Purpose: There are some difference with birth weight and estimated fetal weight measured by ultrasonic equipment. It is difficult to compare with the accuracy of many ultrasonic types of equipment at same time. We measured fetal weight to three ultrasonic equipments with same purchase time and similar price and the accuracy of each equipment to estimated fetal weight were compared to the real birth weight after delivery.
Materials and Methods: 80 singleton pregnancies between 28 weeks’ and 42 weeks’ of gestation with normal amniotic fluid volume (AFI 5-20) were included in our study. Any case with fetal anomalies, twin pregnancy, and intrauterine fetal death were excluded. Each 30 cases of fetuses were measured fetal weight with three kinds of ultrasonic equipment, which were HDI 3000 (Advanced Laboratory Technology, Philips, USA; as A), SSD-5000 (Aloka Ltd. Japan; as B), and Accuvix (Medison Ltd. Korea; as C) and who was given birth to within a week after last measurement. One qualified sonographer, there being a clinical experience more than 2 years measured the fetal weight within one weeks of delivery and compared the difference between estimated fetal weight and birth weight using each equipment. The confidence of estimated value was compared among these three equipments by ANOVA.
Results: The average weight difference showed 253.5 grams in A, 174.6 grams in B, and 277.9 grams in C. The B showed the significant difference of measurement error between other two (p=0.006). The accuracy rate of 5%, 10% and 20% weight-difference were 40%, 20% and 40% in A, 70%, 23.3% and 6.7% in B and 40%, 33.3% and 20% in C. There were some difference to measurement errors among three equipments and B equipment was shown less measurement error than other two equipment (p<0.05). The discrepancy between the estimated and actual fetal weights was depended on the times of the measured and delivered day.
Conclusions: To understand the characteristics of each ultrasonic equipment minimize the measurement errors and raise the reliability of measurement values in relation to estimated fetal weight during gestation.