Fetal weight estimation by automated three-dimensional limb volume model in late third trimester compared to two-dimensional model: a cross-sectional prospective observational study

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.

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Fetal weight estimation by automated three-dimensional limb volume model in late third trimester compared to two-dimensional model: a cross-sectional prospective observational study

10.21203/rs.3.rs-271271/v1 ◽

2021 ◽

Author(s):

Xining Wu ◽

Zihan Niu ◽

Zhonghui Xu ◽

Yuxin Jiang ◽

Yixiu Zhang ◽

...

Keyword(s):

Birth Weight ◽

3D Model ◽

Three Dimensional ◽

Fetal Weight ◽

Percentage Error ◽

Limb Volume ◽

Third Trimester ◽

Volume Model ◽

Estimated Error ◽

2D Model

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.

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Discrepancy Analysis between Clinical Versus Ultrasound Estimated Fetal Weight and Actual Birth Weight at 3rd Trimester

Journal of Shaheed Suhrawardy Medical College ◽

10.3329/jssmc.v11i1.43176 ◽

2019 ◽

Vol 11 (1) ◽

pp. 32-38

Author(s):

Naznin Rashid Shewly ◽

Menoka Ferdous ◽

Hasina Begum ◽

Shahadat Hossain Khan ◽

Sheema Rani Debee ◽

...

Keyword(s):

Birth Weight ◽

Low Birth Weight ◽

Fetal Weight ◽

P Value ◽

Weight Estimation ◽

Third Trimester ◽

Mortality And Morbidity ◽

Fetal Weight Estimation ◽

Obstetric Management ◽

Estimated Fetal Weight

Background: In obstetric management fetal weight estimation is an important consideration when planning the mode of delivery in our day to day practice. In Bangladesh low birth weight is a major public health problem & incidence is 38% - 58%. Neonatal mortality and morbidity also yet high. So accurate antenatal estimation of fetal weight is a good way to detect macrosomia or small for date baby. Thus to improve the pregnancy outcome and neonatal outcome decreasing various chance of neonatal mortality and morbidity antenatal fetal weight prediction is an invaluable parameter in some situation where to identify the at risk pregnancy for low birth weight become necessary. Reliable method for prenatal estimation of fetal weight two modalities have got popularity - Clinical estimation and another one is ultrasonic estimation. This study was designed to determine the accuracy of clinical versus ultrasound estimated fetal weight detecting the discrepancy with actual birth weight at third trimester. So that we can verify more reliable and accurate method. Objectives: To find out more accurate and reliable modality of fetal weight estimation in antenatal period during obstetric management planning. To compare clinical versus ultrasound estimated fetal weight & to determine discrepancy of both variable with actual birth weight. Method: This prospective, cross sectional analytical study was carried out in Dhaka Medical College Hospital from January 2006 to December 2006. By purposive sampling 100 pregnant women fulfilling inclusion criteria were included in my study in third trimester (29wks-40wks). In clinical weight estimation procedure SFH (Symphysio Fundal Height) was measured in centimeter. On pervaginal finding whether vertex below or above the ischial spine was determined. By Johnson’s formula fetal weight in grams was estimated. Then by ultrasound scan different biometric measurements were taken and finally by Hadlock’s formula fetal weight was estimated. Eventually actual birth weight was taken after birth by Globe Brand weighing machine. Accuracy of both modalities were compared and which one was more reliable predictor was determined by statistical analysis. Results: After data collection were analyzed by computer based software (SPSS). There was gradual and positive relationship between symphysiofundal height and estimated birth weight. Discrepancy between clinical and actual birth weight at third trimester was statistically significant – Paired Student’s ‘t’ test was done where p value was <0.001. Whereas discrepancy between sonographically estimated fetal weight with actual birth weight was not statistically significant (by paired ‘t’ test where p value was >0.05). That implies discrepancy between ultrasound estimated fetal weight and actual birth weight was significantly less than that of clinically estimated fetal weight. 14% clinically and 46% sonographically estimated fetal weight were observed within £ 5% of actual birth weight. 31% clinical and 42% sonographically estimates observed within 6% to 10% of actual birth weight and 55% clinical and 12% sonographically estimate were >10% of actual birth weight. That is about 88% sonographical versus 45% clinical estimates were within 10% of actual birth weight. Conclusion: There is no doubt about importance of fetal weight in many obstetric situations. Clinical decisions at times depends on fetal weight. Whether to use oxytocin, to use forceps or vacuum for delivery or extend of trial or ended by Caesarian section immediately or no scope of trial to be largely depend on fetal size and weight. So more accurate modality for antenatal fetal weight estimation has paramount importance. In my study sonographically estimated weight have more accuracy than that of clinical estimate in predicting actual birth weight. Sonographically estimated fetal weight is more reliable, accurate and reproducible rather than other modality. J Shaheed Suhrawardy Med Coll, June 2019, Vol.11(1); 32-38

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“A NOVEL ATTEMPT IN ESTIMATION OF FETAL WEIGHT USING NEW SOFT TISSUE MEASUREMENTS”

10.36106/ijsr/0603062 ◽

2021 ◽

pp. 1-3

Author(s):

Sathyan Gnanasigamani ◽

Sudhakar Vadivel ◽

Bala Subramaniam ◽

Sakthivel Raja Ganesan ◽

Pradeebaa Thiyagarajan ◽

...

Keyword(s):

Birth Weight ◽

Soft Tissue ◽

Strong Predictor ◽

Three Dimensional ◽

Fetal Weight ◽

Ultrasound Measurement ◽

Accurate Estimation ◽

Tissue Thickness ◽

Third Trimester ◽

Soft Tissue Thickness

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

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Estimation of fetal weight by ultrasonography after preterm premature rupture of membranes: comparison of different formulas

Journal of Perinatal Medicine ◽

10.1515/jpm-2016-0258 ◽

2017 ◽

Vol 45 (2) ◽

Cited By ~ 2

Author(s):

Sertac Esin ◽

Mutlu Hayran ◽

Yusuf Aytac Tohma ◽

Mahmut Guden ◽

Ismail Alay ◽

...

Keyword(s):

Birth Weight ◽

Gestational Age ◽

Fetal Weight ◽

Percentage Error ◽

Weight Estimation ◽

Premature Rupture ◽

Preterm Premature Rupture ◽

Absolute Percentage Error ◽

The Mean ◽

Weight Groups

AbstractObjective:To compare different ultrasonographic fetal weight estimation formulas in predicting the fetal birth weight of preterm premature rupture of membrane (PPROM) fetuses.Methods:Based on the ultrasonographic measurements, the estimated fetal weight (EFW) was calculated according to the published formulas. The comparisons used estimated birth weight (EBW) and observed birth weight (OBW) to calculate the mean absolute percentage error [(EBW–OBW)/OBW×100], mean percentage error [(EBW–OBW)/OBW×100)] and their 95% confidence intervals.Results:There were 234 PPROM patients in the study period. The mean gestational age at which PPROM occured was 31.2±3.7 weeks and the mean gestational age of delivery was 32.4±3.2 weeks. The mean birth weight was 1892±610 g. The median absolute percentage error for 33 formulas was 11.7%. 87.9% and 21.2% of the formulas yielded inaccurate results when the cut-off values for median absolute percentage error were 10% and 15%, respectively. The Vintzileos’ formula was the only method which had less than or equal to 10% absolute percentage error in all age and weight groups.Conclusions:For PPROM patients, most of the formulas designed for sonographic fetal weight estimation had acceptable performance. The Vintzileos’ method was the only formula having less than 10% absolute percentage error in all gestational age and weight groups; therefore, it may be the preferred method in this cohort. Amniotic fluid index (AFI) before delivery had no impact on the performance of the formulas in terms of mean percentage errors.

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Clinical versus ultrasonographic fetal weight estimation and its correlation with actual birth weight

International Journal of Reproduction Contraception Obstetrics and Gynecology ◽

10.18203/2320-1770.ijrcog20190275 ◽

2019 ◽

Vol 8 (2) ◽

pp. 503

Author(s):

Ashwini Ingale ◽

Shweta Avinash Khade ◽

Sneha Shirodkar

Keyword(s):

Birth Weight ◽

Tertiary Care ◽

Mean Absolute Percentage Error ◽

Fetal Weight ◽

Percentage Error ◽

Care Hospital ◽

Weight Estimation ◽

Clinical Method ◽

Fetal Weight Estimation ◽

Absolute Percentage Error

Background: This is a prospective study was conducted at Obstetrics and Gynecology department, tertiary care Hospital, to compare the accuracy of clinical and ultrasonographic estimation of fetal weight at term with actual birth weight.Methods: The present study is a prospective comparative study of fetal weight estimation in Antenatal women with term gestation (37week to 42week of gestation) singleton pregnancy with vertex presentation, who had gestational age confirmed by dates and ultrasound scanning of< 22weeks admitted in tertiary care center from March 2016 to November 2016. Patients with Polyhydramnios, oligohydramnios, Antepartum hemorrhage, Congenital anomalies of fetus, Obese (Body mass index >30 kilogram/meter2) are excluded from the study. Estimation of fetal weight is done by clinical method and ultrasonography. Birth weight after delivery was recorded in grams by electronic weighing machine and tabulated.Results: Clinical as well as ultrasonography estimates observed to be strongly correlate with actual birth weight. Both the methods had more sensitivity in birth weight range 2500-4000gm than <2500g and >4000g. The overall mean absolute percentage error of the clinical method (7.2±7.7) was smaller than that of the sonographic method (16.2±11.1). In low birth-weight (<2,500g) group, mean absolute percentage error was 9.0±11.3 with USG and same with clinical was 11.7±9.0. No statistically significant difference was observed.Conclusions: The present study concludes that clinical estimation of birth-weight is as accurate as routine ultrasonographic estimation.Clinical palpation should be considered as diagnostic tool for FWE and is equally reliable even when done by trained medical person. It is cheap and easy to teach. The need is to practically apply this method in obstetrics and guide the management decisions.

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Feasibility of Sonography in estimating Fetal Weight of Low Birth Weight Babies

International Journal of Infertility & Fetal Medicine ◽

10.5005/jp-journals-10016-1126 ◽

2016 ◽

Vol 7 (2) ◽

pp. 42-48

Author(s):

Lavanya Rai ◽

Sanghamithra Reddy ◽

Shripad Hebbar

Keyword(s):

Birth Weight ◽

Absolute Error ◽

Fetal Weight ◽

Percentage Error ◽

Weight Estimation ◽

Validation Group ◽

Absolute Percentage Error ◽

Low Birth Weight Babies ◽

Formula Derivation ◽

New Formula

ABSTRACT Background Currently available ultrasound-based fetal birth weight estimation methods have been designed for a group of neonates with wide birth weight range and hence are faced with increased error of margin. Whenever there is a need for delivering pregnant woman with small fetus, prior knowledge of approximate fetal weight is of utmost importance for neonatal survival, and an error in this process can result in significant morbidity/mortality to the newborn baby. This necessitates need for the establishment of new birth weight formula exclusively for this subset of fetuses. Objectives To test the accuracy of established formulae in fetuses ≤ 2000 gm at birth in singleton pregnancies. To develop new formula for this group of small fetuses delivering in our institution with maximal accuracy and reliability and to prospectively validate this formula in subsequent set of pregnant cohort. Materials and methods The current study was done in two phases: The first phase was a formula derivation phase wherein the four major parameters [biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL)] were evaluated from a set of 128 postpartum women who delivered a neonate weighing ≤2 kg within 1 week of ultrasound examination. Stepwise regression analysis using birth weight as dependent parameter and fetal biometric parameters as independent parameters was used to develop the best formula for estimating fetal weight at birth. In the second phase (formula validation phase), the newly derived formula was tested for its accuracy in 31 pregnant women who gave birth to neonates weighing ≤2 kg. Results The new formula (log10 [BW] = 1.0131 + 0.0216 × HC + 0.0448 × AC + 0.2183 × FL + 0.0001 × BPD × AC – 0.0059 × AC × FL) was superior to established birth weight formulae. In the formula derivation group, the lowest mean ± standard deviation (SD) absolute error was 130 ± 91 gm and the lowest mean absolute percentage error was 9.8 ± 7% SD for the new formula and 61.7% of weight estimates fell within ± 10% of the actual weight at birth and this percentage further increased to 83.6 and 91.4% for error of margin of ±15 and ±20% respectively. When this formula was applied in the validation group, the absolute error in grams was 102 ± 115 and absolute percentage error was 7.4 ± 7; hence 77.4% fell within 10%, 80.6% fell within 15%, 90.3% fell within 20%. Further, in the validation group, mean ± SD of estimated birth weight was 1337 ± 406 gm, which was closest to actual birth weight (1328 ± 433 gm). Conclusion Our new formula is likely to estimate birth weight in small fetuses (≤2 kg) with reasonable accuracy and reliability. When compared to available methods of ultrasound birth weight estimation, absolute error and absolute percentage error is least with our formula indicating a good fit. How to cite this article Reddy S, Hebbar S, Rai L. Feasibility of Sonography in estimating Fetal Weight of Low Birth Weight Babies. Int J Infertil Fetal Med 2016;7(2):42-48.

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Accuracy of sonographic fetal weight estimation in a tertiary care hospital in Bharatpur, Nepal

Journal of College of Medical Sciences-Nepal ◽

10.3126/jcmsn.v12i4.16374 ◽

2017 ◽

Vol 12 (4) ◽

pp. 174-178 ◽

Cited By ~ 1

Author(s):

V Natraj Prasad ◽

Pratik Poudel ◽

Pramod Kumar Chhetry

Keyword(s):

Birth Weight ◽

Mean Absolute Percentage Error ◽

Fetal Weight ◽

Percentage Error ◽

Strong Positive Correlation ◽

Weight Estimation ◽

Positive Correlation ◽

Fetal Weight Estimation ◽

Absolute Percentage Error ◽

Estimated Fetal Weight

Background & Objectives: Among the various methods used in the estimation of intrauterine fetal weight, sonographic fetal weight estimation is the one and has become an important component of antenatal care. The study was conducted with objective to assess the accuracy and reliability of ultrasound estimation of fetal weight in women with a singleton term pregnancy. Materials & Methods: This was a prospective cross-sectional study of 120 women with singleton term pregnancies. Ultrasound estimated fetal weight was calculated by measuring the biparietal diameter and abdominal circumference. The estimated fetal weight was compared to the actual birth weight post delivery. The correlation between estimated fetal weight and actual birth weight was assessed by Pearson's correlation coefficient and the accuracy of sonographic fetal weight estimation was measured using mean error, mean absolute error, mean percentage error, mean absolute percentage error and proportion of estimates within 10% of actual birth weight. Results were tested at error level set at p ≤ 0.05.Results: Mean estimated and actual birth weights were 2863.5 ± 441.9 g and 2822.5 ± 407.7 g respectively. There was a strong positive correlation between estimated fetal weight and actual birth weight (r= 0.71, p <0.001). The mean percentage error and mean absolute percentage error of ultrasound fetal weight estimations were 1.9 ± 11.4% and 8.8 ± 7.5% respectively. Conclusion: Sonographically estimated fetal weight had strong positive correlation with actual birth weight and thus sonography can be used in the estimation of fetal weight for the better perinatal outcome.

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Accuracy of ultrasonic fetal weight estimation using head and abdominal circumference and femur length

Medicinski pregled ◽

10.2298/mpns0512548m ◽

2005 ◽

Vol 58 (11-12) ◽

pp. 548-552 ◽

Cited By ~ 1

Author(s):

Ljiljana Mladenovic-Segedi ◽

Dimitrije Segedi

Keyword(s):

Birth Weight ◽

Head Circumference ◽

Fetal Weight ◽

Abdominal Circumference ◽

Weight Estimation ◽

Fetal Head ◽

Total Body Mass ◽

Femur Length ◽

Fetal Weight Estimation ◽

Gynecology And Obstetrics

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.

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INTEGRATION OF FETAL MID THIGH SOFT TISSUE THICKNESS IN ULTRASOUND BIRTH WEIGHT ESTIMATION FORMULA INCREASES THE ACCURACY OF FETAL WEIGHT ESTIMATION NEAR TERM

Asian Journal of Pharmaceutical and Clinical Research ◽

10.22159/ajpcr.2018.v11i4.23776 ◽

2018 ◽

Vol 11 (4) ◽

pp. 446

Author(s):

Shripad Hebbar ◽

Sukriti Malaviya ◽

Sunanda Bharatnur

Keyword(s):

Birth Weight ◽

Prediction Models ◽

Fetal Weight ◽

Abdominal Circumference ◽

Estimation Methods ◽

Weight Estimation ◽

Singleton Pregnancy ◽

Fetal Biometry ◽

Fetal Weight Estimation ◽

Soft Tissue Thickness

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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