The relationship between nuchal translucency thickening, abnormal blood flow spectrum of venous catheter and fetal chromosomal abnormalities

Abstract

Objective To explore the application value of fetal NT ultrasonography in fetal screening during early pregnancy. Methods We retrospectively analysed the outcomes of chromosome karyotype in 104 fetuses with increased nuchal translucency by invasive prenatal diagnosis in Guangzhou women and children′s medical center. To explore the relationship between abnormal NT thickness, abnormal blood flow spectrum of ducts venosus and chromosomal abnormalities. Results (1)Among 9980 pregnant women, there were 104 fetuses (about 1.0%) with abnormal NT thickness, the thickness of nuchal translucency was (3.7±1.2)mm. (2)Among 104 fetuses with abnormal NT thickness, 28 fetuses had abnormal chromosome karyotype, including 22 cases of chromosomal number abnormalities and 6 cases of structural abnormalities.The top three were trisomy 21, trisomy 18 and 47, XXX. (3)With the increase of NT thickness, the detection rate of chromosomal abnormalities increased accordingly.(4)The positive predictive values of NT thickening and normal blood flow spectrum of ductus venosus for chromosomal abnormalities were 20.93%. The positive predictive values of NT thickening and abnormal blood flow spectrum of ductus venosus for chromosomal abnormalities were 55.56%, the difference was statistically significant. Conclusion It is more effective to screen high-risk fetuses with abnormal chromosome karyotype by fetal NT ultrasonography, NT thickening and abnormal venous blood flow spectrum in early pregnancy. Key words: Transparent layer thickness; Venous blood flow spectrum; Chromosome aberrations