scholarly journals Predicting fetal weight by three-dimensional limb volume ultrasound (AVol/TVol) and abdominal circumference

2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Li Kang ◽  
Qing-Qing Wu ◽  
Li-Juan Sun ◽  
Feng-Yun Gao ◽  
Jing-Jing Wang
2021 ◽  
Author(s):  
Xining Wu ◽  
Zihan Niu ◽  
Zhonghui Xu ◽  
Yuxin Jiang ◽  
Yixiu Zhang ◽  
...  

Abstract Background: Accurate estimation of fetal weight is important for prenatal care and for detection of fetal growth abnormalities. Prediction of fetal weight entails the indirect measurement of fetal biometry by ultrasound that is then introduced into formulae to calculate the estimated fetal weight. The aim of our study was to evaluate the accuracy of the automated three-dimensional(3D) fractional limb volume model to predict fetal weight in the third trimester.Methods: Prospective 2D and 3D ultrasonography were performed among women with singleton pregnancies 7 days before delivery to obtain 2D data, including fetal biparietal diameter, abdominal circumference and femur length, as well as 3D data, including the fractional arm volume (AVol) and fractional thigh volume (TVol). The fetal weight was estimated using the 2D model and the 3D fractional limb volume model respectively. Percentage error = (estimated fetal weight - actual birth weight) ÷ actual birth weight × 100. Systematic errors (accuracy) were evaluated as the mean percentage error (MPE). Random errors (precision) were calculated as±1 SD of percentage error.Results: Ultrasound examination was performed on 56 fetuses at 39.6 ± 1.4 weeks gestation. The average birth weight of the newborns was 3393 ± 530 g. The average fetal weight estimated by the 2D model was 3478 ± 467 g, and the MPE was 3.2 ± 8.9. The average fetal weights estimated by AVol and TVol of the 3D model were 3268 ± 467 g and 3250 ± 485 g, respectively, and the MPEs were -3.3 ± 6.6 and -3.9 ± 6.1, respectively. For the 3D TVol model, the proportion of fetuses with estimated error ≤ 5% was significantly higher than that of the 2D model (55.4% vs. 33.9%, p < 0.05). For fetuses with a birth weight < 3500 g, the accuracy of the AVol and TVol models were better than the 2D model (-0.8 vs. 7.0 and -2.8 vs. 7.0, both p < 0.05). Moreover, for these fetus, the proportions of estimated error ≤ 5% of the AVol and TVol models were 58.1% and 64.5%, respectively, significantly higher than that of the 2D model (19.4%) (both p < 0.05). The consistency of different examiners measuring fetal AVol and TVol were satisfactory,with the intraclass correlation coefficients of 0.921 and 0.963, respectively.Conclusion: In this cohort,the automated 3D fractional limb volume model improves the accuracy of weight estimation in most third-trimester fetuses. In particular, the 3D model estimation accuracy for fetuses with weight < 3500 g is significantly higher than that of the traditional 2D model.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xining Wu ◽  
Zihan Niu ◽  
Zhonghui Xu ◽  
Yuxin Jiang ◽  
Yixiu Zhang ◽  
...  

Abstract Background Accurate estimation of fetal weight is important for prenatal care and for detection of fetal growth abnormalities. Prediction of fetal weight entails the indirect measurement of fetal biometry by ultrasound that is then introduced into formulae to calculate the estimated fetal weight. The aim of our study was to evaluate the accuracy of fetal weight estimation of Chinese fetuses in the third trimester using an automated three-dimensional (3D) fractional limb volume model, and to compare this model with the traditional two-dimensional (2D) model. Methods Prospective 2D and 3D ultrasonography were performed among women with singleton pregnancies 7 days before delivery to obtain 2D data, including fetal biparietal diameter, abdominal circumference and femur length, as well as 3D data, including the fractional arm volume (AVol) and fractional thigh volume (TVol). The fetal weight was estimated using the 2D model and the 3D fractional limb volume model respectively. Percentage error was defined as (estimated fetal weight - actual birth weight) divided by actual birth weight and multiplied by 100. Systematic errors (accuracy) were evaluated as the mean percentage error (MPE). Random errors (precision) were calculated as ±1 SD of percentage error. The intraclass correlation coefficient (ICC) was used to analyze the inter-observer reliability of the 3D ultrasound measurements of fractional limb volume. Results Ultrasound examination was performed on 56 fetuses at 39.6 ± 1.4 weeks’ gestation. The average birth weight of the newborns was 3393 ± 530 g. The average fetal weight estimated by the 2D model was 3478 ± 467 g, and the MPE was 3.2 ± 8.9. The average fetal weights estimated by AVol and TVol of the 3D model were 3268 ± 467 g and 3250 ± 485 g, respectively, and the MPEs were − 3.3 ± 6.6 and − 3.9 ± 6.1, respectively. For the 3D TVol model, the proportion of fetuses with estimated error ≤ 5% was significantly higher than that of the 2D model (55.4% vs. 33.9%, p < 0.05). For fetuses with a birth weight < 3500 g, the accuracy of the AVol and TVol models were better than the 2D model (− 0.8 vs. 7.0 and − 2.8 vs. 7.0, both p < 0.05). Moreover, for these fetuses, the proportions of estimated error ≤ 5% of the AVol and TVol models were 58.1 and 64.5%, respectively, significantly higher than that of the 2D model (19.4%) (both p < 0.05). The inter-observer reliability of measuring fetal AVol and TVol were high, with the ICCs of 0.921 and 0.963, respectively. Conclusion In this cohort, the automated 3D fractional limb volume model improves the accuracy of weight estimation in most third-trimester fetuses. Prediction accuracy of the 3D model for neonatal BW, particularly < 3500 g was higher than that of the traditional 2D model.


2009 ◽  
Vol 20 (4) ◽  
pp. 269-281 ◽  
Author(s):  
EDUARD GRATACÓS ◽  
ELISENDA EIXARCH ◽  
FATIMA CRISPI

Selective fetal growth restriction (sFGR) has been reported to occur in about 10–15% of monochorionic (MC) twins. The diagnosis of sFGR has been based on variable criteria including estimated fetal weight (EFW), abdominal circumference and/or the degree of fetal weight discordance. Recent studies tend to use a simple definition which includes the presence of an EFW less than the 10th percentile in the smaller twin. Some would argue that the intertwin fetal weight discordance should be included in the definition. Indeed this factor plays a major role in the complications presented by these cases. While the majority of cases with one fetus below the 10th percentile usually will also present with a large intertwin EFW discordance, the contrary is not always true. Thus, it is possible to find MC twins with remarkable intertwin EFW discordance but the EFW of both fetuses are still within normal ranges. Although it appears to be common sense that a large intertwin discrepancy might represent a higher risk for some of the complications described later in this review, there is no consistent evidence to support this notion. Therefore, due to its simplicity, a definition based on an EFW below 10th percentile in one twin is probably the most useful for clinical and research purposes.


Radiology ◽  
2002 ◽  
Vol 223 (3) ◽  
pp. 661-665 ◽  
Author(s):  
Simona M. E. Boito ◽  
Jacqueline A. M. Laudy ◽  
Piet C. Struijk ◽  
Theo Stijnen ◽  
Juriy W. Wladimiroff

2016 ◽  
Vol 65 (3) ◽  
pp. 12-17
Author(s):  
Viktor A Mudrov

Selection of the optimal tactics of pregnancy and childbirth significantly depends on the expected volume of amniotic fluid. The amount of amniotic fluid reflects a condition of a fetus and changes at pathological conditions of both a fetus, and an uteroplacental complex. The aim of the study was a modification of methods for determining the expected volume of amniotic fluid. On the basis of maternity hospitals Trans-Baikal Region in the years 2013-2015 was held retrospective and prospective analysis of 300 labor histories, which were divided into 3 equal groups: 1 group - pregnant women with a body mass index (BMI) for Quetelet less than 24, Group 2 - with a BMI from 24 to 30, group 3 - with a BMI more than 30. In order to determine the expected volume of amniotic fluid were used the subjective method, the Chamberlain’s and Phelan’s methods. The error in determining volume of amniotic fluid by the existing methods exceeds 10 %, that defined need of creation of a quantitative method. On the basis of mathematical and 3d-modeling of the volume of amniotic fluid and fetal weight determined pattern change, which is expressed by the formula: VAF = IAF × М × π / GA2, where IAF - index of amniotic fluid (mm), M - fetal weight (g), GA - gestational age (weeks). Through a comprehensive analysis of anthropometric research of the pregnant women defined formula’s volume of amniotic fluid: V = 0,017 × HUF × (AC - 25 × BMI / GA)2 - М, where GA - gestational age (weeks), AC - abdominal circumference of the pregnant women (cm), BMI - body mass index for Quetelet in the first trimester of pregnancy (kg/m2), HUF - height of an uterine fundus (cm), M - the estimated fetal weight (g). In calculating volume of amniotic fluid according to the proposed ultrasonic formula error does not exceed 5,3 %, anthropometric formula error does not exceed 10,2 %. Thus, the method has a smaller error compared to the standard, and can be used to reliably determine volume of amniotic fluid in II and III trimester of pregnancy.


2005 ◽  
Vol 58 (11-12) ◽  
pp. 548-552 ◽  
Author(s):  
Ljiljana Mladenovic-Segedi ◽  
Dimitrije Segedi

Introduction Former investigations have shown that the accuracy of fetal weight estimation is significantly higher if several ultrasonic fe?tal parameters are measured, because the total body mass depends on the size of fetal head, abdominal circumference and femur length. The aim of this investigation was to establish the best regression model, that is a number of combinations of fetal parameters providing the most accurate fetal weight estimation in utero in our population. Material and methods This prospective study was carried out at the Gynecology and Obstetrics Clinic of the Clinical Center Novi Sad. It included 270 pregnant women with singleton pregnancies within 72 hours of delivery who underwent ultrasound measurements of the biparietal diameter (BPD), head circumference (HC), ab?dominal circumference (AC) and femur length (FL). Results In regard to fetal weight estimation formulas, the deviation was lowest using regression models that simultaneously analyzed four fetal parameters (0.55%) with SD ?7.61%. In these models the estimates of fetal weights were within ?5% of actual birth weight in 48.89%, and within ?10% of actual birth weight in 81.48%. Good results were also obtained using AC, FL measurements (0.92% ? 8.20) as well as using AC, HC, FL measurements (-1.45% ? 7.81). In our sample the combination of AC and FL model gave better results in fetal weight estimation (0.92 ? 8.20%) than the one using BPD and AC (2.97 ? 8.83%). Furthermore, the model using parameters AC, HC and FL showed a lower error in accuracy (-1.45 ? 7.81%) than the model using BPD, AC and FL (2.51 ? 7.82%). Conclusion This investigation has confirmed that the accuracy of fetal weight estimation increases with the number of measured ultra?sonic fetal parameters. In our population the greatest accuracy was obtained using BPD, HC, AC and FL model. In cases when fast estimation of fetal weight is needed, AC, HC, FL model may be appropriate, but if fetal head circumference cannot be measured (amnion rupture and/or fetal head already in the pelvis) the AC, FL model should be used.


2021 ◽  
pp. 1-3
Author(s):  
Sathyan Gnanasigamani ◽  
Sudhakar Vadivel ◽  
Bala Subramaniam ◽  
Sakthivel Raja Ganesan ◽  
Pradeebaa Thiyagarajan ◽  
...  

Background: The Accurate estimation of fetal weight is important in modern obstetrics. Currently, Hadlock's formula is used widely for fetal weight estimation, which includes BPD, AC, FL and HC. The correct plane of measurement of various standard parameters is difcult to obtain especially in third trimester. Hence soft tissue thicknesses of the fetus are tested for correlation with birth weight in this study. Materials & Methods: A prospective observational study conducted among 90 pregnant females referred for Ultrasound examination in the third trimester with an interval from the ultrasound scan to delivery of ≤7 days from 2019 to 2020. Results: The measurements of abdominal, fetal mid-thigh and mid-arm soft tissue thicknesses correlated well with birth weight in a high statistically signicant positive linear relationship. A new regression model developed out of the soft tissue thicknesses(FASTT, FMASTT, FTSTT) correlates better than the Hadlock's model and Sujitkumar Hiwale et al model (For Indian population) based on BPD, HC, AC and FL Conclusion: Ultrasound measurement of soft tissue thickness may prove to be a strong predictor of fetal weight essential for sonographic assessment of pregnancy. They are easy and simple hence fetal soft tissue thickness measurements, both two- and three-dimensional, may prove to be a diagnostic parameter that has as small an error rate as possible, is quick to use and reproducible by different examiners


Author(s):  
Shripad Hebbar ◽  
Sukriti Malaviya ◽  
Sunanda Bharatnur

Objective: The objective of the study was to find whether incorporation of MTSTT in fetal weight estimation formulae which are traditionally based on biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL) improves birth weight (BW) estimation. Methods: In a prospective observational study, MTSTT was measured within 1 week of delivery in 100 women with term singleton pregnancy along with other standard biometric parameters, i.e. BPD, HC, AC and FL, and MTSTT. Multiple regression analysis was carried out using PHOEBE regression software using different combinations of biometric variables to find out the best fit model of fetal weight estimation. The predicted BW was compared with actual neonatal BW soon after delivery and regression coefficients (R2) were determined for each of prediction models for comparing the accuracies. Results: Mean gestational age at delivery was 38.4±1.08 weeks and the BW of neonates varied between 2.18 kg and 4.38 kg (mean ± standard deviation: 3.07±0.43 kg). By adding MTSTT to BPD, HC, AC, and FL, we obtained the formula Log 10 (BW) = −0.14783+0.00725 *BPD +0.00043 *HC +0.00436 *AC +0.01942 *FL +0.16299 *MTSTT, which had a very good Pearson regression coefficient ((r2: 0.89 p<0.001) compared to conventional models based on standard fetal biometry. All prediction models had better strength of correlation when combined with MTSTT (p<0.001). The routine four parameter formula could identify 45% and 80% of fetuses within 5% and 10% weight range; pick up rate was further increased to 61% and 95% by addition of MTSTT. Conclusion: It is evident that addition of MTSTT to other biometric variables in models of fetal weight estimation improves neonatal BW prediction (r2=0.89).


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