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Updated: Sep 1, 2025

FISH for Pre-implantation Genetic Diagnosis
Published on: February 23, 2011
Positive predictive value of noninvasive prenatal testing for sex chromosome abnormalities
Nan Guo1, Meiying Cai1, Min Lin1
1Medical Genetic Diagnosis and Therapy Center, Fujian Maternity and Child Health Hospital, College of Clinical Medicine for Obstetrics & Gynecology and Pediatrics, Fujian Medical University, Fujian Key Laboratory for Prenatal Diagnosis and Birth Defect, Fuzhou, China.
Background:
Early and intermediate serological screening cannot detect sex chromosome abnormalities. Currently, noninvasive prenatal testing (NIPT) is the only procedure available for screening such disorders; however, its use is controversial.
Methods And Results:
A total of 47,855 pregnant women underwent NIPT at our referral center from January 2014 to December 2020. Of the 314 patients with a positive NIPT indicating sex chromosome abnormalities, 260 were screened via karyotype analysis and single nucleotide polymorphism (SNP) array after amniotic fluid extraction; 96 cases were confirmed. Karyotype analysis and SNP array were consistent in the diagnosis of 88 out of the 96 fetuses. The positive predictive value (PPV) for sex chromosome abnormalities was found to be 36.9%. The PPV in patients aged 30-34 years was significantly higher than that in patients aged < 30 years. No statistically significant difference was observed on the PPV among patients with or without previous adverse pregnancy outcomes. Moreover, 83 women carrying fetuses were diagnosed with a sex chromosome abnormality terminated their pregnancy.
Conclusions:
Improvements in detection and analytical technologies are needed to increase the accuracy of sex chromosome abnormalities detection. Pregnant women with a positive NIPT for these abnormalities may require invasive diagnostic procedures such as karyotype analysis and SNP array for better genetic counseling.
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