title: Beyond Trisomy 21: Additional Chromosomal Anomalies Detected through Routine Aneuploidy Screening.
abstract: Prenatal screening is often misconstrued by patients as screening for trisomy 21 alone; however, other chromosomal anomalies are often detected. This study aimed to systematically review the literature and use diagnostic meta-analysis to derive pooled detection and false positive rates for aneuploidies other than trisomy 21 with different prenatal screening tests. Non-invasive prenatal testing had the highest detection (DR) and lowest false positive (FPR) rates for trisomy 13 (DR: 90.3%; FPR: 0.2%), trisomy 18 (DR: 98.1%; FPR: 0.2%), and 45,X (DR: 92.2%; FPR: 0.1%); however, most estimates came from high-risk samples. The first trimester combined test also had high DRs for all conditions studied (trisomy 13 DR: 83.1%; FPR: 4.4%; trisomy 18 DR: 91.9%; FPR: 3.5%; 45,X DR: 70.1%; FPR: 5.4%; triploidy DR: 100%; FPR: 6.3%). Second trimester triple screening had the lowest DRs and highest FPRs for all conditions (trisomy 13 DR: 43.9%; FPR: 8.1%; trisomy 18 DR: 70.5%; FPR: 3.3%; 45,X DR: 77.2%; FPR: 9.3%). Prenatal screening tests differ in their ability to accurately detect chromosomal anomalies. Patients should be counseled about the ability of prenatal screening to detect anomalies other than trisomy 21 prior to undergoing screening.
authors.affiliation: Department of Obstetrics and Gynaecology, University of British Columbia, BC Women's Hospital 4500 Oak St., Vancouver, BC V6H 3N1, Canada. ametcalfe@cfri.ca.
authors.forename: Amy
authors.initials: A
authors.lastname: Metcalfe
authors.affiliation: Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada. catriona.hippman@ubc.ca.|Women's Health Research Institute, BC Women's Hospital, 4500 Oak St., Vancouver, BC V6H 3N1, Canada. catriona.hippman@ubc.ca.
authors.forename: Catriona
authors.initials: C
authors.lastname: Hippman
authors.affiliation: Early Risk Assessment Program, Suite 100 3820 Hospital Dr NW, Calgary, AB T2N 4N1, Canada. melanie.pastuck@albertahealthservices.ca.
authors.forename: Melanie
authors.initials: M
authors.lastname: Pastuck
authors.affiliation: Department of Obstetrics and Gynaecology, Foothills Medical Centre-North Tower, University of Calgary, 1403 29th St. NW, Calgary, AB T2N 2T9, Canada. joann.johnson@albertahealthservices.ca.
authors.forename: Jo-Ann
authors.initials: JA
authors.lastname: Johnson
keywords: aneuploidy; maternal serum; non-invasive testing; prenatal; sensitivity; specificity; ultrasound