As non-invasive prenatal testing (NIPT) becomes more advanced, questions of informed consent, accuracy and ethical concerns have become more complicated for clinicians, and more distressing for parents, according to an article published in the MJA.

Lead author, Dr Joseph Thomas, a senior specialist in maternal-fetal medicine at Mater Health Services in Brisbane, told HealthTimes that “ordinarily, pregnant mothers have many anxieties to deal with.”

“When a result – even if it is from a screening test – comes back as high risk, maternal anxiety for the welfare of the unborn baby increases immensely.”

“I see many pregnant women in the consultation room who are in distress from the results that have been given to them without much explanation.”

“One invariably needs to perform invasive testing to confirm the diagnosis which is most often false positive”, Dr Thomas said.

NIPT testing as a screening for the common trisomies has good sensitivity with low false positive rates. As technology improved, the tests have been able to detect far more conditions than the common trisomies. Companies using targeted technology introduced various conditions with low incidence to the screening panels.

“This resulted in lower sensitivity and higher false positive rates. Some tests used technology which sequenced the whole human genome (WGS), albeit at a low resolution which also added to the abnormalities that could be detected.”

“Moreover, it is important to understand that NIPT tests placental DNA and not fetal DNA. All of this has added to the predicament that we are in now.”

Compounding the complexity of advancing technology are evolving societal expectations, as well as the desire from parents to have reassurance and certainty about their child.

“The practice of medicine has also changed over time with the expectation that all available tests will be offered. Technology needs to be tested and applied wisely.”

The authors of the article identified several ethical concerns when it came to the expansion of NIPT testing. These included:

• The challenges in providing adequate information arising from the complexity of the tests – it is the understanding of information that is important, not merely that a person was given the legally required information.
• The risk of power imbalances and normalisation of testing, whereby a patient simply agrees because ‘doctor knows best’ and, second, the impression that NIPT is a normal part of care, and therefore would be ‘foolish’ to reject.
• The problem of screening for ‘normality’ and genetic reductionism – just because a genetic anomaly can be identified does not necessarily mean that it would be phenotypically expressed; similarly, detection of genes associated with adult onset disease does not necessarily equate to disease.
• The doctor’s responsibility in determining which NIPT test is clinically indicated – screening should be recommended or chosen only if there is likely to be a proportionate benefit, and there is no disproportionate burden.

Dr Thomas added that it was important to note that most professional colleges including RANZCOG  do not recommend routine population based genome wide chromosome abnormality and microdeletion syndromes (extended panels).

“This recommendation needs to be considered by all practitioners”, he said.

When it comes to reducing the burden of unnecessary testing, addressing communication gaps between clinician and patient was essential – and time and awareness are ongoing roadblocks.

“GPs are very busy and have limited time for a consultation, and invariably may not have all the information about the technology involved and the statistics for each of the conditions screened for.”

“Most laboratories offer some information in brochures and in a tabular format. Invariably, there is some form of consenting that occurs, but our concern is that most often this is done to complete a formality.”

“This does not necessarily ensure that the mothers understand what their choices are and what the likely results would be”, Dr Thomas said.

“What we have suggested in the article is that genuine shared decision making models that empower pregnant mother's autonomy need to be developed”

“In addition, decision tools and algorithms that incorporate the mothers personal values need to be developed and used as appropriate by the primary care providers.”

“I would recommend that the standard NIPT test be performed after a 11-13 scan, ensuring fetal viability and that there are no major structural abnormalities detected. Being placental DNA, a low risk result could be obtained even when the fetus is not alive.”

Furthermore, the Dr Thomas and his co-authors emphases that higher resolution WGS NIPT should only be used for research purposes until there is robust data regarding its clinical utility.