title: Noninvasive prenatal testing for whole fetal chromosomal aneuploidies: a multicenter prospective cohort trial in Taiwan.
abstract: OBJECTIVE
  To evaluate the performance of noninvasive prenatal testing for all fetal chromosomal aneuploidies in an extremely high-risk group undergoing first trimester combined Down syndrome screening.
  
  
  METHODS
  A multicenter cohort prospective study in Taiwan was performed between June and December 2012. Maternal plasma was collected and shotgun massive parallel sequencing was performed on each fetal chromosome. 201 Taiwanese pregnant women at >12 weeks' gestation from 11 medical centers were enrolled in this trial. The extremely high-risk group was defined as a Down syndrome risk cutoff >1:30 or nuchal translucency >3.0 mm (n = 100), while the low-risk group was defined as a Down syndrome cutoff <1:1,500 (n = 101). Amniocentesis confirmation was performed and birth outcome was also recorded.
  
  
  RESULTS
  There were 11 cases of trisomy 21, 8 cases of trisomy 18, 3 cases of trisomy 13, 1 case of trisomy 16, 3 cases of 45,X, and 1 case of 47,XYY detected prenatally in 100 extremely high-risk gravidas [n = 27/100 (27%)]. The overall autosomal or sex chromosome aneuploidy detection rate was 96% (27/28) because of an insufficient amount maternal plasma for one fetus with Turner syndrome. In the low-risk group, no chromosomal abnormalities were detected (specificity = 100%). There were no false-positive cases in this study.
  
  
  CONCLUSIONS
  This first trial in Taiwan shows that noninvasive prenatal testing for whole chromosome aneuploidies can be efficiently applied in extremely high- and low-risk populations.
authors.affiliation: Department of Obstetrics and Gynaecology, Chang Gung Memorial Hospital at Linkou, College of Medicine, Chang Gung University, Taoyuan, PR China.
authors.forename: S W Steven
authors.initials: SW
authors.lastname: Shaw
authors.forename: Ching-Hua
authors.initials: CH
authors.lastname: Hsiao
authors.forename: Chih-Yao
authors.initials: CY
authors.lastname: Chen
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Ren
authors.forename: Feng
authors.initials: F
authors.lastname: Tian
authors.forename: Chris
authors.initials: C
authors.lastname: Tsai
authors.forename: Ming
authors.initials: M
authors.lastname: Chen
authors.forename: Po-Jen
authors.initials: PJ
authors.lastname: Cheng
mesh_terms: D000782:Aneuploidy; D025063:Chromosome Disorders / Q000175:diagnosis*; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007621:Karyotyping; D062145:Maternal Serum Screening Tests; D011247:Pregnancy; D012729:Sex Chromosome Aberrations; D013624:Taiwan