Prenatal genetic testing is an invaluable tool for identifying potential chromosomal abnormalities before birth. The tests are typically offered to women who fall into the “at-risk” category – which includes:
- Women over 35
- Women who have had a positive serum test (or an ultrasound suggestive of a chromosomal condition)
- Those with a family history of chromosomal abnormalities.
Though extremely useful for medical staff, the results of these tests may not always be clear-cut. The Perinatal Quality Foundation – an Oklahoma-based non-profit aimed at improving the quality of obstetric care through educational programs – is collaborating with lab solutions provider Quest Diagnostics to develop a program designed to give the public a more thorough understanding of what their prenatal noninvasive test (or PNIT) results really mean.
The program aims to help women and their partners make more informed decisions following a test – as well as to create a registry within which women across the country can log the results of their genetic tests, giving researchers a resource to confirm test accuracy.
Understanding what “positive” really means
A very prevalent misconception among women who have undergone prenatal genetic testing is that the results of a cell-free DNA test are 100% conclusive – that if a fetus tests positive for trisomy 21 via a cell-free test, then the baby will certainly be born with Down syndrome. But the results are not as clear-cut as that – cell-free DNA testing is only intended as a “first step” to assess risk. A positive prenatal genetic test may not be definitive, and the next course of action should be for the patient to undergo more invasive tests to confirm whether her child will be affected.
Clinicians don’t advise making decisions about a pregnancy based off the results of a prenatal genetic test. Lab test manufacturers have been very transparent about this – for example, test manufacturer Sequenom, producer of the MaterniT21 PLUS test, lists clearly on their website that a patient with a positive result “should be referred for genetic counseling and offered invasive prenatal diagnosis for confirmation of test results.” But the message doesn’t always make it to pregnant women who are offered a PNIT.
Researching results through a collaborative registry
The other focus of the Perinatal Quality Foundation’s initiative is to create an online registry, accessible by women who have undergone prenatal noninvasive testing, where patients can report their results. Researchers can use the data to assess the accuracy of prenatal testing by assessing the percentage of positive PNIT tests whereby a more conclusive test was negative. The hope is that this data will help calm fears about positive results, as well as educate expectant mothers on the importance of seeking more invasive (and conclusive) testing before making any decisions.
PQF plans to develop educational tools and materials for the campaign, including a website and forum, for healthcare providers and patients alike. The registry will also feature support groups and resources helpful for women and couples concerned about their positive test results.