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Updated: May 27, 2026

Semiconductor Sequencing for Preimplantation Genetic Testing for Aneuploidy
Published on: August 25, 2019
Stepwise sequential aneuploidy screening in clinical practice
Joseph R Wax1, Angelina Cartin, Dwight Smith
1Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Maine Medical Center, Portland, ME, USA.
Purpose:
To evaluate stepwise sequential screening (SSS) efficiency in clinical practice.
Methods:
All singletons undergoing SSS in a single practice by NTQR (Nuchal Translucency Quality Review Program)-credentialed providers in a 2-year period were included. Prenatal diagnosis was offered to all screen-positive women and those with a nuchal translucency ≥3.5 mm or cystic hygroma at the 11- to 14-week scan. Data were extracted from prospectively ascertained serum screening and genetics databases.
Results:
A total of 2,726 patients were screened, with SSS detecting all eight cases of trisomy 21 and all seven cases of other aneuploidies at a 4.3% screen-positive rate.
Conclusions:
Stepwise sequential screening offers excellent aneuploidy screening efficiency when introduced into clinical practice.
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