Abstract
OBJECTIVE: To explore the clinical application of fetal nuchal translucency (NT) combined with noninvasive prenatal testing (NIPT) in screening for fetal chromosomal diseases. METHODS: A retrospective analysis was performed on NIPT results, prenatal diagnoses, and pregnancy outcomes of early pregnant women with enlarged NT at our center from 01/07/2018 to 01/01/2021. To ensure data integrity and minimize extraction bias, phased data access was adopted: the first batch of data was extracted from 01/07/2019 (start of Phase 1) to 20/07/2019 (end of Phase 1), covering participants examined from 01/07/2018 to 30/06/2019; the second batch was extracted from 01/02/2020 (start of Phase 2) to 20/02/2020 (end of Phase 2), including participants examined from 01/07/2019 to 01/01/2020. Chi-square tests were used to compare the incidence of fetal chromosomal abnormalities between the enlarged NT and normal NT groups, as well as among the subgroups of enlarged NT. RESULTS: Out of 48,130 women screened by NIPT, 774 had enlarged NT (≥2.5 mm); among these, 85 were classified as high-risk, and 72 underwent invasive diagnosis, resulting in 64 positive cases (including 42 cases of trisomy 21, among others). The thickening of NT was correlated with a higher detection rate of abnormalities, which was statistically significant. Among the 689 cases of enlarged NT with low-risk NIPT results, 20 were lost to follow-up, 5 terminated their pregnancies, while the others had healthy live births. CONCLUSION: Early pregnancy NT combined with NIPT demonstrates a high predictive value for fetal chromosomal abnormalities and holds significant importance for clinical pregnancy guidance.