CORRELATION BETWEEN ABDOMINAL CIRCUMFERENCE AND CIRCUMFERENCE OF THE THIGH FOR CALCULATION OF FETAL WEIGHT IN FETUS WITHOUT ULTRASONOGRAPHIC EVIDENCE OF MALFORMATION

Abstract

Introduction: Fetal growth disorders are an important chapter of maternal-fetal pathologies and fetal weight estimation is of fundamental importance in the monitoring of obstetric situations associated with abnormal fetal growth. The serial ultrasound measurement of the fetal thigh circumference (CCx) has been shown to be an excellent parameter in the identification of deviations in fetal growth and fetal development after the second trimester of gestation. Objective: To search for a correlation between the waist circumference and the circumference of the fetal thigh, in view of the estimated fetal weight. Method: A cross-sectional, descriptive study was performed by assessing the waist circumference and the fetal thigh circumference, seeking a correlation between these parameters, in order to estimate the fetal weight. Results: A total of 75 pregnant women with a mean age of 24.7 years and multiple comorbidities were evaluated, most of whom were white and non-smokers. A positive correlation was observed in the evaluation of thigh circumference between examiners 1 and 2, but there was a significant difference between the fetal weights estimated by thigh circumference and abdominal circumference. Conclusion: There is a good correlation between abdominal circumference and fetal thigh circumference. The correction factor between the two measurements of 2.32, previously calculated by our group based on tables in the literature, proved to be reliable in this work, however it was shown that there is a significant change in this correlation after 32 weeks, requiring a correction factor to 2.10 after this gestational age. Fetal thigh measurement appears to be a reproducible and useful biometric parameter in fetuses with pathologies that prevent the measurement of abdominal circumference.