Value of noninvasive prenatal testing in the detection of rare fetal autosomal abnormalities.

Zhang M, Tang J, Li J, et al. Eur J Obstet Gynecol Reprod Biol. 2023;284:5-11. doi:10.1016/j.ejogrb.2023.03.002. Open Access: Learn more

Tags: Clinical Experience / Clinical Utility, 2023, China, RAAs, CNVs

  • “Results: NIPT detected 292 cases (0.36%) with rare autosomal abnormalities among the 81,518 cases sampled. Of these, 140 (0.17%) showed rare autosomal trisomies (RATs), and 102 of these patients agreed to undergo invasive testing. Five cases were true positives, with a positive predictive value (PPV) of 4.90%. Copy number variants (CNV) were detected in 152 samples of the total cases (0.19%), and 95 of the patients involved agreed to the use of CMA. Twenty-nine of these cases were confirmed to be true positive, with a PPV of 30.53%. Detailed follow-up information was obtained in 81 cases from 97 patients with false-positive results for RATs. Thirty-seven of these cases (45.68%) had adverse perinatal outcomes, with a higher incidence of small for gestational age (SGA), intrauterine growth retardation (IUGR), and preterm birth (PTB).”
  • “Conclusions: NIPT is not recommended for screening for RATs. However, considering that positive results are associated with an increased risk of IUGR and PTB, additional fetal ultrasound examination should be performed to monitor fetal growth. In addition, NIPT has a reference value in screening for CNVs, especially pathogenic CNVs, but a comprehensive analysis of prenatal diagnosis combined with ultrasound and family history is still needed.”