Effect of maternal age on foetal chromosomal defects: an investigation based on non-invasive prenatal testing

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.