Use of ultrasound fetal shoulder soft tissue thickness measurement in estimation of fetal weight

Abstract

Aims Birth weight (BW) estimation with ultrasound is of great importance in delivery decision and management of complications of delivery. The aim was to evaluate the effect of femur, humerus, and clavicular soft tissue thickness on BW and developed a formula for proper estimation of fetal weight. Methods This prospective cohort study, included 231singleton pregnancies, with 34 and 42 weeks of gestation, delivered within 48 h after ultrasound examination. In addition to four biometric ultrasound measures, shoulder soft tissue thickness, thigh and arm soft tissue thickness were measured from outer margin of skin to outer margin of bone shaft by same investigator. Spearman correlation test was used to assess correlations between soft tissue thickness measurements and BW. Linear regression model was used and R2 to test accuracy of the new formula. Results The mean humerus soft tissue thickness (HSTT) was 12 ± 3.5 mm (6–23.9 mm), mean femur soft tissue thickness (FSTT) was 15.9 ± 3.8 mm (7.3–32 mm), mean clavicular soft tissue thickness (CSTT) was 12.9 ± 3.2 mm (7.3–24 mm). There was a low correlation between BW and FSTT (r = 0.21, p = 0.001) and CSTT (r = 0.18, p = 0.005). Best fit formula was Log (BW) = −5697 + 7.2 (HC) + 15.3 (AC) + 22.6 (FL) + 17 (CSTT), was significantly correlated with BW (R2 = 0.60). Conclusion BW increased as the ultrasound shoulder soft tissue thickness increased. Adding soft tissue thickness measurements to fetal biometry is similar in terms of estimating fetal weight from the existing estimated fetal weight formula.

A predictive model of macrosomic birth based upon real-world clinical data from pregnant women

“…The most objective method currently employed to estimate fetal body weight is ultrasonographic (US) measurement which encompasses over 30 different formulas for the US estimates to predict newborn birth weight [16][17][18] , with the most widely used being the Hadlock formula 19 . To generate sonographic fetal weight estimations with a lower error margin, many formulas have re ected disparate parameters of the fetus (fetal abdominal fat layer 20 , shoulder soft-tissue thickness 21 , biacromial diameter 22 ), and some have even entailed 3D sonographic measurements 23 . Although such formulas and novel predictors may improve the accuracy of US evaluation, they nevertheless increase technical di culty and sonication time.…”

A predictive model of macrosomic birth based upon real-world clinical data from pregnant women

“…The most objective method currently employed to estimate fetal body weight is ultrasonographic (US) measurement, which encompasses over 30 different formulas for the US estimates to predict newborn birth weight [16][17][18], with the most widely used being the Hadlock formula [19]. To generate sonographic fetal weight estimations with a lower error margin, many formulas have reflected disparate parameters of the fetus (fetal abdominal fat layer [20], shoulder soft-tissue thickness [21], biacromial diameter [22]), and some have even entailed 3D sonographic measurements [23]. Although such formulas and novel predictors may improve the accuracy of US evaluation, they nevertheless increase technical difficulty and sonication time.…”

Establishing Chinese Fetal Growth Standards: Why and How

“…validated Scioscia's formula and proposed a modified one, both of which were considered equally efficient in calculating true fetal weight. For macrosomia or diabetic gestations, the utility of STT was valuable 62,63 . Garabedian et al 63 .…”

“…For macrosomia or diabetic gestations, the utility of STT was valuable. 62,63 Garabedian et al 63 showed that soft tissue in the upper arm had the best area under receiver operating characteristic (AUROC) value (0.855) along with good sensitivity and specificity (85.7% and 80.0%, respectively) for detecting macrosomia in pregnancies complicated by diabetes.…”

“…58,59 Measurement of soft-tissue thickness (STT), involving adipose tissue plus lean mass, has shown an advantage over conventional biometric parameters in weight prediction. [60][61][62] Most of the conventional measurements do not account for increased soft tissue mass, which may give rise to an underestimation of fetal weight. 60 In addition, measurement of mid-thigh STT demonstrated its superiority over head measurements when the fetal head is in a low position in the pelvis.…”