With the start of 2016, obstetricians, like everyone else, are making their New Year’s resolutions. Here are their resolutions for counseling their patients about prenatal genetic testing.
I resolve that my patient’s will make an informed choice about whether to accept prenatal genetic testing for conditions like Down syndrome.
I resolve this because this is what my professional organization, the American Congress of Obstetricians & Gynecologist (ACOG), emphasizes: that decisions about prenatal genetic testing should not be routine, but the result of an informed choice. Therefore, I will not have their blood sample tested for Down syndrome or another genetic condition without their informed consent, nor will I offer prenatal testing as something that is the responsible choice or what is part of routine prenatal care.
I resolve not to present cell free DNA test results as “99% accurate.”
In counseling my patients, when I receive test results from companies like Sequenom, Illumina, Harmony, Natera, Progenity, or Integrated Genetics, I will not mistake their claimed sensitivity or specificity for positive predictive value (PPV). Instead, I will present the results as screen results, results which may be a false positive or a false negative, and note that only invasive diagnostic testing can confirm a screen result. If there is confusion about the test results or if my patient has more questions, I will follow up with the testing laboratory.
I will provide my patients the recommended information to accompany a screen result indicative of Down syndrome.
Prenatal testing is about providing information to my patients–that does not stop and start with simply the test result. The American Congress of Medical Genetics & Genomics (ACMG) identified three resources for patients receiving a positive screen result: Lettercase’s Understanding a Down Syndrome Diagnosis, www.brightertomorrows.org, and the American Academy of Pediatrics (AAP) healthcare guidelines for individuals with Down syndrome. Then, the National Society of Genetic Counselors (NSGC) created an easy, downloadable fact sheet of approved information and additional resources about Down syndrome, with the ACMG’s three resources included. And, in September 2015, ACOG incorporated by reference the NSGC fact sheet in ACOG’s statement on cell free DNA screening. This fact sheet is easily accessible on the internet and I can just print it off with each screen result from MaterniT21, Harmony, verifi, Panorama, or the other cell free DNA screen tests. I resolve to provide this recommended information to my patients receiving a screen result indicative for Down syndrome.
By keeping these resolutions, I’ll be abiding by my professional guidelines, and providing the information recommended for patients undergoing cell free DNA screening. This will result in better prenatal care in 2016.
Very good resolutions!
I suppose these “resolutions” are in effect seeing that this was the case when I received my phone call today… Genetic counselor calls to inform me that my Maternit21 results came back positive and my baby has an 80% chance of Downs. Which to me is basically saying my baby has Downs. Needless to say the “genetic councilor” advised I come in to discuss my results. And to schedule amnio. I told her I needed time to process seeing I lost my first child a daughter to hypoplastic left heart syndrome due to Turners syndome. She went full term and lived an hour. Now I have been blindsided by the likelihood my next baby has DS. I am 36 and honestly wish I never was offered this test. I don’t know if I can survive what has been set upon my shoulders again. Is thereally something wrong with me for this to happen twice??
I can’t say there’s anything wrong with you for having one child with Turners syndrome and now a cfDNA result for Down syndrome. Based on your age, around 80% is the positive predictive value, meaning there is a 20% chance of a false positive. While more likely than not, a 1-in-5 chance of the test being a false positive is still not insignificant. If you weren’t provided it with your test, I hope you’ll find the prenatal resources about Down syndrome at this tab helpful.
I am just concerned there is something in my genes or dna attributing to my higher risk and predisposition to passing on genetic and/or chromosomal abnormalities besides my AMA. I am scheduled for the amnio tomorrow for my definitive results on the T21 result. My brain could not compute the numbers and percentages of what having an 80% positive result meant considering my age, previous diagnosis and the accuracy of the test factored together. So thank you for that and for the links.
Interesting read. Just an FYI, ACMG is American College of Medical Genetics and Genomics (not congress)
Thanks. I sometimes get them confused with ACOG (which even confuses itself with college/congress).