title: Use of the Combined First-Trimester Screen in High- and Low-Risk Patient Populations After Introduction of Noninvasive Prenatal Testing.
abstract: OBJECTIVE
  To report changes in the use of the combined first-trimester screen (FTS) in patients classified as high and low risk for fetal aneuploidy, including after introduction of noninvasive prenatal testing (NIPT).
  
  
  METHODS
  A prospectively collected database was reviewed to investigate changes in FTS use before and after American College of Obstetricians and Gynecologists (ACOG) Practice Bulletin No. 77 (Obstet Gynecol 2007; 109:217-227), which recommended that all patients be offered aneuploidy screening, and after NIPT introduction. High-risk patients were classified as 35 years or older at the estimated time of delivery or those with an abnormal prior screen, abnormal ultrasound findings, or family history of aneuploidy. Data were normalized per 100 morphologic ultrasound examinations to account for changes in patient number over time. Statistical significance was defined as P < .05.
  
  
  RESULTS
  A total of 10,125 FTSs were recorded during the 88-month study period, including 2962 in high-risk patients and 7163 in low-risk patients. The total number of FTSs performed per 100 morphologic ultrasound examinations significantly increased after ACOG Practice Bulletin No. 77 and significantly decreased after NIPT introduction. In high-risk patients, the total number of FTSs performed per 100 morphologic ultrasound examinations significantly increased after ACOG Practice Bulletin No. 77 but significantly decreased after NIPT introduction. In contrast, in low-risk patients, the total number of FTSs performed per 100 morphologic ultrasound examinations significantly increased after ACOG Practice Bulletin No.77 but was not statistically different after NIPT introduction.
  
  
  CONCLUSIONS
  American College of Obstetricians and Gynecologists Practice Bulletin No. 77 significantly increased patient use of FTS. The introduction of NIPT significantly decreased FTS use in the high-risk population but not in the low-risk population.
authors.affiliation: Division of Maternal-Fetal Medicine, Eastern Virginia Medical School, Norfolk, Virginia USA (S.L., S.L.W., L.R., M.M., A.Z.A.); and Department of Obstetrics and Gynecology, Ziv Medical Center, Bar-Ilan Medical School, Zefat, Israel (D.P.).
authors.forename: Sebastian
authors.initials: S
authors.lastname: Larion
authors.affiliation: Division of Maternal-Fetal Medicine, Eastern Virginia Medical School, Norfolk, Virginia USA (S.L., S.L.W., L.R., M.M., A.Z.A.); and Department of Obstetrics and Gynecology, Ziv Medical Center, Bar-Ilan Medical School, Zefat, Israel (D.P.). warsofsl@evms.edu.
authors.forename: Steven L
authors.initials: SL
authors.lastname: Warsof
authors.affiliation: Division of Maternal-Fetal Medicine, Eastern Virginia Medical School, Norfolk, Virginia USA (S.L., S.L.W., L.R., M.M., A.Z.A.); and Department of Obstetrics and Gynecology, Ziv Medical Center, Bar-Ilan Medical School, Zefat, Israel (D.P.).
authors.forename: Letty
authors.initials: L
authors.lastname: Romary
authors.affiliation: Division of Maternal-Fetal Medicine, Eastern Virginia Medical School, Norfolk, Virginia USA (S.L., S.L.W., L.R., M.M., A.Z.A.); and Department of Obstetrics and Gynecology, Ziv Medical Center, Bar-Ilan Medical School, Zefat, Israel (D.P.).
authors.forename: Margaret
authors.initials: M
authors.lastname: Mlynarczyk
authors.affiliation: Division of Maternal-Fetal Medicine, Eastern Virginia Medical School, Norfolk, Virginia USA (S.L., S.L.W., L.R., M.M., A.Z.A.); and Department of Obstetrics and Gynecology, Ziv Medical Center, Bar-Ilan Medical School, Zefat, Israel (D.P.).
authors.forename: David
authors.initials: D
authors.lastname: Peleg
authors.affiliation: Division of Maternal-Fetal Medicine, Eastern Virginia Medical School, Norfolk, Virginia USA (S.L., S.L.W., L.R., M.M., A.Z.A.); and Department of Obstetrics and Gynecology, Ziv Medical Center, Bar-Ilan Medical School, Zefat, Israel (D.P.).
authors.forename: Alfred Z
authors.initials: AZ
authors.lastname: Abuhamad
mesh_terms: D004314:Down Syndrome / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods / Q000706:statistics & numerical data*; D062145:Maternal Serum Screening Tests / Q000706:statistics & numerical data*; D048208:Nuchal Translucency Measurement / Q000706:statistics & numerical data*; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011296:Prenatal Diagnosis / Q000379:methods / Q000706:statistics & numerical data*; D015995:Prevalence; D015203:Reproducibility of Results; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D014481:United States / Q000453:epidemiology
keywords: combined first-trimester screen; fetal aneuploidy; first-trimester screen; noninvasive prenatal testing; obstetric ultrasound; prenatal screening