Sequential pathways of testing after first-trimester screening for trisomy 21 Article

cited authors

  • Platt, LD; Greene, N; Johnson, A; Zachary, J; Thom, E; Krantz, D; Simpson, JL; Silver, RK; Snijders, RJM; Goetzl, L; Pergament, E; Filkins, K; Mahoney, MJ; Hogge, WA; Wilson, RD; Mohide, P; Hershey, D; MacGregor, S; Bahado-Singh, R; Jackson, LG; Wapner, R

fiu authors

abstract

  • OBJECTIVE: To evaluate the performance and use of second-trimester multiple-marker maternal serum screening for trisomy 21 by women who had previously undergone first-trimester combined screening (nuchal translucency, pregnancy-associated plasma protein A, and free β-hCG), with disclosure of risk estimates. METHODS: In a multicenter, first-trimester screening study sponsored by the National Institute of Child Health and Human Development, multiple-marker maternal serum screening with alpha-fetoprotein, unconjugated estriol, and total hCG was performed in 4,145 (7 with trisomy 21) of 7,392 (9 with trisomy 21) women who were first-trimester screen-negative and 180 (7 with trisomy 21) of 813 (52 with trisomy 21) who were first-trimester screen-positive. Second-trimester risks were calculated using multiples of the median and a standardized risk algorithm with a cutoff risk of 1:270. RESULTS: Among the first-trimester screen-negative cohort, 6 of 7 (86%) trisomy 21 cases were detected by second-trimester multiple-marker maternal serum screening with a false-positive rate of 8.9%. Among the first-trimester screen-positive cohort, all 7 trisomy 21 cases were also detected in the second trimester, albeit with a 38.7% false-positive rate. CONCLUSION: Our data demonstrate that a sequential screening program that provides patients with first-trimester results and offers the option for early invasive testing or additional serum screening in the second trimester can detect 98% of trisomy 21-affected pregnancies. However, such an approach will result in 17% of patients being considered at risk and, hence, potentially having an invasive test. © 2004 by The American College of Obstetricians and Gynecologists.

publication date

  • October 1, 2004

Digital Object Identifier (DOI)

start page

  • 661

end page

  • 666

volume

  • 104

issue

  • 4