Details about the test which are awaiting authorization from the New York State Department of Health before it can be offered to Columbia patients and its performance was published in the New England Journal of Medicine.
Prenatal genetic testing are currently available, but they are expensive and take days to weeks to complete; this adds to the emotional and financial strain of fertility treatment and pregnancy and affects treatment options.
The STORK (Short-read Transpore Rapid Karyotyping) test, which may be performed at the point of care in a doctor’s office, provides results in less than two hours, and costs roughly 10% less to process a sample than existing tests. With a fraction of the time and expense of currently available clinical genetic testing, the new prenatal test created by researchers at Columbia University Fertility Center can detect whether a foetus or embryo has the proper number of chromosomes.
“We are developing the most advanced technologies to solve some of the most ancient of afflictions — infertility and pregnancy loss,” says study leader Zev Williams, MD, Ph.D., the Wendy D. Havens Associate Professor of Women’s Health and chief of the division of Reproductive Endocrinology and Infertility at Columbia University Vagelos College of Physicians and Surgeons. “We hope that this test will help improve women’s health, lower costs, and improve access to treatment.”
The most frequent causes of miscarriage, morphological abnormalities, and developmental delays are by far the chromosomal abnormalities that this test can identify. Pregnant women who are 35 years of age or older, have a family history of genetic diseases, or have experienced one or more miscarriages are advised to undergo prenatal genetic testing. It is also increasingly used to evaluate embryos before implantation during in vitro fertilisation (IVF) to increase the likelihood of pregnancy and lower the risk of miscarriage.
The new test uses samples from a biopsy of the placenta or an IVF embryo to check for the presence of a normal number of chromosomes, just like the prenatal genetic testing that are now available. The time and money involved in the existing tests, however, are increased since samples collected at a doctor’s office must be sent to a specialist lab that either grows cells in a dish or employs pricey technology to examine DNA.
“What’s so exciting is that STORK can be used to rapidly assess chromosomal health across all reproductive tissue types,” Williams says. “For those patients who are trying to get pregnant through IVF, the test gives the ability to conceive sooner. For those who are already pregnant, it gives more time to make important family-planning decisions. For those who have had a miscarriage, it can show why the loss happened so that steps can be taken to prevent future pregnancy losses.”
Williams and his team have developed a technique that drastically shortens the time it takes to receive findings by using nanopore-based sequencing technology to evaluate minuscule DNA fragments 15,000 times faster than currently employed chromosomal testing techniques. The test can be used in doctor’s offices since it makes use of considerably smaller, harmonica-sized equipment that weighs only 450 grammes. 218 blinded samples from miscarriages, pregnancies (through amniotic fluid or chorionic villi—tiny growths in the placenta), and embryo biopsy samples were used to evaluate STORK. The outcomes were contrasted with those attained through routine clinical testing. In 98% of the analysed embryos and all of the pregnancy-related samples, STORK results were in agreement with conventional clinical testing.
In the 10 instances when the two tests disagreed, it was found that STORK was more accurate than normal testing and had properly identified the chromosome numbers. At a qualified independent laboratory, 60 more pregnancy samples were analysed using STORK, and the outcomes were consistent with those of conventional clinical testing. The cost of fertility therapy increases by thousands of dollars when IVF embryos, which are generally biopsyed for chromosomal testing on day five or six, are frozen for weeks before being transplanted to a woman’s uterus. With quick diagnostics, freezing might not be necessary because healthy embryos could be transferred right away.
“The affordability of this test also means that individuals who have suffered a miscarriage do not have to wait until a second or third loss before insurance will cover expensive lab tests, leaving many women in the dark and often blaming themselves,” Williams says. “Our study also shows that our rapid test was better than the gold standard for testing miscarriage samples, giving women who have suffered a pregnancy loss a sense of closure and the ability to take steps to prevent another loss.”
The study is titled, “Rapid Nanopore Sequencing-Based Screen for Aneuploidy in Reproductive Care.”