The Advertising Standards Agency recently published an enforcement notice regarding adverts for NIPT. You can read about this here. It is very important to be aware of the positive predictive value of NIPT (PPV). This is the probability that a high chance result is correct.
NIPT has a high detection rate especially for Down’s syndrome, meaning that the vast majority of cases would be picked up by the test. However the term “detection rate” (or sensitivity) should not be confused with “accuracy”, a broader term that covers all aspects of test statistics including both the detection rate of a test and also it’s PPV; (again the chance a positive or high chance test result is correct.) The PPV of NIPT varies and depends upon the condition being tested for and on your background risk. Factors such as age and any NHS screening results or scan findings affect the PPV. Because the PPV is low for some groups of women (e.g. those with a low background risk) NIPT is not considered to be diagnostic. This means that any high chance result should be investigated further with an invasive test such as amniocentesis or chorionic villus sample before any irreversible decisions are made about continuation of the pregnancy.
We have strived to ensure the information we give you about NIPT is balanced as it is an essential part of consent for the test. You can read about harmony on our web-page here. When you come for your test it is a 30 minute long appointment allowing plenty of time for all of your questions to be answered. We have a detailed information leaflet we give you and written consent is taken. If we cannot answer a question of yours we can consult our in house Consultant Obstetrician or direct you towards other information sources.