Reference chart for transverse cerebellar diameter in developing fetuses according to their gestational age in Indian population

Abstract

ObjectivesThe objective of the study was to develop reference chart and to evaluate the efficacy of transverse cerebellar diameter (TCD) as one of the fetal biometric parameters used in ultrasonography to determine gestational age in the Indian population. Also, in this study we compared our findings with similar studies done on different ethnic populations to check effect of different ethnicity, environmental and nutritional factors in development of TCD.DesignA retrospective cross‐sectional study.MethodIn this study routine antenatal check‐ups of 300 singleton pregnant women were done after obtaining ethical clearance from Institute Ethical Committee. Ultrasonographic measurements of various fetal biometric parameters were taken which included, biparietal diameter (cm), head circumference (cm), abdominal circumference (cm), femur length (cm) and transverse cerebellar diameter (cm). Reference chart with mean TCD for corresponding gestational age (GA) in weeks was developed and compared with results of similar other studies.ResultsStatistically significant correlation found between TCD and gestational age (R2=0.92, p=0.0006). Gradually increasing linear pattern obtained between the development of TCD and corresponding gestational age of the fetus. Therefore, it is more reliable parameter to be used in regression formulae used in USG machine to predict accurate gestational age of fetus. When reference charts for TCD is compared with findings in other studies in different ethnic population, it is found that there is statistically significant difference exists.ConclusionsIn normally developing fetuses the TCD has linear correlation with advancing gestational age. Therefore, along with other fetal biometric parameters measurement TCD can be used in determination of gestational age for more accuracy. Thus by preventing over or under estimation of gestational age will help in reducing no judicious use of health resources and medical interventions. A separate reference chart is required for every different population because ethnicity, nutrition and environmental factors can have impact on normal TCD values. This will help to avoid misinterpretation of data to determine gestational age in various ethnic populations.