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Photo: courtesy Travel Alberta

Early Risk Assessment Program: Performance Update 2008. Photo: courtesy Travel Alberta. Screening for Fetal Aneuploidy 11-13+6 weeks. Objectives:. The provision of information for individuals. 32 nd RCOG Study Group.

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Photo: courtesy Travel Alberta

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  1. Early Risk Assessment Program: Performance Update 2008 Photo: courtesy Travel Alberta

  2. Screening for Fetal Aneuploidy 11-13+6 weeks Objectives: • The provision of information for individuals 32nd RCOG Study Group • Women have the right to access information about the health of their fetus SOGC Statement on Access to Genetic Screening January 2007

  3. Recommendations J Obstet Gynaecol Can 2007;29 (2):146-161 1. All pregnant women in Canada, regardless of age, should be offered through an informed consent process, a prenatal screening test for the most common clinically significant fetal aneuploidies in addition to a second trimester ultrasound for dating, growth and anomalies. (I-A)

  4. AMNIOCENTESIS 2. Maternal age screening is a poor minimum standard for prenatal screening for aneuploidy and should be removed as an indication for invasive testing. Amniocentesis/chorionic villi sampling (CVS) should not be provided without multiple marker screening results except for women over the age of 40. Patients should be counseled accordingly. (I-A)

  5. 3. In 2007, as a minimum standard, any prenatal screen offered to Canadian women should have a 75% detection rate with no more than a 5% false positive rate (3% by 2008) for Down syndrome. The performance should be substantiated by annual audit. (III-B). Wald et al. 2003; Nicolaides et al. 2005

  6. 11. By 2008, screening programs should aim to provide a screen that, as a minimum, offers women who present in the first trimester a detection rate of 75% for Down syndrome, with no more than a 3% false positive rate. (III-B)

  7. 4. First trimester nuchal translucency should be interpreted for risk assessment only when performed by sonographers/sonologists trained and accredited to provide this service and with ongoing quality assurance.(II-2A) It should not be offered as a screen without biochemical markers except in the context of multiple gestation pregnancies (I-A).

  8. Principles of Screening Characteristics of Screening Test Sensitivity (Detection rate): Abn screen, abn result False Positive Rate*: Abn screen, normal result False Negative Rate: Normal screen, abn result Specificity: Normal screen, normal result = 100-FPR Likelihood Ratio: Proportn Abn / Proportn Normal * Also called initial positive rate, is used interchangeably with amniocentesis rate

  9. Background risk Adjusted risk = X Background- (a priori) risk Nuchal Translucency X X LR of screening test Biochemistry X Adjusted risk = a priori risk x LR1 x LR2 x LR3… New Marker Screening for trisomy 21

  10. Prenatal Screening in Alberta • Maternal age alone • MSS 1990’s • Not a funded program, no audit or follow-up In Calgary • Nuchal translucency screening* 2002 • No MSS after NT, unless with genetic counseling • 18-20 week scan Nuchal Translucency Screening* (NTS) Maternal Serum Screen (MSS) AFP,uE3,hCG Detailed Anatomy Genetic Sonogram* Pregnancy Outcome AMNIO CVS 11-14 15-17 18-20 *Southern Alberta Center for Maternal Fetal Medicine (MFM Centre)

  11. Prenatal Screening in Calgary Nuchal Translucency Screening Clinic* (2002-March 2006) • Pre- and post-NT counselling • 18 “NT certified” technologists • # of patients given NT-adjusted risk n= 9,971 • DR 75%, FPR 9 % at 1/300 (mid-TM risk) • 32% ≥ 35 years of age UNACCEPTABLE FPR: NEED BIOCHEMISTRY *Southern Alberta Center for Maternal Fetal Medicine (MFM Centre)

  12. Screening for Trisomy 21 Fetal NT + maternal free ß-hCG & PAPP-A (FTS) • The best marker is NT • Inclusion of ß-hCG and PAPP-A improves DR by 15-20% • Five prospective studies of FTS (n=76,977), DR of Tr21 362/409 (89% for 5% FPR)

  13. The Early Risk Assessment (ERA) Program: First Trimester Screening and Early Detection of Pregnancy Complications GOAL “To promote the health and well-being of pregnant women through a collaborative and multidisciplinary prenatal risk assessment program that would enable early, more accurate identification and management of pregnancies at increased risk for adverse perinatal health outcomes”.

  14. Early Risk Assessment Program : Prenatal Screening for Chromosome Disorders First Trimester Combined Screening • Purpose: • To introduce FTS (OSCAR model) • To develop patient and physician educational materials • To evaluate program performance and patient satisfaction • Maternal age • NT • Free-bHCG • PAPP-A

  15. Early Risk Assessment Program: Earlydetection ofPregnancies at risk of Adverse Outcome 1. To examine the predictive value certain biochemical/US markers (11 -20 w) in detection of women at increased risk of poor pregnancy outcome (pre-eclampsia, IUGR, preterm labor), 2. To identify risk factors and interventions that may improve pregnancy outcome in this group MSS Genetic sonogram FTS 10 12 14 16 18

  16. Why “Point of Care?” One Stop Clinics • One stop clinics have developed in several clinical areas • breast cancer screening, menopausal clinics, oncology assessment, cardiovascular risk clinics, one-stop surgical clinics • Benefits: • integration of clinical and diagnostic services • better use of clinical time, improved diagnostic efficiency

  17. OSCAR: “One-Stop Clinic Assessment of Risk” • Patient advantages: • Maximizes patient satisfaction • Reduced number of patient visits • Decreased patient travel costs, (missing work, babysitting, parking), anxiety, and stress especially that associated with waiting for results • Allows for timely, qualified interpretation of results

  18. Evidence and Innovations leading to OSCAR • Ultrasound markers of chromosomal anomalies - fetal nuchal translucency thickness at 11-14 weeks. • Maternal serum Biochemical markers of chromosomal anomalies - free b-hCG & PAPP-A at 10-14 weeks. • Development of new rapid assay technology for biochemical marker measurement leading to Point of Care testing.

  19. OSCAR in Calgary* One Stop Clinic for Assessment of RiskSouthern Alberta Centre for MFM (NT clinic + Astraia) + (DELFIAXpress + Lifecycle) = OSCAR Woman arrives Woman departs Post-test counselling Pre-test counselling* Free b HCG PAPP-A NT SCAN Blood sample Risk Assessment Ultrasound Examination (11-13+6 weeks scan) U/S data * Mean T/O time 92 minutes *1-1 Counselling, video, pamphlets www.earlyriskassessment.com Invasive testing usually not same day

  20. OSCAR in Calgary FTS Uptake March 2006-2007

  21. Non-OSCAR in Calgary(2-Step Model) Woman arrives “-ve screen” Report mailed “+ve screen” Nurse/ counsellor calls, appointment arranged Step 1 • Demographics reviewed • Counselling as needed • Consent signed Risk Assessment Same day report NT Ultrasound Examination 2 MFM sites Woman departs Blood sample Free b HCG,PAPP-A OSCAR facility U/S data *Own MD, website, pamphlets Step 2

  22. First Trimester Serum Screening Detection 1/250 Risk cut-off Biochemistry Works Better Earlier Spencer et. Al Ann. Clin. Biochem. 2003; 40: 219-231

  23. “Non”-OSCAR One Stop Clinic for Assessment of RiskSouthern Alberta Centre for MFM Woman departs Woman referred for FTS Directed to educational materials* Post-test counselling Free b HCG PAPP-A NT Scan Blood sample at any CLS facility starting at 9 weeks gestation Risk Assessment NT Ultrasound At Beddington or Southport EFW MFM Clinics Free b HCG PAPP-A www.earlyriskassessment.com

  24. Mean Maternal Age (* 18% in the CHR ≥ 35 years)

  25. FTS Performance:Screening for Trisomy 21

  26. FTS Performance March 13 2007- March 13 2008 Total number screened 6984 Initial positive rate (or False Positive rate):T21

  27. FTS Performance March 13 2007- March 13 2008 • Screening for Trisomy 21 • DR Trisomy 21 93% (29/32), FPR 6.5% (1/300) • 2 “false negative” cases: • 1 negative screen for T21, +ve T13,18 (had invasive) • Other case: no blood obtained, NTS alone. • Characteristics of the T21 cases • 27/ 31 Trisomy 21 (87%) detected prenatally • CVS 17/27 (63%), amnio10/26 (38.4%) • 3 LB T21 in screen +ve group (declined invasive) • 1 had no invasive (FN result) • Risk assessment on NT alone due to unsuccessful phlebotomy

  28. FTS Performance March 13 2007- March 13 2008 • Invasive testing in FTS screened patients • Overall invasive rate: 292/6983 = 4.1 % • Invasive rate among screen +ve patients: 229/439 = 52% • Average risk of screen positive patients who had invasive testing 1:90 • Average age 34 years, 53% over 35,13% over 39 • Average risk of screen positive patients who did not have invasive testing 1:151 • Average age 34 years, 53% over 35, 20% over 39

  29. FTS in Calgary 2006-7 Characteristics of the true +ve (T21) screens (n=20) Mean GA 60 mm Mean T21 risk: 1:22 Mean NT: 3.6 (range 1-8.2 mm) Average age 36.3 years (range 22-45, 68% over 35 years) Average fβ-HCG 2.5 MOM (range 0.7-4.24) Average PAPP-A 0.5 MOM (range 0.12-0.95) OAPR: 1:16

  30. FTS in Calgary 2007-8 Characteristics of the true +ve (T21) screens (n=29) Mean GA 66 mm Mean T21 risk: 1:43 Mean NT: 3.9 Average age 36.7 years (range 22-45) Average fβ-HCG 2.5 MOM (range 0.5-6.0) Average PAPP-A 0.6 MOM (range 0.1-2.1) OAPR: 1:15

  31. FTS in Calgary 2006-8 Characteristics of the Trisomy 21 cases (n=23) • Average age 36.5 • Average risk in true positives: 42 • 26/49 (53%) had 1:2, • 37/49 (77%) 1:10 or higher. • 44/49 (89%)1:150 or higher

  32. FTS Program in Calgary • Key Points • One-stop multidisciplinary approach associated with high patient satisfaction • Operationally efficient (few call backs, demographic and ultrasound information available, collaborative atmosphere between disciplines (MFM, genetics, ultrasound, lab, nursing). • Established infrastructure for efficient high quality ultrasound as well as audit and research (linked to Alberta Perinatal Health database) • Ability to introduce new markers/ protocols • Performance excellent and within expected range

  33. Province of Alberta: Proposed Program • For women presenting for prenatal care before 13 weeks and 6 days of pregnancy, there would be two options: • Where Nuchal Translucency available: • First trimester Combined Screening (FTS, GOLD STANDARD) • Where Nuchal Translucency not available: • Early Contingent Screening • Combines maternal age with blood test (biochemical markers: PAPP-A and free beta HCG ) • If risk assessment is above the predetermined risk cut-off, a nuchal translucency ultrasound would be recommended (estimate10- 20% of population). • For women presenting for prenatal care after 14 weeks and before 19 weeks and 6 days: • Second trimester Quad Maternal Serum Screening

  34. Community-based screening for Down’s Syndrome in the first trimester using ultrasound and maternal serum biochemistry • 2 year pilot study in Western Australia, a geographically isolated state with an annual birth rate of 25,000. • Outcomes linked to State wide birth and anomaly information systems. • FTS is largely community based with women accessing a variety of independent ultrasound practices and local collection centres served by one central laboratory with distances in some instances over 1000 Km away. Narelle Hadlow et al, BJOG 2005:112; 1561-1564

  35. Community-based screening for Down’s Syndrome in the first trimester using ultrasound and maternal serum biochemistry • In the study period NT was only concentrated in the Perth Metro area. • Women had blood collected at their local collection centre in their rural community (over 100 sites). Separated, frozen and sent by air or land transport in frozen state. • Women travelled to Perth for NT, biochemistry result available on day of scan in 96% of cases, and after the NT in 4% of cases. • Study screened over 10,000 women and detection rate was 90.6% with a false positive rate of 3.6% (Mean age 30.7 ) • All sonographers/obstetricians FMF approved and either trained in London or via the FMF delegated RANZCOG program Narelle Hadlow et al, BJOG 2005:112; 1561-1564

  36. Delivery of Screening • Multidisciplinary !! • Numerous stakeholders: • Pregnant women, MFM, obstetrics, family medicine, midwives, radiology, sonography, lab services, genetics, pathology……… • Direction of flow Ultrasound Biochemistry

  37. OSCAR in Calgary Number of abnormal cytogenetic results n= 39 (Ascertainment: electronic linkage with Alberta perinatal health database and cytogenetic lab; outcome not complete) +ve screen -ve screen Total detected prenatally 37/39 (95%)

  38. Uterine Arteries NB, TC, DV, FMF Angle Placental hormones Anatomic Survey 11-13 weeks 6 days scan Multiples Nuchal Screening The First Trimester Scan (11-13 weeks 6 days)

  39. Biochemical Screening: Centralized vs POC Centralized laboratory services • Minimizes costs • High standards • Can serve locally, regionally, nationally • “Point of Care” • Not as common in non-private HC systems • Costs offset by operational efficiency, consolidation of services, fewer patient visits, better care

  40. Prospective 1st Trimester Screeningsingleton pregnancies over a 5 year period NT alone would have picked up 70% of cases at a 5% FPR, Biochemistry alone would have picked up 70% at a 5% FPR but combined a further 22% are identified

  41. RESULTS Satisfaction with OSCAR program These results were independent of maternal age, parity, education and screen result, except women with lower education levels were significantly more likely to be satisfied with pre-test counseling than women with higher education levels (p=0.0071)

  42. Satisfaction with Overall Serviceby Service Delivery Model • Although satisfaction with overall service was high for both the one-stop and two-stop service delivery models, women who had the one-stop service were more likely to be satisfied than women who had the two-stop service (p<0.0001). Missing Responses: 135

  43. OSCAR Satisfaction Study • Uptake of invasive testing in women attending the OSCAR clinic: • Positive screen (T21): 49.1% • Negative screen: 2.7% • Invasive uptake related to level of risk 1/100 1/100-1/1000 >1/1000 *DR of T21 87% at 5% FPR

  44. Early Prenatal Risk Assessment: More Than an Aneuploidy Screen 11-14 WEEK SCAN NT, NB Fetal anatomy UA Doppler Placental morphology 1st TM Volume (3D) Maternal Serum PAPP-A Free beta hCG Store sample DETAILED ANATOMY Fetal echo Uterine artery Doppler Placental morphology Timing of scan Maternal Serum AFP,uE3,hCG DIA? Contingent screening Store sample TV cervix clinic U/A Doppler Cervical length (c/w 18-20 week) 11-14 15-17 18-20 22-24 PHASE 1: FTS PHASE 2: Pregnancy complications

  45. OBJECTIVES Purpose: 1.) To evaluate women’s satisfaction with first trimester combined screening (FTS), 2.) To compare delivery models (one-stop (OSCAR*) versus 2-stop screening). *March 13, 2006- March 13, 2007 # Women screened n= 5013 # Completed surveys n= 3763 (75%) Eligible OSCAR patientsn=2670/3763 (71%)

  46. CONCLUSIONS • The Calgary FTS OSCAR model meets women’s expectations, is associated with a high degree of satisfaction and was preferred over the 2-stop model • Receiving results early in pregnancy and same day is important • A high proportion of women were reassured by their results regardless of whether they were screen negative or positive. • Uptake of invasive prenatal diagnosis among screen positive patients correlated with level of risk

  47. CONCLUSIONS cont’d • These results may imply that • Women favor individualized risk assessment versus being categorized as screen negative or positive • Immediate access to 1-1 post-test counseling with a health professional, as in the OSCAR model, has important impact on perception of test results • Further research to evaluate this is under consideration • The 2 stop model has been revised …

  48. FTS Performance:Screening for Trisomy 13/18

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