Role of Nuchal Translucency in Detection and Management of Congenital Anomalies in First Trimester Sonography in Developing Countries

Abstract

Variation of Nuchal Translucency (NT) measurements with increasing Crown-Rump Length (CRL). To correlate Nuchal Translucency with pregnancy outcome and clinical assessment of newborn for congenital anomalies. Antenatal ultrasound scanning done on pregnant women with singleton pregnancies and the fetal NT thickness was measured between 11 weeks and 13 weeks 6 days of gestation. Ultrasound probe used for transabdominal scanning was curvilinear probe with frequency band width of 3.5-5MHz. During the 11-13+6 weeks scan, the foetal CRL, Nuchal translucency, any structural abnormalities in the foetus, uterine anomaly, adnexa, cervix and the internal os were noted. In our study, we have done NT scan from 11 - 13+6 weeks of gestation; the mean examination time of the NT scan was 87.97 (12weeks 3days) standard deviation (SD)= 4.832. Subject study with high NT is 186 (16.6%) with 98.6% accuracy of association with congenital anomalies. Subject study with low NT is 936 (83.4%) with 99.8% of the babies born with no congenital anomalies. NT measurements increase with increasing CRL and a false positive rate increases with increasing gestational age. There is a strong association with high NT values and congenital anomalies.