Journal of Dr. NTR University of Health Sciences (Jan 2019)

Fetal transcerebellar diameter to abdominal circumference ratio (TCD/AC) and to femur length ratio (TCD/FL) in the assessment of normal fetal growth

  • Karumanchi Ashok Hussain,
  • Silpa Kadiyala,
  • Amancharla Yadagiri Lakshmi,
  • Manchala Hindumathi

DOI
https://doi.org/10.4103/JDRNTRUHS.JDRNTRUHS_2_19
Journal volume & issue
Vol. 8, no. 1
pp. 5 – 10

Abstract

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Context: Intrauterine growth retardation (IUGR) is a major risk factor for perinatal mortality and morbidity, and its early detection is useful in deciding frequency of antenatal surveillance, optimal delivery timing, and early neonatal management to avoid perinatal mortality and morbidity. Most of the parameters for detection of IUGR are gestational age dependent. Transcerebellar diameter to abdominal circumference ratio (TCD/AC) is a gestational age independent parameter. IUGR due to uteroplacental insufficiency can present as isolated femur length reduction. So, transcerebellar diameter to femur length ratio (TCD/FL) can be useful in early detection of IUGR. Aims: To evaluate the accuracy of TCD/AC and utility of TCD/FL in normal pregnancy at varying periods of gestation and to derive a cut-off value for assessment of fetal growth. Materials and Methods: In this prospective study, 200 patients with cumulative ultrasound age (CUA) between 14-40 weeks. Routine ultrasound parameters and transcerebellar diameter were measured. TCD/AC and TCD/FL was calculated in all patients and for individual subgroups formed according to CUA. Statistical Analysis: Mean and standard deviation, 3rd, 50th and 97th percentile for TCD/AC and TCD/FL was determined for all patients to determine age specific cut off values. Relationship between continuous variables is studied using correlation and simple regression. Results: In our study, TCD with AC and FL show strong correlation throughout pregnancy. TCD/AC dispersed normally with mean value of 14.013 and SD of 0.738 and cut off value is 15.49. TCD/FL is dispersed normally throughout pregnancy with mean value 64.592 and SD of 3.998. TCD/AC, TCD/FL in subgroups also shows similar mean and SD as compared to entire study population. Conclusion: A cut off value of mean +/- SD (15.49), (72.588) for TCD/AC and TCD/FL could be used as a growth parameter for detection and determine the severity of IUGR.

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