May 1, 2020
Letter to Physicians RE: Self-pay NIPT in Nova Scotia
FROM:
Jo-Ann Brock, MD, PhD, FRCSC,
Division Head, Clinical Genomics Laboratory, IWK Health Centre
Heather Scott, MD, FRCSC, Maternal-Fetal Medicine Specialist
Obstetrical Co-Director, Reproductive Care Program of Nova Scotia
Sandhya Parkash, MD, FRCPC, Medical Geneticist
Maritime Medical Genetics Service, Head of Prenatal Genetics
TO: All Health Care Professionals delivering early prenatal care.
There has recently been an increase in number of requests among pregnant patients and their care providers for information related to non-invasive prenatal testing (NIPT, also known as NIPS). NIPT is a screening test primarily for common aneuploidy, including Trisomies 13, 18, 21 and sex chromosome aneuploidy (SCA).
NIPT is currently used in Nova Scotia as a second tier screen for patients with a high risk screening result for Trisomy 21 in lieu of invasive testing. This testing is offered to patients when they are seen by Maternal Fetal Medicine or Medical Genetics after being identified as high risk through standard maternal serum screening. NIPT is not used in Nova Scotia as part of the screening for Trisomies 13, 18 or SCAs.
According to the Joint Canadian College of Medical Geneticists (CCMG)/Society Obstetricians and Gynaecologists of Canada (SOGC) guidelines, “patients should be offered… maternal plasma cell-free DNA screening [NIPT] where available, with the understanding that it may not be provincially funded” [JOGC 39(9): 805-817]. In addition, a recent publication in JOGC suggests that failure to inform a patient about NIPS could result in successful “wrongful birth” claims [https://doi.org/10.1016/j.jogc.2020.03.020].
If a patient wishes to have NIPT in lieu of standard screening, or after receiving a low risk screening result after standard screening, they have the option to pay for this test through an independent referral laboratory. Accessing self-pay NIPT still requires involvement of a health care professional (HCP) for counselling and consent prior to testing, and to receive and deliver results to the patient. In order to access testing, the referral laboratory must be contacted by the patient or HCP to arrange a collection kit to be sent to the patient. This kit will include the appropriate blood collection tubes, and all the necessary paperwork and packaging to request the test and ship the sample to the lab.
NIPT can be done as early as 10 weeks in gestation, and patients who choose to pay for NIPT at any point in their pregnancy should then not undertake any further maternal serum testing. Patients should be aware that the positive predictive value can be as low as 50% in a low risk population.
Some laboratories also offer NIPT for microdeletions and duplications, such as DiGeorge syndrome, Williams Syndrome, Cri-du-chat etc. Performance of NIPT in screening for microdeletion and microduplication syndromes is not well documented due to the rarity of these conditions, and NIPT is not recommended for microdeletion and microduplication syndromes according to the Joint CCMG/ SOGC guidelines [JOGC 39(9): 805-817].
Further information to assist patients and care providers understand the issues around decision-making and accessing self-pay NIPT is available on the IWK Clinical Genomics Laboratory website: http://www.iwk.nshealth.ca/clinical-genomics.