Determination of Fetal Gestational Age by Ultrasonographic Measurement of Fetal Humeral Length among Patients Seen at a Tertiary Government Hospital: A Preliminary Study

Abstract

This study was done to determine fetal gestational age by ultrasonographic measurements of fetal humerus. Data collection will serve as initial database for the construction of intrauterine fetal growth chart using this parameter. This study also evaluated the strength of correlation of fetal age by humeral length (HL) measurement with menstrual age and compared with that of biparietal diameter (BPD) and femur length (FL). A cross-sectional study was done on 335 uncomplicated pregnant patients at gestational ages 20-40 weeks by conducting routine fetal biometrics including measurement of the fetal HL to determine fetal age. Its correlation with menstrual age was evaluated. Results were compared with that of BPD and FL and were plotted against age of gestation by last normal menstruation. Analyses of the data were done using SPSS version 10. HL showed a direct correlation coefficient of 0.918 compared to BPD (0.943) and FL (0.924). The combination of BPD, HL and FL increased the correlation to 0.951. While combination of the BPD and HL have the same correlation coefficient of 0.951. HL can be used as a reliable alternative parameter for estimating GA. The study also indicates that combination of BPD and HL is more accurate in predicting GA than any single parameter and as accurate when BPD and HL and FL parameters were used.