Prediction of Small for Gestational Age: Accuracy of Different Sonographic Fetal Weight Estimation Formulas

2016 ◽  
Vol 40 (3) ◽  
pp. 205-213 ◽  
Author(s):  
Rinat Gabbay-Benziv ◽  
Amir Aviram ◽  
Ron Bardin ◽  
Eran Ashwal ◽  
Nir Melamed ◽  
...  
Keyword(s):  
Systematic Error ◽  
Gestational Age ◽  
Small For Gestational Age ◽  
Random Error ◽  
Characteristic Curve ◽  
Fetal Weight ◽  
Femur Length ◽  
Error Proportion ◽  
Lower Accuracy ◽  
Sensitivity Specificity

Objective: To compare the accuracy of various sonographic estimated fetal weight (sEFW) formulas for the prediction of small for gestational age (SGA) neonates. Methods: A retrospective analysis of 6,126 fetal biometrical measurements performed within 3 days of delivery. SGA prediction was evaluated for various sEFW formulas by calculating the sensitivity, specificity, positive/negative predictive value (PPV/NPV), likelihood ratio (+LR/-LR), overall accuracy and area under the receiver operating characteristic curve (AUC). Systematic error, random error, proportion of estimates >10% of birth weights, actual and absolute weight differences were compared between SGA and non-SGA neonates. Results: Overall, 638 (10.4%) neonates were SGA. There was considerable variation among formulas in sensitivity (mean ± SD, 62 ± 14.4%; range, 32.4-91.2), PPV (72.5 ± 10.7%; 45.8-95.6) and +LR (24.2 ± 10.9; 7.2-57.3), mild variation in specificity (96.6 ± 2.7%; 87.4-99.4), NPV (94.6 ± 5.3%; 72.2-98.9) and -LR (0.4 ± 0.1; 0.1-0.7) and minimal variation in AUC (mean, 0.93; range, 0.91-0.93). The majority of formulas had a lower accuracy for the SGA neonates, with systematic error and random error ranging from -4.2 to 14.3% and from 8.4 to 12.9% for SGA, and from -8.7 to 16.1% and from 7.2 to 10.5% for non-SGA, respectively. Conclusion: sEFW formulas differ in their accuracy for SGA prediction. In our population, the most accurate formula for SGA prediction was Hadlock's formula utilizing femur length, abdominal and head circumference.

scholarly journals Estimating gestational age and its relation to the anthropometric status of newborns: a study comparing the Capurro and ultrasound methods with last menstrual period

2011 ◽  
Vol 11 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Maria de Fátima Pussick Nunes ◽  
Sandra Maria Conceição Pinheiro ◽  
Fabíola Eloy da Rocha Medrado ◽  
Ana Marlúcia Oliveira Assis
Keyword(s):  
Gestational Age ◽  
Small For Gestational Age ◽  
Predictive Value ◽  
Characteristic Curve ◽  
Rank Test ◽  
Signed Rank ◽  
Maternity Hospitals ◽  
Signed Rank Test ◽  
Term Newborns ◽  
Sensitivity Specificity

OBJECTIVE: to assess the accuracy of the Capurro somatic and ultrasound methods, taking date of last menstruation as a reference point, for evaluating gestational age and anthropometric classification of term newborns. METHODS: a prevalence study was carried out involving 309 pregnant women and their term newborns, 92 of whom were small for gestational age and 217 appropriate sized for gestational age, at two public maternity hospitals in the Brazilian city of Salvador. The evaluation of the differences between the median gestational age according to the two methods was carried out using the non-parametric "Wilcoxon Signed-Rank Test." The accuracy of the methods for evaluating gestational age for the small for gestational age newborns was estimated by calculating the sensitivity, specificity, positive predictive value, negative predictive value and ROC (Receiver Operating Characteristic) curve. RESULTS: compared to ultrasound, the Capurro method overestimated the gestational age in newbornsof less than 39 weeks and underestimated it in older newborns. Ultrasound underestimated gestational agein newborns with more than 37 weeks. CONCLUSION: ultrasound was found to have greater sensitivity for prediction of small for age newborns (96.6%), while the Capurro method presented greater specificity (75.5%). The highest accuracy was obtained using ultrasound in the 41st gestational week (ROC=77.0%).

scholarly journals Comparison of sonographic fetal weight estimation formulas in patients with preterm premature rupture of membranes

2020 ◽  
Author(s):  
Chelsie Warshafsky ◽  
Stefania Ronzoni ◽  
Paula Quaglietta ◽  
Eran Weiner ◽  
Arthur Zaltz ◽  
...  
Keyword(s):  
Birth Weight ◽  
Systematic Error ◽  
Random Error ◽  
Euclidean Distance ◽  
Pearson Correlation ◽  
Fetal Weight ◽  
Premature Rupture Of Membranes ◽  
Premature Rupture ◽  
Femur Length ◽  
Preterm Premature Rupture

Abstract Background: Estimation of fetal weight (EFW) by ultrasound is useful in clinical decision-making. Numerous formulas for EFW have been published but have not been validated in pregnancies complicated by preterm premature rupture of membranes (PPROM). The purpose of this study is to compare the accuracy of EFW formulas in patients with PPROM, and to further evaluate the performance of the most commonly used formula - Hadlock IV.Methods: A retrospective cohort study of women with singleton gestations and PPROM, admitted to a single tertiary center between 2003-2017 from 220/7-330/7 (n=565). All women had an EFW within 14 days of delivery by standard biometry (biparietal diameter, head circumference, abdominal circumference and femur length). The accuracy of previously published 21 estimated EFW formulas was assessed by comparing the Pearson correlation with actual birth weight, and calculating the random error, systematic error, proportion of estimates within 10% of birth weight, and Euclidean distance.Results: The mean gestational was 26.8±2.4 weeks at admission, and 28.2±2.6 weeks at delivery. Most formulas were strongly correlated with actual birth weight (r>0.9 for 19/21 formulas). Mean systematic error was -4.30% and mean random error was 14.5%. The highest performing formula, by the highest proportion of estimates and lowest Euclidean distance was Ott (1986), which uses abdominal and head circumferences, and femur length. However, there were minimal difference with all of the first 10 ranking formulas. The Pearson correlation coefficient for the Hadlock IV formula was strong at r=0.935 (p<0.001), with 319 (56.5%) of measurements falling within 10%, 408 (72.2%) within 15% and 455 (80.5%) within 20% of actual birth weight. This correlation was unaffected by gender (r=0.936 for males, r=0.932 for females, p<0.001 for both) or by amniotic fluid level (r=0.935 for mean vertical pocket <2 cm, r=0.943 for mean vertical pocket ≥2cm, p<0.001 for both). Conclusions: Most formulas accurately calculated EFW in patients with PPROM, but the Ott (1986) formula ranked highest, thus it may be the preferred formula to use in this population.

scholarly journals Comparison of sonographic fetal weight estimation formulas in patients with preterm premature rupture of membranes

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Chelsie Warshafsky ◽  
Stefania Ronzoni ◽  
Paula Quaglietta ◽  
Eran Weiner ◽  
Arthur Zaltz ◽  
...  
Keyword(s):  
Birth Weight ◽  
Systematic Error ◽  
Random Error ◽  
Euclidean Distance ◽  
Pearson Correlation ◽  
Fetal Weight ◽  
Premature Rupture Of Membranes ◽  
Premature Rupture ◽  
Femur Length ◽  
Preterm Premature Rupture

Abstract Background Estimation of fetal weight (EFW) by ultrasound is useful in clinical decision-making. Numerous formulas for EFW have been published but have not been validated in pregnancies complicated by preterm premature rupture of membranes (PPROM). The purpose of this study is to compare the accuracy of EFW formulas in patients with PPROM, and to further evaluate the performance of the most commonly used formula - Hadlock IV. Methods A retrospective cohort study of women with singleton gestations and PPROM, admitted to a single tertiary center between 2005 and 2017 from 220/7–330/7 (n = 565). All women had an EFW within 14 days of delivery by standard biometry (biparietal diameter, head circumference, abdominal circumference and femur length). The accuracy of previously published 21 estimated EFW formulas was assessed by comparing the Pearson correlation with actual birth weight, and calculating the random error, systematic error, proportion of estimates within 10% of birth weight, and Euclidean distance. Results The mean gestational was 26.8 ± 2.4 weeks at admission, and 28.2 ± 2.6 weeks at delivery. Most formulas were strongly correlated with actual birth weight (r > 0.9 for 19/21 formulas). Mean systematic error was − 4.30% and mean random error was 14.5%. The highest performing formula, by the highest proportion of estimates and lowest Euclidean distance was Ott (1986), which uses abdominal and head circumferences, and femur length. However, there were minimal difference with all of the first 10 ranking formulas. The Pearson correlation coefficient for the Hadlock IV formula was strong at r = 0.935 (p < 0.001), with 319 (56.5%) of measurements falling within 10%, 408 (72.2%) within 15% and 455 (80.5%) within 20% of actual birth weight. This correlation was unaffected by gender (r = 0.936 for males, r = 0.932 for females, p < 0.001 for both) or by amniotic fluid level (r = 0.935 for mean vertical pocket < 2 cm, r = 0.943 for mean vertical pocket ≥2 cm, p < 0.001 for both). Conclusions In women with singleton gestation and PPROM, the Ott (1986) formula for EFW was the most accurate, yet all of the top ten ranking formulas performed quite well. The commonly used Hadlock IV performed quite similarly to Ott’s formula, and is acceptable to use in this specific setting.

Sonographic prediction of small and large for gestational age in breech-presenting fetuses

2018 ◽  
Vol 46 (7) ◽  
pp. 744-749 ◽  
Author(s):  
Anat Shmueli ◽  
Amir Aviram ◽  
Ron Bardin ◽  
Kinneret Tenenbaum-Gavish ◽  
Arnon Wiznitzer ◽  
...  
Keyword(s):  
Systematic Error ◽  
Gestational Age ◽  
Random Error ◽  
Operating Characteristic ◽  
Medical Center ◽  
Large For Gestational Age ◽  
Control Group ◽  
Sensitivity Specificity ◽  
Prediction Parameters ◽  
Age Prediction

Abstract Introduction: To evaluate various sonographic estimated fetal weight (sEFW) formulas’ accuracy for small- and large-for-gestational age (SGA/LGA) prediction in breech-presenting fetuses. Materials and methods: A retrospective analysis of all ultrasound-based fetal biometrical measurements performed within 3 days of delivery in term pregnancies, in one medical center (2007–2014). Overall, 274 breech-presenting fetuses (study group) were compared to 274 vertex-presenting fetuses (control group) matched by gender, gestational age and birth weight. sEFW was calculated by six previously published formulas. Accuracy was compared utilizing systematic error and random error for every formula. Prediction precision of SGA and LGA was evaluated by calculating each formula’s sensitivity, specificity, +/− predictive value, and the area under the receiver-operating characteristic (ROC) curve (AUC). Results: Systematic error and random error varied greatly between formulas, ranging from −7.4% to 3.1%, 7.3% to 8.3% for the vertex-presenting fetuses and −8.9% to 1.9%, 7.9% to 8.6% for the breech-presenting fetuses, respectively. There was no statistical difference in small- or large-for-gestational age prediction parameters between the groups. The highest sensitivity and specificity for prediction was achieved by same formula regardless of presentation. Conclusion: In our cohort, overall accuracy was slightly superior among vertex-presenting fetuses without difference in prediction accuracy for small- and large-for-gestational age neonates.

scholarly journals 494: The effect of a sonographic estimated fetal weight on the risk of cesarean delivery in macrosomic and small for gestational age infants

2016 ◽  
Vol 214 (1) ◽  
pp. S270
Author(s):  
Nathan S. Fox ◽  
Kathy C. Matthews ◽  
John Williamson ◽  
Simi Gupta ◽  
Jennifer Lam-Rachlin ◽  
...  
Keyword(s):  
Cesarean Delivery ◽  
Gestational Age ◽  
Small For Gestational Age ◽  
Fetal Weight ◽  
Estimated Fetal Weight

scholarly journals Lipid metabolism is altered in maternal, placental, and fetal tissues of ewes with small for gestational age fetuses†

2020 ◽  
Author(s):  
Chelsie B Steinhauser ◽  
Katharine Askelson ◽  
Colleen A Lambo ◽  
Kenneth C Hobbs ◽  
Fuller W Bazer ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Bile Acids ◽  
Gestational Age ◽  
Small For Gestational Age ◽  
National Research Council ◽  
Allantoic Fluid ◽  
Fetal Weight ◽  
Placental Development ◽  
Sheep Model ◽  
Blood Concentrations

Abstract Nutrient restriction (NR) has the potential to negatively impact birthweight, an indicator of neonatal survival and lifelong health. Those fetuses are termed as small for gestational age (SGA). Interestingly, there is a spectral phenotype of fetal growth rates in response to NR associated with changes in placental development, nutrient and waste transport, and lipid metabolism. A sheep model with a maternal diet, starting at Day 35, of 100% National Research Council (NRC) nutrient requirements (n = 8) or 50% NRC (n = 28) was used to assess alterations in fetuses designated NR SGA (n = 7) or NR NonSGA (n = 7) based on fetal weight at Day 135 of pregnancy. Allantoic fluid concentrations of triglycerides were greater in NR SGA fetuses than 100% NRC and NR NonSGA fetuses at Day 70 (P &lt; 0.05). There was a negative correlation between allantoic fluid concentrations of triglycerides (R2 = 0.207) and bile acids (R2 = 0.179) on Day 70 and fetal weight at Day 135 for NR ewes (P &lt; 0.05). Bile acids were more abundant in maternal and fetal blood for NR SGA compared to 100% NRC and NR NonSGA ewes (P &lt; 0.05). Maternal blood concentrations of NEFAs increased in late pregnancy in NR NonSGA compared to NR SGA ewes (P &lt; 0.05). Protein expression of fatty acid transporter SLC27A6 localized to placentomal maternal and fetal epithelia and decreased in Day 70 NR SGA compared to 100% NRC and NR NonSGA placentomes (P &lt; 0.05). These results identify novel factors associated with an ability of placentae and fetuses in NR NonSGA ewes to adapt to, and overcome, nutritional hardship during pregnancy.

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