ULTRASONOGRAPHIC EVALUATION OF FETUS BETWEEN 11 TO 14 WEEKS OF GESTATIONAL AGE: A CROSS SECTION STUDY CONDUCTED IN A TERTIARY CARE HOSPITAL OF GUJARAT

Abstract

Background: Over the past decade, prenatal diagnosis has shifted rapidly from the second trimester into first trimester. The recent development of high frequency transvaginal ultrasound transducers has led to vastly improved ultrasound resolution and improved visualization of fetal anatomy earlier in gestation in 11 to 14 weeks of ultrasonographic scan. The early scan also provides reliable identification of chorionicity, which is the main determinant of outcome in multiple pregnancies.

Objectives: This study was conducted for diagnose or suspect a wide range of structural and chromosomal anomalies of fetus; investigate the complication of early pregnancy; confirm viability; accurately date the pregnancy and diagnosis of multiple pregnancy & determination of chorionicity & amnionicity.

Methods: Ultrasound screening transabdominally and transvaginally was performed at 11–14 weeks in randomly selected cases of 150 pregnant women who attended our hospital from September 2007 to September 2009.In present study, ultrasound machine of high accuracy was used. Ultrasound examination was performed transabdominally and transvaginally

Result: 45.45% structural anomalies were detected in 11 to 14 weeks USG scan, 36.36% structural anomalies were detected in 2^nd trimester (18-22 weeks) USG scan and 18.18% structural anomalies were detected postnatally. Incidence rates of structural anomalies detected in 11 to 14 weeks USG scan, 2^nd trimester USG scan and postnatally were 3.3%, 2.6% and 1.4% respectively with total incidence rate of 7.3%. Detection rate of structural anomalies in 11 to 14 weeks USG scan & combined USG scan was 71.42% & 81.8% respectively. Highest number of structural abnormalities that is 34%, detected in CNS; out of these, 100% of them had NTDs.

Conclusion: The concepts of first trimester scan solely to confirm viability or date of pregnancy should be abandoned and attempt should be made to visualize fetal anatomy in detail.