Non-Invasive Prenatal Tests - General Information

Non-invasive prenatal screening tests are offered in early pregnancy at The Medical Chambers Kensington in London. These tests allow information about a baby's chromosomes to be obtained using a blood sample from the mother, providing a risk assessment of some developmental abnormalities affecting the baby. These tests are carried out by leading experts in the field of foetal ultrasound, in a discrete and supportive environment, and results are delivered without delay.

Non-invasive prenatal testing (NIPT), carries no risk to mother or baby. Until recently when the risk of abnormal development was deemed to be high, the most reliable way to gather definitive information about a baby's genetic makeup was to use an amniocentesis: this procedure involves introducing a very fine needle through the mother's abdominal wall and into the amniotic fluid around the baby to withdraw some fluid and allow analysis of the cells. Although an amniocentesis produces clear results, it does carry a small risk of miscarriage; non-invasive testing is therefore very welcome.

The most widely known condition resulting from genetic abnormality is Down syndrome. This is one of a range conditions known as 'trisomy' (where there are three copies of a chromosome instead of the usual two) that result in physical defects, some of which may be life threatening, and can be tested for during pregnancy. More information is on the website on our page about congenital conditions.


Why chose to have a prenatal blood test?

You may request one of these tests if you wish to have reassurance that everything is developing normally. Typically, however, a chromosomal test in pregnancy is requested where a significant risk of chromosomal abnormality has been calculated. This will be based on consideration of maternal age, personal medical history, family or genetic history, and results of an early pregnancy scan. We recommend you discuss your personal situation with your doctor or prenatal specialist. Chromosomal analysis during pregnancy is not routine but as a private clinic we are here to meet your needs, whatever your personal or family background. We do not require referral from your doctor.

The NIPT is used to detect Trisomy 21 (Down Syndrome); Trisomy 18 (Edwards Syndrome) and Trisomy 13 (Patau Syndrome). You can learn more about these conditions by clicking on the link below.

Other congenital conditions and physical or developmental abnormalities are not detected by the Harmony or MaterniT21 PLUS tests; for these ultrasound scans are still the primary source of diagnostic screening.


Can I have a non-invasive prenatal blood test without a scan at The Medical Chambers Kensington?

Our gold standard is a 12 week nuchal translucency scan along with the choice of one of these three tests. Dr David Nyberg pioneered this type of non-invasive prenatal test in the United States and is one over very few specialists offering them in the UK. His recommendation is that even MaterniT21 PLUS, the most comprehensive test currently available, should be taken alongside the 12 week scan - it does not replace this scan, but it does support it and provide additional information.

In some cases we will offer a non-invasive prenatal blood test without a scan carried out at The Medical Chambers Kensington. When you call us, we will arrange for you to talk to Dr Nyberg to establish whether we can offer you this option and to help you choose the test best suited to your circumstances. Dr Nyberg will also liaise with you personally when he receives your test results.


To learn more about this option please contact Dr Isabelle Granger-Cohet on 07948 432315 or email her at

Learn more about the MaterniT21 PLUS Prenatal Test.

Learn more about the MaterniT GENOME Prenatal Test.

Learn more about the Harmony Prenatal Test in pregnancy.


Here you can learn more about congenital conditions related to chromosome abnormalities.