What happens if your cfDNA result is positive
A sequence, not a conclusion.
The recommended sequence is genetic counselling, a detailed ultrasound, and the offer of a diagnostic test to confirm. Only the diagnostic test can tell you whether the condition is actually present.
This does not always happen. In a survey of 207 obstetric clinicians, 19.4% of general practitioners said they would offer termination immediately after a positive cfDNA result without diagnostic confirmation. None of the maternal-fetal medicine specialists said they would.
Uptake of confirmatory testing has also fallen. In one clinic, diagnostic testing after a positive screen dropped from 46.8% to 28.8% in the year after cfDNA became available.
Say this out loud"I want diagnostic confirmation before any decision." You are entitled to it, and the guideline recommends it.
Where this comes from:
145. American College of Obstetricians and Gynecologists' Committee on Practice Bulletins-Obstetrics, Committee on Genetics, Society for Maternal-Fetal Medicine. Screening for fetal chromosomal abnormalities. ACOG Practice Bulletin No. 226. Obstet Gynecol. 2020;136(4):e48-e69.
155. Chan WV, Johnson JA, Wilson RD, Metcalfe A. Obstetrical provider knowledge and attitudes towards cell-free DNA screening: results of a cross-sectional national survey. BMC Pregnancy Childbirth. 2018;18(1):40.
156. Shah FT, French KS, Osann KE, Bocian M, Jones MC, Korty L. Impact of cell-free fetal DNA screening on patients' choice of invasive procedures after a positive California prenatal screen result. J Clin Med. 2014;3(3):849-864.
Covered in the essential classes
Continue
More from Screening and testing
This page is educational. It supports the conversation with your own clinicians. It is not consent to any treatment, and it cannot assess you. If you are worried about a symptom now, see urgent warning signs.