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

2017 ◽  
Vol 45 (2) ◽  
Author(s):  
Sertac Esin ◽  
Mutlu Hayran ◽  
Yusuf Aytac Tohma ◽  
Mahmut Guden ◽  
Ismail Alay ◽  
...  

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.

Author(s):  
Ashwini Ingale ◽  
Shweta Avinash Khade ◽  
Sneha Shirodkar

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.


2016 ◽  
Vol 7 (2) ◽  
pp. 42-48
Author(s):  
Lavanya Rai ◽  
Sanghamithra Reddy ◽  
Shripad Hebbar

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.


2017 ◽  
Vol 12 (4) ◽  
pp. 174-178 ◽  
Author(s):  
V Natraj Prasad ◽  
Pratik Poudel ◽  
Pramod Kumar Chhetry

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. 


2019 ◽  
Vol 4 (2) ◽  
pp. 83
Author(s):  
Isam Bsisu ◽  
Alaa Aldalaeen ◽  
Rawan Elrajabi ◽  
Ala AlZaatreh ◽  
Rama Jadallah ◽  
...  

<p><strong><em>Background:</em></strong><em> Preterm premature rupture of membranes (PPROM) is responsible for one?third of all preterm births worldwide. This aim of this study was to investigate the outcome of neonates born after prolonged PPROM with gestational age below 34 weeks. </em></p><p><strong><em>Materials and methods:</em></strong><em> This retrospective study included 65 patients who were born to mothers with Prolonged PPROM &lt;34 weeks gestation between January 2011 and December 2015 and admitted to the neonatal intensive care unit (NICU) at Jordan University Hospital. </em></p><p><strong><em>Results: </em></strong><em>The mean gestational age of included patients was (31.9 ± 2.5 weeks), mean birth weight was (1840 ± 583 g) and 43 (66.2%) were males. The mortality rate in those infants was 12.3 %. Gestational age, birth weight, and Apgar score were significantly lower among mortality cases compared to surviving cases (P &lt; 0.05). </em></p><p><strong><em>Conclusion:</em></strong><em> Prolonged PPROM before the 34<sup>th</sup> gestational week is associated with high rate of morbidity and mortality, for which early identification of risk factors for developing PPROM can help in reducing the risk for preterm labors and subsequent burden on healthcare system.</em></p>


Author(s):  
Nevin Tuten ◽  
Onur Guralp ◽  
Koray Gok ◽  
Abdullah Tuten ◽  
Altay Gezer

Objective: To investigate the accuracy of fetal weight estimation made by the last prenatal ultrasound measurement in low birth weight newborns (<2500 g). Study Design: A total of 1082 women were evaluated in this retrospective cohort study. Demographic and clinical information of the mother and newborn and obstetric ultrasonography measurements and findings performed in the last week before birth were recorded. Accuracy of fetal weight estimation and parameters affecting it was investigated. Results: Accurate estimation rates were lower in the term compared to the preterm delivery group; and in the SGA group compared to the AGA group (respectively, p=0.016, p=0.032). Accurate estimation rates (p=0.182) were comparable between the 500-1500 g and 1501-2500 g subgroups. The multiple linear regression analysis showed that gestational age at birth, birth weight, examination during labor, and duration between examination to delivery were statistically significant for the accurate estimation(p=0.001) Conclusions: Accurate estimation rates were lower in the term compared to the preterm delivery group, and in the SGA group compared to the AGA group. The factors affecting accurate estimation were found to be gestational age at birth, birth weight, examination during labor, and duration between examination to delivery.Keywords: Accurate estimation rate, Duration between examination to delivery, Examination during


Author(s):  
Sahin Onur Guralp ◽  
Nevin Tüten ◽  
Abdullah Tüten ◽  
Altay Gezer

<p><strong>Objective: </strong>To determine the factors indicating the accuracy of fetal weight estimation in the last prenatal ultrasonography before delivery in preterm newborns with normal amniotic fluid volume.</p><p><strong>Study Design: </strong>371 singleton pregnancies with normal amniotic fluid volume and delivered at between 24+0 and 37+0 weeks of gestation were evaluated in a retrospective study. Maternal and fetal demographic and clinical data, ultrasonographic measurements and findings were recorded. Any possible associations between the absolute percentage errorof fetal weight estimations and the maternal and fetal data were examined.<strong></strong></p><p><strong>Results: </strong>In 135 of the 371 women (36%), the absolute percentage errorwas greater than 10%. The mean absolute percentage errorwas 8.7±7.5%. The mean absolute percentage errorswere 4.1±2.7% and 16.8±6.4% in the accurate and inaccurate estimation groups, respectively.<strong></strong></p><p>There were no significant differences in age, body mass index (BMI), gestational age (GA) at delivery, estimated fetal weight (EFW), actual weight at birth, days from the last ultrasound examination to delivery, small for gestational age (SGA) rate, placenta localization or fetal presentation between the accurate and inaccurate estimation groups. The rate of women examined during labor was significantly higher in the inaccurate estimation group compared to the accurate estimation group. </p><p>The linear regression analysis showed that BMI (p=0.006), GA at delivery (p&lt;0.001), examination during labor (p&lt;0.001), and presence of SGA (p=0.004) were significant for the prediction of the absolute percentage error.</p><p>Standardized coefficients (β) showed that examination during labor (β=0.224) was the most important factor for the prediction of the absolute percentage error, followed by GA at delivery (β=-0.198), presence of SGA (β=-0.158), and BMI (β=0.142).</p><strong>Conclusion</strong>: In 36% of our study population, the absolute percentage error was &gt;10%. Examination during labor was the most important factor for the prediction of the absolute percentage error, followed by GA at delivery, presence of SGA, and BMI.


2017 ◽  
Vol 35 (08) ◽  
pp. 703-706
Author(s):  
Katherine Himes ◽  
Adriane Haragan

Objective Clinicians use estimated fetal weight (EFW) as a proxy for birth weight (BW) in the antenatal period. Our objective was to compare the accuracy of EFW obtained by ultrasound to BW among infants born during the periviable period and determine if accuracy of EFW varied among small for gestational age (SGA) versus appropriate for gestational age (AGA) grown neonates. Study Design We included women who delivered between 230/7 and 256/7 weeks' gestation and had an EFW within 7 days of delivery. Mean percentage difference and median absolute percentage difference between EFW and BW were calculated. Results Our cohort included 226 neonates with a mean gestational age of 241/7 ± 0.8 weeks and median BW of 653 g (interquartile range [IQR]: 580–750 g). The median absolute percentage difference between EFW and BW of fetal weight estimates was 9.2% (IQR: 3.6–17.2). EFW overestimated BW for 75% (n = 171) of the cohort. Among SGA infants, the mean percentage difference in EFW and BW was 16.2 ± 19.4% versus 6.9% ± 13.1% in AGA infants (p = 0.019). Conclusion EFW overestimated BW in this cohort. In addition, ultrasound was less accurate among infants born SGA. These data are important to consider when counseling families facing periviable delivery.


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.


2019 ◽  
Vol 35 (1) ◽  
Author(s):  
Emre Erdem Tas ◽  
Edip Alptug Kir ◽  
Gamze Yilmaz ◽  
Ayse Filiz Yavuz

Objectives: To investigate the factors which might influence the sonographic fetal weight estimation (SFWE) accuracy. Methods: This prospective study was conducted among 949 singleton term pregnant women who delivered at a tertiary center, from January 2017 to December 2017. All participants’ maternal (i.e. parity, age, body mass index and gestational weight gain during pregnancy), fetal sonographic (i.e. fetal presentation, amniotic fluid index, localization of placenta and estimated fetal weight) and neonatal (birth weight and gender) characteristics were recorded. A p<0.05 was considered significant. Results: The mean absolute percent error (APE) values of SFWE was 8.2±6.5 percent, and overall failure ratio (APE >10%) was 33%. In failure group, primiparous woman and cephalic presentation fetus were significantly more common compared to accuracy group (55.9% vs.44.8%; p=0.001 and 98% vs. 95.2%; p=0.03, respectively). In contrast, the mean neonatal birth weight (NBW) value was significantly lower in failure group compared to success group (3250±565 gr vs. 3404±410 gr; p=0.001). The correlation between SFWE and NBW was linear, however negative, and significant (p=0.001). Logistic regression analysis revealed that primiparous woman, cephalic presentation fetus and <3300 gr NBW were independent risk factors for the SFWE failure (relative risks were 1.6, 2.8 and 2.4 respectively, p<0.05). Conclusion: SFWE has a high correlation with NBW, however it’s accuracy is still unsatisfactory, and depend on many unpredictable and inconsistent factors. How to cite this:Tas EE, Kir EA, Yilmaz G, Yavuz AF. Accuracy of sonographic fetal weight estimation in full-term singleton pregnant women. Pak J Med Sci. 2019;35(1):34-38. doi: https://doi.org/10.12669/pjms.35.1.373 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


1970 ◽  
Vol 39 (135) ◽  
pp. 284-286
Author(s):  
Kaveeta Dawaka ◽  
G C Das

One hundred antenatal patients were studied at term pregnancy at Gauhati Medical College, Guwahati, andfetal birth weight estimation was done in utero Ultrasono-graphically. The parameters measured wereAbdominal Circumference (AC), Biparietal diameter (BPD) and Femur Length (FL), Fetal weightprediction was done with Shepards formula using AC and BPD as well as Hadlocks formula using FL andAC. The scan delivery interval was maintained at 72 hours or less. Results of both formulae were comparedwith the actual fetal birthweight taken within 15 minutes of delivery. With Shepards formula, the predictedfetal weight was within 100 gm of the actual fetal weight in 71% cases, within 150gm in 86% cases, within200 gms in 93% cases and within 250 gms in 98%. With Hadlocks formula, the predicted birthweight waswithin 100 gms of the actual fetal weight in 72% cases, within 150 gms in 83%, within 200 gms in 92%cases and within 300 gms in 98%. The mean percent error calculated as Error % = Predicted weight - actualweight divided by actual weight x 100 was 2.9% with Shepards formula and 3% with Hadlocks. These datathus support a significant correlation between ultrasonographic estimation and actual fetal birth weight.Key Words: Fetal birth weight, AC, BPD, FL


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