Association of maternal risk factors with fetal aneuploidy and the accuracy of prenatal aneuploidy screening: a correlation analysis based on 12,186 karyotype reports

BackgroundNIPT is becoming increasingly important as its use becomes more widespread in China. More details are urgently needed on the correlation between maternal risk factors and fetal aneuploidy, and how these factors affect the accuracy of prenatal aneuploidy screening. Methods Information on the pregnant women was collected, including maternal age, gestational age, specific medical history and results of prenatal aneuploidy screening. Additionally, the OR, validity and predictive value were also calculated. Results A total of 12,186 analysable karyotype reports were collected with 372 (3.05%) fetal aneuploidies, including 161 (1.32%) T21, 81 (0.66%) T18, 41 (0.34%) T13 and 89 (0.73%) SCAs. The OR was highest for maternal age less than 20 years (6.65), followed by over 40 years (3.59) and 35-39 years (2.48). T13 (16.95) and T18 (9.40) were more frequent in the over-40 group (P < 0.01); T13 (3.62/5.76) and SCAs (2.49/3.95) in the 35-39 group (P < 0.01). Cases with a history of fetal malformation had the highest OR (35.94), followed by RSA (13.08): the former was more likely to have T13 (50.65) (P < 0.01) and the latter more likely to have T18 (20.50) (P < 0.01). The sensitivity of primary screening was 73.24% and the NPV was 98.23%. The TPR for NIPT was 100.00% and the respective PPVs for T21, T18, T13 and SCAs were 89.92, 69.77, 53.49 and 43.24%, respectively. The accuracy of NIPT increased with increasing gestational age (0.81). In contrast, the accuracy of NIPT decreased with maternal age (1.12) and IVF-ET history (4.15). Conclusions 1Pregnant patients with maternal age below 20 years had higher risk of aneuploidy, especially in T13; A history of fetal malformations is more risky than RSA, with the former more likely to have T13 and the latter more likely to have T18;3 Primary screening essentially achieves the goal of identifying a normal karyotype, and NIPT can accurately screen for fetal aneuploidy; 4A number of maternal risk factors may influence the accuracy of NIPT diagnosis, including older age, premature testing, or a history of IVF-ET. In conclusion, this study provides a reliable theoretical basis for optimizing prenatal aneuploidy screening strategies and improving population quality.

Automated summary

This study aims to investigate the correlation between maternal risk factors and fetal aneuploidy, as well as their impact on the accuracy of prenatal aneuploidy screening. The results showed that pregnant women below the age of 20 and above the age of 40 had a higher risk of fetal aneuploidy, with older women more likely to have T13 and T18 abnormalities. A history of fetal malformations was more likely to result in T18 abnormalities compared to recurrent spontaneous abortion. Primary screening successfully identifies normal karyotypes, while non-invasive prenatal testing accurately screens for fetal aneuploidy. Maternal risk factors such as age, premature testing, and a history of in vitro fertilization and embryo transfer (IVF-ET) may influence the accuracy of non-invasive prenatal testing diagnosis.