Abstract:

Objective: To explore the application and clinical value of the combined examination of NT thickening and nasal bone loss in the early prenatal（11~13+6 weeks）ultrasound screening. Methods: From January 2016 to May 2017, 5 637 cases of effective single fetus were obtained from early prenatal screening in Yijishan Hospital. A comparative analysis was made between the observation of NT thickening（≥2.5 mm）and nasal bone loss by abdominal color Doppler ultrasound and chromosome karyotype analysis in combination with postnatal follow-up. Results: In the 5 637 cases, there were 131 cases with nasal bone loss and / or NT thickening, 86 cases with NT thickening, and 55 cases with an absent nasal bone of which there were 10 cases with NT thickness combined with absence of nasal bone. The abnormal rate of chromosome abnormalities in NT was 11.62%, and the normal chromosome abnormalities rate of NT was 0.25%. When compared, the significant difference was P< 0.01. The abnormal rate of chromosome in the nasal bone loss was 23.63%, and the chromosomal abnormality was 0.39% in the nasal bone. When compared, the significant difference was P< 0.01. 7 cases of chromosomal abnormalities were found in the absence of nasal bone and NT thickeness, and the rate of examination was 70%. Conclusion: Nasal bone loss and NT thickening are important indexes of early prenatal ultrasound screening of chromosomal abnormalities with clinical significance of trisomy 21.

Key words: nuchal translucency, nasal bone, chromosome, structure, ultrasound screening of the first trimester