Tactile versus ultrasound estimation of fetal weight in late pregnancy

Abstract EN

Methods of fetal weight assessment include both tactile and ultrasonography.

The mean percent difference of zoographically predicted birth weight ranges from 6 to 15 %.

And it varies in the presence of different pregnancy complications such as fetal growth restriction and fetal microsomal.

Aim of the work: to compare the relative accuracy of tactile versus sonographer fetal weight estimation among singleton term parturient.

Patients : One hundred and fourteen singleton pregnant women fulfilling the inclusion criteria of the study were admitted for planned delivery at term (between 37-42 weeks) either by elective caesarean section with different obstetric indications (mostly for previous caesarean section) or by induction of labor and normal vaginal delivery.

Methods : fetal weight estimation during the first stage of normal labor or within 24 hours before elective caesarean section by two approaches each was blinded from the other and documented.

Results : overall the percentage of ultrasound estimates that were within ± 10 % of actual birth weight (70.1 %) was slightly higher than those of clinical estimates (66.6 %), but the difference was not statistically significant.

In the low birth weight group (£ 2500 gms) the mean error of ultrasonic estimation was significantly smaller than those of clinical estimation and the percentage of estimates within ± 10 % of actual birth weight was higher for the ultrasonic method.

In the high birth weight (> 4000 gms) The mean error of the clinical estimation was slightly smaller than those of ultrasonic estimations and a higher percentage of estimates within ± 10 % of actual birth weight with the prior.

Conclusion : the role of sonographer estimation of fetal weight becomes valuable only when the clinically estimated weight is less than 2500 gram ; where ultrasound is probably more accurate for fetal weight prediction, in addition to its other diagnostic benefits.