Background: This study aimed to evaluate the value of non-invasive prenatal testing (NIPT) in the prenatal screening of foetal aneuploidy-associated diseases at different gestational ages.
Methods: Briefly, cell-free foetal DNAs were extracted from plasma first, followed by DNA sequencing and bioinformatics analyses for chromosome aneuploidy (T21, T18, and T13), sex chromosome aneuploidy (SCA), and microdeletion/microduplication. Subsequently, the positive results were subject to karyotype analyses.
Results: The pregnant women included in this study were divided into six groups, and the results, such as chromosome diagnoses, and clinical phenotypes, were collected for data analyses. According to the results of the data analysis, the positivity rates of foetal chromosomal abnormalities in pregnant women under 20, 20-24, 25-29, 30-34, 35-39, and >40 years old were 0%, 0.17%, 0.25%, 0.27%, 0.60%, and 1.66%, respectively. The positive predictive value (PPV) in the 20-24 years group was 41.67%, that in the 25-29 years group was 62.5%, that in the 30-34 years group was 66.67%, that in the 35-39 years group was 90.74%, and that in the >40 years group was 90.32%.
Conclusion: Overall, NIPT detection in elderly pregnant women has excellent clinical application value in reducing the incidence of either birth defects or abortion caused by invasive chromosome examination.
Keywords: Non-invasive prenatal testing (NIPT); chromosomal aneuploidy; gestational age; pregnant women.
It is critical to diagnose foetal chromosome aneuploidy in time through prenatal screening to prevent birth defects. This study aimed to evaluate the value of non-invasive prenatal testing (NIPT) in prenatal screening of foetal aneuploidy-associated diseases at different gestational ages. A retrospective analysis based on NIPT screening data at a medical laboratory was performed. The results showed that the total positivity rate and total positive predictive value of trisomy 21, trisomy 18, and trisomy 13 in older pregnant women (≥35 years old) were significantly higher than those in younger pregnant women, and there was an increasing trend with increasing maternal ages. This study indicated that NIPT detection in elderly pregnant women has an excellent application value in clinical practice to reduce the incidence of birth defects and abortion caused by invasive chromosome examination.