Ultrasound Detection of Fetal Structural Anomalies during First Trimester Nuchal Translucency Scan in Conjunction with Traditional 18–22 Weeks Anomaly Scan

a detailed examination of the fetus for structural anomalies as a part of routine ultrasound scan in a two stage screening process in the general obstetric population. Detection of Fetal Structural Anomalies during First Trimester Nuchal Translucency Scan in Conjunction with Traditional 18–22 Weeks Anomaly Scan. Int Aim and objective: The purpose of this study is to assess the value of performing a detailed examination of the fetus for structural anomalies in a two stage screening process at first trimester nuchal translucency (NT) scan and mid trimester anomaly scan in general population. Materials and methods: An observational study was conducted on 400 pregnant females referred to Department of Radiodiagnosis and Imaging in our hospital for NT scan at 11–13+6 weeks of gestational age. All women enrolled in the study were again subjected to traditional 18–22 weeks anatomy scan on follow up. Results: In our study, total 400 pregnant women were enrolled. Overall congenital anomaly prevalence in study population was 6.7%. Out of which 66.6% anomalies were detected in first trimester. While 35.7% of the anomalies were detected in second trimester anomaly scan. Combined use of NT and second trimester scan detected almost all of the congenital anomalies. However, many of the total anomalies among them were detected earlier in first trimester NT scan. Conclusion: Early scan can be very helpful in early diagnosis of fetal anomalies. But as many abnormalities cannot be evident in early pregnancy due to ongoing fetal development, second trimester anomaly scan should also be performed along with early screening as two stage screening process.