The Comparison of the Diagnostic Value of Fetal Foot length Measurement with the length of Femur and Fetal biparietal Diameter in Determining the Gestational Age

Document Type : Original Article


1 Assistant Professor of Radiology, Faculty of Medicine, Islamic Azad University, Mashhad, Iran

2 Assistant Professor of surgery, Faculty of Medicine, Islamic Azad University, Mashhad, Iran

3 Resident of Obstetrics & Gynecology, Mashhad University of Medical Sciences, Mashhad, Iran

4 MD, Mashhad, Iran


Introduction: Accurate estimating of the gestational age is one of the most important assesments during pregnancy. Various strategies for management of pregnancy depend on the estimation of accurate gestational age. In addition to the clinical methods, sonographic measurements are important to estimate the gestational age. The aim of this study was to compare the fetal foot length diameter as a non-traditional sonographic measurement with the biparietal diameter (BPD) and femur length (FL) to determine the gestational age in the second and third trimesters.
Methods and Material: This study was carried out on 150 pregnant women in second and third trimesters that referred to 22nd Bahman hospital affiliated to Islamic Azad University of Medical Sciences, in Mashad during 2006-2007 for sonographic evaluation. They had all regular menstruations. Non-random sampling was done until enough cases were collected to meet the desired sample size. Ultrasonography of pelvis and abdomen was performed by a single radiologist and the gestational age was reported based on the foot length, BPD, and FL separately. The history of the last menstrual period (LMP) was obtained as well. The protocol of the study was approved by the ethical board of the university and written informed consents were obtained from the patients. All collected data were analyzed by using SPSS software (14th version) and Fischer test.
Results: In the second trimester the accuracy of measuring fetal foot length was a little higher than fetal BPD and FL for estimation of gestational age (p=0.945). In the third trimester the measurement of fetal foot length and FL was a little more precise than BPD but there was no significant difference (p=0.961).
Conclusion: Estimation of the gestational age in the second and third trimester by measuring the fetal foot length was almost equivalent with the fetal BPD and FL.


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