waves that bounce off tissues and organs, creating echoes that are converted into real-time images.

There are two main types of gynaecological pelvic scans: transabdominal and transvaginal. The transabdominal scan is performed externally, with a probe moved over the lower abdomen. For a transvaginal scan, a specially designed probe is inserted into the vagina, providing closer, more detailed images of the pelvic organs.

Are There Any Risks? Are They Painful?

Gynaecological pelvic scans are generally safe, non-invasive procedures with minimal risk. Ultrasound technology does not involve radiation, making it safer than other imaging techniques.

In terms of discomfort, while some women might experience mild discomfort during a transvaginal scan, it’s typically not painful. The procedure is usually quick, and any discomfort tends to subside immediately after the scan.

Is There a Need for Preparation?

Preparation for a gynaecological pelvic scan may vary depending on the type of ultrasound. For a transabdominal scan, patients may be asked to drink water before the procedure to fill the bladder, which allows better visualisation of the pelvic organs. For a transvaginal scan, typically, no specific preparation is required.

Conditions Diagnosed by Gynaecological Pelvic Scans

Pelvic scans can diagnose a multitude of conditions, including:

Fibroids: Non-cancerous growths in the uterus, often appearing during childbearing years.
Ovarian cysts: Fluid-filled sacs in the ovary, usually harmless but occasionally requiring treatment.
Endometriosis: A condition where tissue similar to the lining of the uterus grows outside it, causing pain and potentially affecting fertility.
Pelvic Inflammatory Disease (PID): An infection of the female reproductive organs, often due to sexually transmitted bacteria.
Gynaecological cancers: Pelvic scans help detect and manage cancers of the cervix, uterus, and ovaries.

The History of Scans in Gynaecology

The use of ultrasound technology in gynaecology has evolved significantly since its first clinical application in the 1950s. The initial ‘A-mode’ ultrasounds, which provided one-dimensional information, evolved into ‘B-mode’ in the late 1950s, delivering two-dimensional images. The introduction of Doppler ultrasound in the 1970s brought colour to the images, providing information about blood flow. Today, we even have 3D and 4D ultrasounds, allowing for detailed three-dimensional imaging and real-time movement.

Organs Visualised by Gynaecological Pelvic Scans

Gynaecological pelvic scans offer comprehensive imaging of the female pelvic organs. This includes the uterus, ovaries, fallopian tubes, cervix, and bladder. Another type of scan that specifically focuses on the potency of the fallopian tubes is know as HyCoSy.

Unravelling Microdeletions: Their Causes, Risk Factors, Common Types, and Screening Methods

Written by London Pregnancy Clinic on 31. July 2023. Posted in Blog, NIPT, NIPT, Obstetrics, Ultrasound. No Comments on Unravelling Microdeletions: Their Causes, Risk Factors, Common Types, and Screening Methods

Microdeletions are a topic of extensive genetic research. These small deletions in the DNA sequence of a chromosome can have significant implications on an individual’s health. In this comprehensive blog post, we delve into the causes, risk factors, ten most common types of microdeletions, their prevalence, and the role of Non-Invasive Prenatal Testing (NIPT) in their detection.

What are Microdeletions?

Microdeletions are tiny losses of genetic material in the DNA sequence of a chromosome. These minute changes are typically undetectable under a standard microscope, hence the term ‘micro’. However, despite being minute, these deletions can lead to significant health and developmental problems, as they may disrupt several genes essential for growth and development.

Causes and Risk Factors

The exact cause of microdeletions remains unknown, and their occurrence seems largely spontaneous. They typically occur during the formation of reproductive cells or in early foetal development, resulting from a mistake in the cell’s DNA replication process.

In terms of risk factors, there’s no established link between microdeletions and parental age, ethnicity, or lifestyle. These changes can happen in any pregnancy, but familial history can increase the chances if a parent has a balanced translocation or an inherited microdeletion.

The Ten Most Common Microdeletion Syndromes

Here’s a list of ten of the most common microdeletion syndromes, along with their estimated prevalence:

Syndrome	Approximate Prevalence
1. DiGeorge Syndrome (22q11.2 deletion syndrome)	1 in 3,000 – 1 in 6,000
2. Williams Syndrome (7q11.23 deletion syndrome)	1 in 7,500 – 1 in 20,000
3. Prader-Willi Syndrome	1 in 10,000 – 1 in 25,000
4. Angelman Syndrome	1 in 10,000 – 1 in 20,000
5. Cri-du-chat Syndrome (5p- syndrome)	1 in 20,000 – 1 in 50,000
6. 1p36 Deletion Syndrome	1 in 5,000 – 1 in 10,000
7. Wolf-Hirschhorn Syndrome (4p- syndrome)	1 in 20,000 – 1 in 50,000
8. Smith-Magenis Syndrome (17p11.2 deletion syndrome)	1 in 15,000 – 1 in 25,000
9. Alagille Syndrome (20p12 deletion syndrome)	1 in 30,000 – 1 in 50,000
10. Rubinstein-Taybi Syndrome	1 in 100,000 – 1 in 125,000

Microdeletions, in general, occur in approximately 1 in every 1,000 births, making them a significant contributor to genetic disorders. Just to compare Down’s Syndrome, the most common chromosomal disorder affects approximately 1 in 1,000 to 1 in 1,100 live births worldwide. The frequency of Down’s Syndrome increases significantly with the mother’s age, particularly from 35 years onwards whereas microdeletions are believed to occur randomly.

Microdeletion Screening: The Role of NIPT

Screening for microdeletions has been revolutionised by advancements in genetic testing, particularly with the introduction of Non-Invasive Prenatal Testing (NIPT). This screening test, performed from the 10th week of pregnancy, analyses cell-free DNA in the maternal blood to identify common chromosomal abnormalities and microdeletions. NIPT poses no risk to the foetus and offers a safer alternative to invasive diagnostic procedures.

Though NIPT has high accuracy rates, it’s crucial to understand that a ‘positive’ result indicates an increased risk, not a definitive diagnosis. Positive NIPT results should always be confirmed through diagnostic tests such as amniocentesis or chorionic villus sampling (CVS).

There are a number of NIPT providers who offer screening for microdeletions, such as Panorama NIPT, Unity NIPT and PrenatalSAFE.

Conclusion

While the world of microdeletions might seem complex, understanding them is crucial to advancing our knowledge of genetic disorders. Early detection, made possible by advanced screening methods like NIPT, allows for better preparation and potential intervention. As research continues to evolve, we can hope for even more effective detection and management of these genetic changes, ultimately leading to improved healthcare and patient outcomes.

Remember, if you have any concerns or questions about genetic disorders or prenatal testing, it’s always advisable to consult with a healthcare professional who can provide tailored advice based on your individual circumstances.

DiGeorge Syndrome: Causes, Risk Factors, Screening and Prevalence

Written by London Pregnancy Clinic on 24. July 2023. Posted in Blog, NIPT, NIPT, Obstetrics, Ultrasound. No Comments on DiGeorge Syndrome: Causes, Risk Factors, Screening and Prevalence

DiGeorge Syndrome, also commonly known as 22q11.2 deletion syndrome (or simply 22q del,) is a complex and multifaceted disorder that many people may not be aware of. This blog post aims to shed light on the causes and risk factors of DiGeorge Syndrome, discuss screening options such as Non-Invasive Prenatal Testing (NIPT), and compare its prevalence with conditions such as Down’s Syndrome.

Understanding DiGeorge Syndrome (22Q DEL)

DiGeorge Syndrome is a chromosomal disorder caused by the deletion of a small piece of chromosome 22, specifically on the q11.2 region. The deletion happens spontaneously during the formation of reproductive cells or in early fetal development. The primary cause of 22q del is unknown, and it typically isn’t inherited from the parents.

The syndrome is characterised by a wide range of potential symptoms, including heart defects, certain facial features, and learning difficulties.problems with immune system and other abnormalities. Unfortunately, 22q del syndrome is also associated with learning difficulties and psychiatric or behavioural problems like autism and schizophrenia. Due to its complex nature, different individuals affected may present a different set of symptoms, making it a highly variable condition.

Risk Factors

Although the exact cause of the chromosomal deletion leading to DiGeorge Syndrome is unknown, it’s not typically associated with the age of the parent, unlike some other genetic disorders. The occurrence appears to be mostly random, which means that all pregnancies, irrespective of familial history, have a minimal but real risk.

Screening for DiGeorge Syndrome: The Role of NIPT

Non-Invasive Prenatal Testing (NIPT) has emerged as an invaluable tool for the early detection of several genetic disorders, including DiGeorge Syndrome. NIPT analyses cell-free DNA in the maternal blood to detect common chromosomal abnormalities. This test can be performed from the 10th week of pregnancy and poses no risk to the fetus.

While NIPT is highly accurate for detecting common trisomies like Down’s Syndrome (trisomy 21), Edwards’ syndrome (trisomy 18), and Patau’s syndrome (trisomy 13), it’s also valuable for identifying deletions like those causing DiGeorge Syndrome. It’s essential to remember, however, that a positive NIPT result for DiGeorge syndrome should be confirmed with diagnostic tests like amniocentesis or chorionic villus sampling (CVS) for a definitive diagnosis.

Not all NIPT provider offer reliable screening for DiGeorge Syndrome. Recently, the Panorama AI NIPT demonstrated impressive clinical performance for screening Di George Syndrome, you can read more about the study here. In well-designed prospective study Panorama Test was able to detect more than 80% of the fetuses affected by 22q del, showing an outstanding 50% positive predicted value.

Prevalence of DiGeorge Syndrome vs Down’s Syndrome

DiGeorge Syndrome is considered one of the most common genetic syndromes, second only to Down’s Syndrome. In the general population, it’s estimated to affect between 1 in 2,000 to 1 in 4,000 live births. Younger women have the same chance to deliver baby with 22q del as older ones.

In contrast, Down’s Syndrome, the most common chromosomal disorder, has a higher prevalence rate, affecting approximately 1 in 1,000 to 1 in 1,100 live births worldwide. The frequency of Down’s Syndrome increases significantly with the mother’s age, particularly from 35 years onwards.

Conclusion

Understanding and awareness of genetic disorders like DiGeorge Syndrome are crucial, not just for healthcare professionals, but for the general public too. While DiGeorge Syndrome is less common than Down’s Syndrome, it still represents a significant proportion of genetic disorders. By employing advanced screening methods such as NIPT, early detection and management of these conditions can be made possible.

Remember, if you have concerns or questions about genetic disorders or prenatal testing, it’s always best to consult with a healthcare professional who can provide advice tailored to your individual circumstances.

Understanding The Statistics Behind NIPT (Non-Invasive Prenatal Testing)

Written by London Pregnancy Clinic on 14. July 2023. Posted in Blog, NIPT, NIPT, Obstetrics, Ultrasound. No Comments on Understanding The Statistics Behind NIPT (Non-Invasive Prenatal Testing)

Summary:

The best NIPT will be really good at detecting problems (high sensitivity) and correctly saying everything is fine (high specificity). It should hardly ever make mistakes by saying there’s a problem when there isn’t (low false positive) or missing a problem and saying everything is okay (low false negative). If the test says there’s an issue, it should be highly likely to be true (high positive predictive value). And if it says everything is fine, it should be trustworthy (high negative predictive value).

NIPT (non-invasive prenatal testing) is a type of genetic test used to screen for certain chromosomal abnormalities and genetic syndromes in a developing fetus. The test involves analyzing a sample of the mother’s blood to look for fragments of DNA from the fetus.

It’s good to know the statistical terms related to NIPT performance because they help you understand how accurate the test is and what the results mean. You might be wondering why it’s important to understand those “boring statistics” related to NIPT (non-invasive prenatal testing) performance, but trust us, it’s actually really helpful! Knowing these statistical terms can make a big difference in your pregnancy journey.

By understanding these terms, you can make informed choices about your prenatal care. If the test is really accurate, you might feel more confident in the results and decide not to have further tests. But if the test has limitations, you might want to consider additional testing to get more clarity. It’s all about making sure you have the information you need to make the best choices for you and your baby.

So, while statistics might seem boring at first, they play a vital role in your understanding of the test’s accuracy, interpretation of results, and decision-making process. Embracing these statistics can give you more confidence and peace of mind throughout your pregnancy journey.

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Please see below the most important statistical terms related to NIPT performance:

Sensitivity: This measures how good the test is at correctly identifying fetuses that have a chromosomal abnormality. A high sensitivity means that the test is good at detecting most cases of abnormality. For example, if a test has a sensitivity of 99%, it means that out of 100 fetuses with a chromosomal abnormality, the test correctly identifies 99 of them.
Specificity: This measures how good the test is at correctly identifying fetuses that do not have a chromosomal abnormality. A high specificity means that the test avoids identifying normal fetuses as abnormal. For example, if a test has a specificity of 99%, it means that out of 100 normal fetuses, the test correctly identifies 99 of them as normal.
Positive predictive value (PPV): This is the probability that a positive test result is a true positive. In other words, if the test comes back positive, the PPV measures the likelihood that the fetus actually has a chromosomal abnormality. For example, if a test has a PPV of 95%, it means that out of 100 positive test results, 95 of them are true positives.
Negative predictive value (NPV): This is the probability that a negative test result is a true negative. In other words, if the test comes back negative, the NPV measures the likelihood that the fetus does not have a chromosomal abnormality. For example, if a test has an NPV of 99%, it means that out of 100 negative test results, 99 of them are true negatives.
False positive rate (FPR): This measures how often the test gives a positive result for a normal fetus. A low FPR means the test is good at avoiding false positives. For example, if a test has an FPR of 1%, it means that out of 100 normal fetuses, the test gives a false positive result for only 1 of them.
False negative rate (FNR): This measures how often the test gives a negative result for an abnormal fetus. A low FNR means the test is good at avoiding false negatives. For example, if a test has an FNR of 1%, it means that out of 100 fetuses with a chromosomal abnormality, the test gives a false negative result for only 1 of them.

When we look at how well NIPT works, it’s important to consider a bunch of statistics together. A good test will have high sensitivity, high specificity, low false positive and false negative rates, and high PPV and NPV.

Just remember, the performance of NIPT can vary depending on the specific test and the group of people being tested. So, when you get the results, make sure to understand how good that particular test is.

Considering all these statistics helps us know how reliable the test is and what the results mean for you and your baby. It’s about making informed choices and getting the best care possible.

Learn more about the NIPT providers we use:

Harmony Test by Roche: https://harmonytest.roche.com/global/en/home.html

Panorama Test by Natera: https://www.natera.com/womens-health/panorama-nipt-prenatal-screening/

PrenatalSAFE by Eurofins: https://www.eurofins.ie/biomnis/our-services/medical-testing/non-invasive-prenatal-test-nipt-prenatalsafe/

Unity Test by BillionToOne: https://unityscreen.com/

NIPT: Non-invasive Prenatal Testing

Written by London Pregnancy Clinic on 15. June 2020. Posted in Blog, NIPT.

NIPT (Non-invasive Prenatal Testing) is an optional blood test that can be performed in the first trimester from 10 weeks of pregnancy and is used to screen for some genetic conditions. Read more about NIPT:

How does NIPT work?

At City Ultrasound, we offer the Harmony Test, which is an extensively clinically validated type of NIPT. The Harmony Test is able to sensitively screen for:

Down Syndrome (Trisomy 21),
Trisomy 18,
Trisomy 13,
Fetal Sexing.

How does NIPT work?

Most of our genetic material (DNA) is contained within our cells; however, a small proportion of this circulates in our blood as cell-free DNA (cfDNA). When a woman is pregnant, the blood also contains cell-free DNA fragments from the placenta, which has a genetic make-up practically identical to that of the developing baby.

By taking a simple blood sample, the laboratory can isolate the cell-free DNA fragments and screen for risks associated with certain genetic conditions.

What can NIPT show me about my pregnancy?

At present, NIPT is an extremely sensitive test for Down’s Syndrome and it performs significantly better than the Combined Screening Test used by the NHS. However, it is important to understand that NIPT is a screening test—this means that it cannot give you a definitive diagnosis or 100% exclude any of the genetic conditions. Its purpose is to estimate whether the baby has an increased or decreased chance of the genetic conditions being tested for.

What are the limitations of NIPT?

As a screening test, NIPT can give an indication of your chance for these genetic conditions, but it cannot be used as a diagnostic tool—further tests would be needed for this. There are also instances where the test gives false-positive or false-negative results, which can give you a false sense of worry or security.

We, at City Ultrasound, strongly believe that the optimal method for checking the health of your baby during the first trimester includes the NIPT and ultrasound scanning (conducted by a specialist). More specifically, we believe that the combination of the Early Fetal Scan and NIPT is the ideal screening option. Of course, no screening program is 100% definitive, but this option allows for a detailed examination of the baby’s physical anatomy, such as the structure of the heart and brain (from the ultrasound), NIPT (as discussed above), as well as the assessment of Nuchal Translucency (NT), which examines the pocked of fluid behind the baby’s neck, giving us more information about the chances of different anomalies. This way we can offer the most information regarding all aspects of your baby’s health.

What’s next?

Normally, a “low chance” result from NIPT is very reassuring, as the test has a high negative predictive value (greater than 99%) for Down’s Syndrome.

As NIPT is not diagnostic, if a result was to suggest and increased chance of chromosomal anomaly, there would be an option to perform CVS (placental biopsy) or amniocentesis. While those are invasive and carry a small risk (0.5-1%) of miscarriage, these tests can give definitive results about the chromosomal abnormalities that may be present. Invasive tests are performed in specialist Fetal Medicine Units of hospitals. The decision to perform the invasive test is something that should be discussed with your healthcare team.