国际战略投资集团（International Strategy and Investing Group）的医疗分析师兼常务副董事维杰•库玛尔说：“NIPT只需要取一滴血样。一旦用NIPT这种简单的技术取代了羊水穿刺等技术，人们无疑就会选择它。但是接下来就是成本的问题了。考虑到目前的医疗环境，这种讨论会变得更艰难。”
Every year, the U.S. welcomes 4 million new babies into the world, the result of roughly 4 million pregnancies that in large part go through the same battery of prenatal health checks 4 million times: analyses of the mother's blood and urine, of the mother's blood pressure, of the mother's weight, of the mother's blood sugar -- even of the mother's genetic makeup if she's deemed a risk for certain inheritable disorders. Ultrasound imaging being the obvious exception, doctors generally measure an unborn baby's health via the mother -- a kind of science by proxy that offers only a rough approximation of the baby's developmental health.
But if parents could know more about their child's health before birth, wouldn't they want to? And if a bounty of health information -- even the unborn child's entire genome and all the data contained therein -- could be accessed via nothing more than a simple blood draw from the mother, wouldn't parents want to have that option? A handful of medical diagnostics companies think so, and a new generation of non-invasive prenatal tests (NIPT) they have brought to market over the past couple of years have positioned them to completely transform the way clinicians perform routine prenatal care -- a full 4 million times annually in the U.S. alone.
NIPT technology rests on the fairly recent discovery that a pregnant mother's blood is practically swimming with fragments of her baby's DNA, deposited there as cells from the placenta die and break down. This cell-free DNA -- so named because it is not contained within the nucleus of a complete fetal cell, but rather floats free in the mother's bloodstream -- can be identified and isolated from the mother's own DNA (it turns out cell-free fetal DNA can make up as much as 20% of the free-floating DNA in a pregnant mother's circulatory system). There are other ways to access fetal DNA of course -- Amniocentesis for instance, or the more accurate chorionic villus sampling (or CVS) test -- but these require a physical incursion into the neighborhood of the fetus itself (usually via a long needle or tube) which ups the risk of miscarriage and pregnancy-complicating infections. That's the beauty of NIPT: A sample of maternal blood, a simple blood draw, is all that's needed to access the fetal genome and all the chromosomal information it contains.
When cell-free DNA was discovered about 15 years ago, the science of genetics was not yet far enough along to make much practical use of it, but with the rapid advancement of genetic science over the past decade that's changed. Non-invasive tests can now piece together entire fetal genomes and mine that genetic information for indicators of various disorders and abnormalities that can lead to health problems later on -- things like sex chromosome abnormalities, Down syndrome, and a host of other developmental disorders. Initial trials have shown the tests to be so reliable that executives at more than one company vying for the lead in the nascent NIPT space -- companies that include Verinata (owned by Illumina (ILMN)), Sequenom (SQNM), Natera, Ariosa Diagnostics, and Ravgen -- believe their tests will become a standard, routine part of prenatal care in the next two or three years.
"When you offset something like amniocentesis against NIPT -- which is as simple as taking a blood sample -- it becomes a no-brainer," says Vijay Kumar, a health care analyst and associate managing director at International Strategy and Investing Group. "But then the question becomes cost, and given the current health care environment it becomes a much tougher discussion."
Indeed, it's cost more so than science holding NIPT testing back at this point. The tests remain relatively expensive, around $800 at the low end, and just less than $3,000 for the more expensive screening methods. Ongoing litigation between Sequenom and two other players in the space -- Natera and Ariosa Diagnostics -- has created some confusion as to who really owns what technology (not to mention some increased expense for all parties). And the technology is so new that insurers, though cognizant of the potential preventative health benefits of NIPT, have not yet determined exactly whether or how they will reimburse for the tests.