title: Survey of prenatal counselling practices regarding aneuploidy risk modification, invasive diagnostic procedure risks, and procedure eligibility criteria in Canadian centres.
abstract: OBJECTIVE
  To explore prenatal practices related to aneuploidy screening, risk modification, and invasive diagnostic procedures across Canadian centres.
  
  
  METHODS
  We conducted a survey of members of the Canadian Association of Genetic Counsellors, the Canadian College of Medical Genetics, and the Canadian Society of Maternal Fetal Medicine, who provide direct counselling or management of prenatal patients in Canada.
  
  
  RESULTS
  Eighty-two of 157 respondents indicated that their centre's definition of advanced maternal age was ≥ 35 years, with 33/157 respondents reporting an advanced maternal age definition of  ≥ 40 years. The majority of respondents reported that prenatal serum screening for aneuploidy is provincially funded in their province or territory (121/147). The majority of respondents who reported that prenatal screening is not provincially funded (17/147) were from Quebec (14/17). Thirty-nine of 123 respondents reported that their centre defines increased nuchal translucency as  ≥ 3.0 mm, whereas 49/123 reported a definition of ≥ 3.5 mm. Sixty-four of 150 respondents reported that the aneuploidy risk provided by serum screening is modified by a soft marker likelihood ratio, whereas 46/150 respondents reported that both age-related and serum screening risks are modified. Fifty-nine of 124 respondents reported that their centre will modify aneuploidy risk after a normal ultrasound; the most commonly cited negative likelihood ratio was 0.5. The most commonly reported procedure-related risk for chorionic villus sampling was 1/100 (123/147) and for amniocentesis was 1/200 (73/142).
  
  
  CONCLUSIONS
  This study demonstrates inconsistencies in prenatal practices and access to screening programs across Canada. The information gained from this study will inform policy advisors developing prenatal practice guidelines at both the provincial and national levels.
authors: Clinical Genetics Unit, Kingston General Hospital, Kingston ON.
authors: Danna
authors: D
authors: Hull
authors: Gregory
authors: G
authors: Davies
authors: Christine M
authors: CM
authors: Armour
mesh_terms: D000649:Amniocentesis / Q000009:adverse effects; D000782:Aneuploidy; D015415:Biomarkers / Q000097:blood; D002170:Canada; D015193:Chorionic Villi Sampling / Q000009:adverse effects; D005260:Female; D005817:Genetic Counseling; D006801:Humans; D008423:Maternal Age; D011247:Pregnancy; D011295:Prenatal Care / Q000379:methods*; D011296:Prenatal Diagnosis / Q000009:adverse effects* / Q000191:economics / Q000379:methods*; D012051:Reimbursement Mechanisms; D012306:Risk; D011795:Surveys and Questionnaires; D014427:Twins; D016216:Ultrasonography, Prenatal
chemical_list: D015415:Biomarkers