Comparison of abdominal palpation, Johnson’s technique and ultrasound in the estimation of fetal weight in Northern Iran

Objectivesto assess the accuracy of abdominal palpation, Johnson's technique and ultrasound in the estimation of fetal weight (EFW).Design, setting and participants174 pregnant women were recruited at random in a large teaching hospital in Iran. Fetal weight was estimated by palpation and Johnson's technique at the time of admission by one qualified midwife, and then estimated by ultrasound by one radiologist. After birth, all newborns were weighed using the same scale.Findingsa significant correlation was found between EFW by ultrasound, palpation and Johnson's technique and actual birth weight. The differences between EFW by palpation, ultrasound and Johnson's technique and actual birth weight were significant for small-for-gestational-age fetuses (p<0.05, p<0.01 and p<0.001, respectively), but not for appropriate-for-gestational-age fetuses. These differences were significant for ultrasound (p<0.001) and palpation (p<0.05) in large-for-gestational-age fetuses. The sensitivity of ultrasound for EFW of low-birthweight fetuses (72.2%) and the sensitivity of Johnson's technique for EFW of normal-weight and macrosomic fetuses (97.3% and 75%, respectively) appeared to be higher than the sensitivities of the other methods.Conclusionpalpation and Johnson's technique can be used as alternatives to ultrasound for EFW, particularly if the measurements are taken by experienced, skilled personnel.