Objective: To determine the correlation of measuring fetal upper-arm and thigh volume using three-dimensional ultrasonography with weight estimation in large and small fetuses.
Material and Method: The authors included 46 pregnant women admitted for delivery in the Labor Room at Srinagarind Hospital, Khon Kaen University, between February 1 and September 30, 2004. Inclusion criteria were: 1) singleton pregnancy; 2) delivery within 48 hours after study; 3) estimation birthweight <� 2,500 g (small fetuses group: n = 22) or > 3,500 g (large fetus group: n = 24). All patients received two- and three-dimensional ultrasound examinations by an experienced practitioner. The upper-arm and thigh volume were assessed using a three-dimensional ultrasound scanner.
Results: In the large fetus group, upper-arm and thigh volume measurements by three-dimensional ultrasound strongly correlated with birthweight, r = 0.805 (95%CI = 0.594-0.912) and r = 0.739 (95%CI = 0.478-0.880), respectively. In the small fetuses group, the upper-arm and thigh volume measurements, by three-dimensional ultrasound, strongly correlated with birthweight, r = 0.868 (95%CI = 0.689-0.946) and r = 0.835 (95%CI = 0.638-0.929), respectively.
Conclusion: Upper-arm and thigh volumes measured by three-dimensional ultrasound highly correlates with weight estimation in large and small fetuses and can be used as a new modality for estimating fetal weight.
Keyword : Upper-arm volumes, Thigh volumes, Birthweight estimation by three-dimensional ultrasound, Large fetuses and small fetuses