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Updated: Aug 12, 2026
FISH for Pre-implantation Genetic Diagnosis
Published on: February 23, 2011
Clinical experience from Thailand: noninvasive prenatal testing as screening tests for trisomies 21, 18 and 13 in
S Manotaya1,2, H Xu3,4, B Uerpairojkit1,2
1Department of Obstetrics and Gynecology, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand.
Purpose:
The purpose of this article is to report the clinical experience and performance of massively parallel sequencing-based noninvasive prenatal testing (NIPT) as a screening method in detecting trisomy 21, 18, and 13 (T21/T18/T13) in a mixed-risk population in Thailand.
Methods:
In a 30-month period, 121 medical centers in Thailand offered NIPT as clinical screening tests for fetal T21, T18, and T13 in the mixed-risk population. All NIPT-positive cases were recommended to undergo invasive prenatal diagnosis.
Results:
A total of 4736 participants received the NIPT test, including 2840 high-risk pregnancies, either with advanced maternal age or positive serum biochemical tests, and 1889 low-risk pregnancies without conventional indications; 99.9% (4732/4736) of the participants with a median maternal age of 35 years old received reports, and 1.3% (63/4732) were classified as test positive, including 36 T21, 19 T18, and 8 T13; 82.5% (52/63) took prenatal diagnosis, and 11.5% (6/52) false-positive cases were observed. The positive predictive values for the detection of T21, T18, and T13 were 94.4%, 79.0%, and 87.5%, respectively.
Conclusion:
With stringent protocol, our prospective large-scale multicenter nationwide study demonstrated that NIPT showed excellent performance as screening tests for the detection of fetal T21, T18, and T13 in mixed-risk pregnancies in Thailand.
