Accuracy of antenatal ultrasound in predicting large-for-gestational-age babies: population-based cohort study.

BACKGROUND: Pregnancies with large-for-gestational-age fetuses are at increased risk of adverse maternal and neonatal outcomes. There is uncertainty about how to manage birth in such pregnancies. Current guidelines recommend a discussion with women of the pros and cons of options, including expectant management, induction of labor, and cesarean delivery. For women to make an informed decision about birth, antenatal detection of large for gestational age is essential. OBJECTIVE: To investigate the ability of antenatal ultrasound scans to predict large for gestational age at birth. STUDY DESIGN: In this retrospective cohort study, we analyzed data from a routinely collected database from the West Midlands, United Kingdom. We included pregnancies that had an antenatal ultrasound-estimated fetal weight between 35+0 and 38+0 weeks gestation for any indication and a subgroup where the reason for the scan was that the fetus was suspected to be big. Large for gestational age was defined as >90th customized GROW percentile for estimated fetal weight as well as neonatal weight. In addition, we tested the performance of an uncustomized standard, with Hadlock fetal weight >90th percentile and neonatal weight >4 kg. We calculated diagnostic characteristics for the whole population and groups with different maternal body mass indexes. RESULTS: The study cohort consisted of 26,527 pregnancies, which, on average, had a scan at 36+4 weeks gestation and delivered 20 days later at a median of 39+3 weeks (interquartile range 15). In total, 2241 (8.4%) of neonates were large for gestational age by customized percentiles, of which 1459 (65.1%) had a scan estimated fetal weight >90th percentile, with a false positive rate of 8.6% and a positive predictive value of 41.0%. In the subgroup of 912 (3.4%) pregnancies scanned for a suspected large fetus, 293 (32.1%) babies were large for gestational age at birth, giving a positive predictive value of 50.3%, with a sensitivity of 77.1% and false positive rate of 36.0%. When comparing subgroups from low (<18.5 kg/m2) to high body mass index (>30 kg/m2), sensitivity increased from 55.6% to 67.8%, false positive rate from 5.2% to 11.5%, and positive predictive value from 32.1% to 42.3%. A total of 2585 (9.7%) babies were macrosomic (birthweight >4 kg), and of these, 1058 (40.9%) were large for gestational age (>90th percentile) antenatally by Hadlock's growth standard, with a false positive rate of 4.9% and a positive predictive value 41.0%. Analysis within subgroups showed better performance by customized than uncustomized standards for low body mass index (<18.5; diagnostic odds ratio, 23.0 vs 6.4) and high body mass index (>30; diagnostic odds ratio, 16.2 vs 8.8). CONCLUSION: Late third-trimester ultrasound estimation of fetal weight for any indication has a good ability to identify and predict large for gestational age at birth and improves with the use of a customized standard. The detection rate is better when an ultrasound is performed for a suspected large fetus but at the risk of a higher false positive diagnosis. Our results provide information for women and clinicians to aid antenatal decision-making about the birth of a fetus suspected of being large for gestational age.

Evaluating the accuracy of sonographic fetal weight estimations using the Hadlock IV formula in a Chinese population.

Background: Despite being the most generalized formula in China, the Hadlock IV formula has never been examined to determine if it is suitable for Chinese newborns, nor have the factors that might affect its performance been investigated. However, previous studies have reported varying results about other formulas in other nationalities. This study sought to evaluate the performance of the Hadlock IV formula in estimating fetal weight (FW) in pregnant Chinese women and use ultrasound to identify the factors affecting the accuracy of estimations of newborn weight; through these means, we aimed to create a reference for predicting neonatal weight for obstetricians. Methods: A retrospective observational study comprising data from 976 cases of live-birth singleton pregnancies at the Shanghai General Hospital was conducted. The participants' clinical data were examined and subjected to a logistic regression analysis to identify the multitude of possible factors affecting the estimation of FW. The proportions and correlations between the accurate and inaccurate estimation groups were compared to determine the different prognosis of these 2 groups. The correlations between the accuracy of the sonographic-based fetal weight estimation (SFWE) and newborns with different weight ranges were also analyzed. Results: The overall accuracy rate of the SFWE predicted by the Hadlock IV formula was 79.61%, while that of the inaccurate estimation group was only 20.39%. The incidence of spontaneous vaginal delivery (VD) was lower in the inaccurate estimation group than in the accurate estimation group (40.7% vs. 48.13%; P=0.041). In the inaccurate estimation group, 11.56% (23/199) of the participants underwent a secondary cesarean section (sCS), compared to only 6.44% (50/777) in the accurate estimation group. The low birth weight (LBW) rates and macrosomia rates were lower in the accurate estimation group than in the inaccurate estimation group, with odds ratios (ORs) of 0.483 and 0.459, respectively (P<0.05). The results indicated that the SFWE was more accurate for newborns weighing 2,500-4,000 g than those weight out of this range. In relation to macrosomia, the SFWE was likely to be underestimated, but it was usually overestimated in the LBW group. Conclusions: The overall performance of the Hadlock IV formula in predicting the birth weight of Chinese newborns remains suboptimal. Extra caution should be exercised in cases of suspected large-for-gestational age (LGA) infants, small-for-gestational age (SGA) infants, infants with macrosomia, or LBW fetuses in the Chinese population.

Fetal growth restriction and small for gestational age as predictors of neonatal morbidity: which growth nomogram to use?

BACKGROUND: Fetal growth nomograms were developed to screen for fetal growth restriction and guide clinical care to improve perinatal outcomes; however, existing literature remains inconclusive regarding which nomogram is the gold standard. OBJECTIVE: This study aimed to compare the ability of 4 commonly used nomograms (Hadlock, International Fetal and Newborn Growth Consortium for the 21st Century, Eunice Kennedy Shriver National Institute of Child Health and Human Development-unified standard, and World Health Organization fetal growth charts) and 1 institution-specific reference to predict small for gestational age and poor neonatal outcomes. STUDY DESIGN: This was a retrospective cohort study of all nonanomalous singleton pregnancies undergoing ultrasound at ≥20 weeks of gestation between 2013 and 2020 and delivering at a single academic center. Using random selection methods, the study sample was restricted to 1 pregnancy per patient and 1 ultrasound per pregnancy completed at ≥22 weeks of gestation. Fetal biometry data were used to calculate estimated fetal weight and percentiles according to the aforementioned 5 nomograms. Maternal and neonatal data were extracted from electronic medical records. Logistic regression was used to estimate the association between estimated fetal weight of <10th and <3rd percentiles compared with estimated fetal weight of 10th to 90th percentile as the reference group for small for gestational age and the neonatal composite outcomes (perinatal mortality, hypoxic-ischemic encephalopathy or seizures, respiratory morbidity, intraventricular hemorrhage, necrotizing enterocolitis, hyperbilirubinemia or hypoglycemia requiring neonatal intensive care unit admission, and retinopathy of prematurity). Receiver operating characteristic curve contrast estimation (primary analysis) and test characteristics were calculated for all nomograms and the prediction of small for gestational age and the neonatal composite outcomes. We restricted the sample to ultrasounds performed within 28 days of delivery; moreover, similar analyses were completed to assess the prediction of small for gestational age and neonatal composite outcomes. RESULTS: Among 10,045 participants, the proportion of fetuses classified as <10th percentile varied across nomograms from 4.9% to 9.7%. Fetuses with an estimated fetal weight of <10th percentile had an increased risk of small for gestational age (odds ratio, 9.9 [95% confidence interval, 8.5-11.5] to 12.8 [95% confidence interval, 10.9-15.0]). In addition, the estimated fetal weight of <10th and <3rd percentile was associated with increased risk of the neonatal composite outcome (odds ratio, 2.4 [95% confidence interval, 2.0-2.8] to 3.5 [95% confidence interval, 2.9-4.3] and 5.7 [95% confidence interval, 4.5-7.2] to 8.8 [95% confidence interval, 6.6-11.8], respectively). The prediction of small for gestational age with an estimated fetal weight of <10th percentile had a positive likelihood ratio of 6.3 to 8.5 and an area under the curve of 0.62 to 0.67. Similarly, the prediction of the neonatal composite outcome with an estimated fetal weight of <10th percentile had a positive likelihood ratio of 2.1 to 3.1 and an area under the curve of 0.55 to 0.57. When analyses were restricted to ultrasound within 4 weeks of delivery, among fetuses with an estimated fetal weight of <10th percentile, the risk of small for gestational age increased across all nomograms (odds ratio, 16.7 [95% confidence interval, 12.6-22.3] to 25.1 [95% confidence interval, 17.0-37.0]), and prediction improved (positive likelihood ratio, 8.3-15.0; area under the curve, 0.69-0.75). Similarly, the risk of neonatal composite outcome increased (odds ratio, 3.2 [95% confidence interval, 2.4-4.2] to 5.2 [95% confidence interval, 3.8-7.2]), and prediction marginally improved (positive likelihood ratio, 2.4-4.1; area under the curve, 0.60-0.62). Importantly, the risk of both being small for gestational age and having the neonatal composite outcome further increased (odds ratio, 21.4 [95% confidence interval, 13.6-33.6] to 28.7 (95% confidence interval, 18.6-44.3]), and the prediction of concurrent small for gestational age and neonatal composite outcome greatly improved (positive likelihood ratio, 6.0-10.0; area under the curve, 0.80-0.83). CONCLUSION: In this large cohort, Hadlock, recent fetal growth nomograms, and a local population-derived fetal growth reference performed comparably in the prediction of small for gestational age and neonatal composite outcomes.

The accuracy of international and national fetal growth charts in detecting small-for-gestational-age infants using the Lambda-Mu-Sigma method.

Objective: To construct a national fetal growth chart using retrospective data and compared its diagnostic accuracy in predicting SGA at birth with existing international growth charts. Method: This is a retrospective study where datasets from May 2011 to Apr 2020 were extracted to construct the fetal growth chart using the Lambda-Mu-Sigma method. SGA is defined as birth weight <10th centile. The local growth chart's diagnostic accuracy in detecting SGA at birth was evaluated using datasets from May 2020 to Apr 2021 and was compared with the WHO, Hadlock, and INTERGROWTH-21st charts. Balanced accuracy, sensitivity, and specificity were reported. Results: A total of 68,897 scans were collected and five biometric growth charts were constructed. Our national growth chart achieved an accuracy of 69% and a sensitivity of 42% in identifying SGA at birth. The WHO chart showed similar diagnostic performance as our national growth chart, followed by the Hadlock (67% accuracy and 38% sensitivity) and INTERGROWTH-21st (57% accuracy and 19% sensitivity). The specificities for all charts were 95-96%. All growth charts showed higher accuracy in the third trimester, with an improvement of 8-16%, as compared to that in the second trimester. Conclusion: Using the Hadlock and INTERGROWTH-21st chart in the Malaysian population may results in misdiagnose of SGA. Our population local chart has slightly higher accuracy in predicting preterm SGA in the second trimester which can enable earlier intervention for babies who are detected as SGA. All growth charts' diagnostic accuracies were poor in the second trimester, suggesting the need of improvising alternative techniques for early detection of SGA to improve fetus outcomes.

Accuracy of the sonographic determination of estimated fetal weight in anhydramnios.

OBJECTIVE: To determine whether the presence of anhydramnios significantly influences the sonographic estimated fetal weight (EFW) compared to a matched cohort with normal amniotic fluid volume. METHODS: The study sample of this retrospective case-control study consisted of 114 pregnant women who presented to a Tertiary Perinatal Clinic between 2015 and 2020. 57 of them presented with an anhydramnios and a matched cohort of 57 women with normal amniotic fluid volume. At time of admission, gestational age varied between 22 + 4 and 42 + 6 weeks of pregnancy. All women underwent detailed ultrasound assessment for EFW and amniotic fluid index. To determine EFW Hadlock's estimation formula I was used which is based on measurements of biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL). The EFW was compared with the weight at delivery. The maximum time interval between measurement and delivery was 5 days. RESULTS: There was neither a significant difference between the case and control group with regard to gestational age at ultrasound in days (median 249 days and 246 days, p = 0.97), nor to gestational age at birth (median 249 days and 247 days, p = 0.98). Concerning the newborns parameters, the body length at birth was not significantly different between the case and control group in centimeters (cm) (median 47 cm and 47 cm, p = 0.79). EFW in gram (g) was lower than birth weight in both groups and did not differ significantly between case and control group (estimated weight median 2247 g and 2421 g, p = 0.46; birth weight median 2440 g and 2475 g, p = 0.47). The difference between EFW and birth weight in percent (%) did not differ between the case and control group (median - 3.9% and - 5.6%, p = 0.70). The maternal parameters showed that the patients in the case group were younger (median 31 years and 38 years p = 0.20) and had a significantly higher body mass index (BMI) (median 27.3 kg/m2 vs 22.0 kg/m2, < 0.001) compared to the control group. CONCLUSION: Our study shows for the first time that EFW in women with anhydramnios can be determined sonographically just as accurately as in a matched cohort with normal amniotic fluid volume. A reliable estimation of fetal weight is crucial for optimal assessment of the newborns prognosis and counseling of the parents especially when advising women in the early weeks of pregnancy at the limit of viability.

Ultrasonographic fetal thigh measurement in the estimation of fetal weight based on Isobe's formula in women with an engaged fetal head in the pelvis: a comparative study.

PURPOSE: Because of the inaccuracy of the biparietal diameter in cases with an engaged fetal head in the pelvis, measuring the estimated fetal weigh (EFW) using Hadlock's formula could be compromised in these cases. The aim of this prospective study is to determine the accuracy of using only two thigh parameters, the femur length (FL) and the cross-sectional area of the thigh (CSAT) (Isobe's formula), in detecting the fetal weight of both engaged pelvis fetuses and non-engaged head fetuses and to compare this method with Hadlock's formula in both groups using the actual birth weight as a gold standard. METHODS: The study included 51 cases with an engaged fetal head and 51 cases with a non-engaged fetal head that came in active labour. 2D ultrasonography examination was performed to determine the EFW using both Hadlock's formula and Isobe's formula. The EFW was then compared with the actual birth weight after delivery. RESULTS: There was a strong positive correlation between Isobe's formula and the actual birth weight in the engaged fetal head group (r = 0.993, p < 0.01), but there was a strong positive correlation between Hadlock's formula and the actual birth weight in the non-engaged fetal head group (r = 0.994, p < 0.01). CONCLUSION: We concluded that Isobe's formula is convenient in predicting the fetal weight, especially when head measurements are difficult to assess (in the engaged fetal head group). It can be used with 2D ultrasonography as an alternative to Hadlock's formula in cases with an engaged fetal head in the pelvis.

Accuracy of ultrasound estimation of fetal weight at term: A comparison of shepard and hadlock methods.

Background: Ultrasound measurement provides a noninvasive means of obtaining information about fetal weight and may help in necessary preparations at and after delivery. Although some ultrasound methods include only one or two fetal indices, others, to improve accuracy, incorporate either three or all the four fetal indices. The aim of this report is to assess the accuracy of two different methods for fetal weight estimation. Materials and Methods: This was a prospective study of 170 consecutive pregnant women at term. Ultrasound was used to estimate fetal weight by the Shepard and Hadlock methods, and the actual birth weight (ABW) was determined at birth. The ultrasound-estimated fetal weights (EFWs) and ABW were analyzed. Results: The women were aged 21-42 years (mean 31.3 ± 7 years). The EFW using the Shepard method was 1.9 kg-5.0 kg (mean 3.6 ± 0.5 kg) and 1.8 kg-4.4 kg (mean 3.3 ± 0.4 kg) for Hadlock method, and ABW was 2.0 kg-4.5 kg (mean 3.4 ± 0.5 kg). The mean EFW using the Shepard method was significantly higher than that of ABW (P < 0.001). The Shepard method significantly overestimated macrosomia compared to that by the ABW. There was no significant difference in microsomia rate between the two methods and ABW. Conclusion: The Hadlock method was more accurate at estimating fetal weight compared to the Shepard method and is recommended for the ultrasound estimation of fetal weight in our setting and similar settings.

Résumé Contexte: La mesure par ultrasons fournit un moyen non invasif d'obtenir des informations sur le poids du fœtus et peut aider à préparations nécessaires à et après l'accouchement. Bien que certaines méthodes d'échographie n'incluent qu'un ou deux indices fœtaux, d'autres, pour améliorer précision, incorporent trois ou tous les quatre indices fœtaux. Le but de ce rapport est d'évaluer l'exactitude de deux méthodes différentes pour estimation du poids fœtal. Matériels et méthodes: Il s'agissait d'une étude prospective de 170 femmes enceintes consécutives à terme. Ultrason a été utilisé pour estimer le poids fœtal par les méthodes Shepard et Hadlock, et le poids réel à la naissance (ABW) a été déterminé à la naissance. le les poids fœtaux estimés par échographie (EFW) et ABW ont été analysés. Résultats: Les femmes étaient âgées de 21 à 42 ans (moyenne 31,3 ± 7 ans). le EFW utilisant la méthode Shepard était de 1,9 kg à 5,0 kg (moyenne 3,6 ± 0,5 kg) et de 1,8 kg à 4,4 kg (moyenne 3,3 ± 0,4 kg) pour la méthode Hadlock, et ABW était de 2,0 kg à 4,5 kg (moyenne 3,4 ± 0,5 kg). L'EFW moyen en utilisant la méthode Shepard était significativement plus élevé que celui d'ABW (P < 0,001). le La méthode Shepard surestimait significativement la macrosomie par rapport à celle de l'ABW. Il n'y avait pas de différence significative dans la microsomie taux entre les deux méthodes et ABW. Conclusion: La méthode Hadlock était plus précise pour estimer le poids fœtal par rapport à la La méthode de Shepard est recommandée pour l'estimation échographique du poids fœtal dans notre contexte et dans des contextes similaires. Mots-clés: Précision, poids de naissance, poids fœtal, Hadlock, Shepard, échographie.

Application of new fetal growth standards in a multiethnic population.

OBJECTIVES: Ultrasound assessment of fetal growth is essential to reduce adverse pregnancy outcomes. Intergrowth-21st developed international standards. Currently, we use in France chart based on Hadlock's formula. This study aims to evaluate, the impact of switching from national curves to IG-21 curves or a combination of IG-21 with Hadlock. METHODS: The study population consisted of 3 697 singleton pregnancies with fetal biometry measured between 22 and 38 weeks of gestation. Z-scores were calculated for each biometry according to CFEF and IG-21. The estimated fetal weight and its Z-score were calculated using the Hadlock formula and IG-21 formula. RESULTS: We observed 21% of head circumference, 9% of abdominal circumference and 7% of femoral length below the 10th centile with Intergrowth-21. Concerning estimated fetal weight, IG-21 classified 13.8% fetuses as SGA, IG-21/Hadlock 10.8% and CFEF 16.1%. Between 36 and 38 weeks of gestation, IG-21 classified more fetuses as SGA than IG-21/Hadlock and CFEF, respectively 18%, 14.1% and 13.3%. CONCLUSION: The use of IG-21 or IG-21/Hadlock in the general population would lower the number of fetuses classified as SGA except for fetuses between 36 and 38 weeks. During this period, many decisions of induced early delivery or specific management are established to prevent adverse perinatal outcome. Those results must be supplemented by a comparison to newborns' weight.

Comparing fetal biometric growth velocity versus estimated fetal weight for prediction of neonatal small for gestational age.

OBJECTIVE: Growth velocities derived from fetal biometrics have been proposed to improve prediction of small for gestational age (SGA) neonates. We sought to determine if ultrasound growth velocities for abdominal circumference (AC) and estimated fetal weight (EFW) improve the prediction of SGA infants when compared to using EFW alone. STUDY DESIGN: This is a secondary analysis from a prospective study of women referred for growth ultrasounds during the third trimester. Growth velocities for AC and EFW were derived from the difference in Z-scores between measurements at the anatomy survey (18-22 weeks gestation) and later growth ultrasound (26-36 weeks gestation). Change in AC and EFW growth velocities <10th percentile were compared with prenatally suspected SGA from Hadlock EFW <10th percentile for prediction of SGA neonates. The primary outcome was defined as the sensitivity and specificity of the growth velocities and Hadlock EFW in predicting SGA neonates. Logistic regression modeling was used to determine if the growth velocities improved prediction of neonatal SGA. Area under the ROC curves (AUC) were determined and compared. RESULTS: Of 612 singleton pregnancies meeting inclusion criteria, 68 (11.1%) resulted in SGA neonates. Hadlock EFW <10th percentile had higher sensitivity and specificity when compared to AC growth velocity and EFW growth velocity. Only AC growth velocity and Hadlock EFW had significant odds ratios for association with neonatal SGA. The AUC were 0.54, 0.53, and 0.61 using AC growth velocity, EFW growth velocity, and Hadlock EFW, respectively. The AUC did not significantly improve when the growth velocities were combined with Hadlock EFW (0.63). Adjustment of Z-scores for gestational age at anatomy scan or third trimester growth scan did not significantly change these results (AUC = 0.69). CONCLUSION: EFW determined by Hadlock formula has the highest predictive value in detecting SGA neonates when compared to both AC and EFW growth velocities.

The value of fetal growth biometry velocities to predict large for gestational age (LGA) infants.

OBJECTIVE: The use of growth velocities derived from fetal biometrics have been suggested to improve prediction of large for gestational age (LGA). Our objective was to determine if ultrasonographic growth velocities (GV) for abdominal circumference (AC) and estimated fetal weight (EFW) improve the prediction of LGA infants when compared to Hadlock EFW. METHODS: This was a secondary analysis of data from a prospective study of women referred for growth ultrasounds during the 3rd trimester. Growth velocities (GV) for AC (AC - GV) and EFW (EFW - GV) were derived from the difference in Z-scores between measurements at the time of anatomy survey (18-24 week) and third trimester ultrasound (26-36 weeks). Change in AC - GV and EFW - GV >90th %ile alone or in combination with Hadlock EFW >90th%ile were compared for prediction of a LGA neonate. The primary outcome was the sensitivity and specificity of the (1) Hadlock EFW >90%ile, (2) AC - GV, (3) EFW - GV, (4) Hadlock EFW + AC - GV, and (5) Hadlock EFW + EFW - GV for the prediction of neonatal LGA. Test characteristics and area under the ROC curve (AUC) were determined. The association between the ultrasound predicted growth and adverse neonatal outcome was assessed using logistic regression. RESULTS: Of 630 women meeting inclusion criteria, 85 (13.5%) had LGA neonates. Hadlock EFW showed a better NPV (98.0%) and sensitivity (71.1%) when compared to AC - GV (NPV 87.5%, sensitivity 17.7%) and EFW - GV (NPV 88.0%, sensitivity 22.6%). Combining Hadlock EFW and AC-GV or EFW - GV did little to improve the test characteristics for the prediction of LGA (AUC 0.65 and 0.64, respectively). All five measurements were unable to predict a composite of adverse neonatal outcome or need for maternal cesarean delivery. Adjustment of the growth velocities for gestational age at anatomy scan or 3rd trimester growth scan did not change these results. CONCLUSION: AC and EFW growth velocities do not appear to improve the prediction of LGA infants when compared to using the third trimester Hadlock EFW.

Accuracy of ultrasound in estimating fetal weight in New Zealand.

INTRODUCTION: Ultrasound estimation of fetal weight is an important factor guiding antenatal management. We aimed to review the accuracy of ultrasound in predicting fetal weight and birthweight category and identify influencing factors. METHODS: We performed a retrospective study of term pregnant women who underwent ultrasound within 7 days of delivery at National Women's Health between January 2019 and January 2020. Stillbirths, major fetal anomalies and multiple pregnancies were excluded. Estimated fetal weight (EFW) was calculated using Hadlock formula and compared with birthweights. We evaluated change in weight categories due to these errors. RESULTS: Of 560 fetuses included, three quarters (n = 425, 76%) of EFWs were within 10% of birthweight. 135 fetuses had EFWs either less than 90% (n = 19) or greater than 110% (n = 116). Fetuses with EFW < 90% had longer times between scanning and delivery, lower EFW and higher maternal BMI. Fetuses with EFW > 110% were associated with higher EFW, later gestational age and older maternal age. US incorrectly estimated 71 (12.7%) fetal birthweight categories. Underestimated weight category (8.9%) was associated with higher maternal BMI. DISCUSSION: Inaccurate EFWs were more common at the extremes of fetal weight. A significant association was underestimation birthweight in mothers with increased BMI, who are at increased risk for perinatal and surgical complications. CONCLUSION: Our accuracy of 76% correctly predicted EFWs compares favourably with previous studies. Clinicians and sonographers should be aware of the increased risk for inaccurate categorisation of fetuses at the extremes of EFW and in mothers with increased BMI.

Role of thigh circumference in predicting the fetal weight: Comparison with other ultrasound methods-A prospective observational study.

AIM: We aimed to evaluate the addition of fetal thigh circumference (TC) to other ultrasound parameters to predict fetal weight compared to two standard formulae (Hadlock's and Vintzileos methods). METHODS: We conducted this prospective study on pregnant women between November 2018 and September 2019. The actual fetal weight was estimated within 48 h of delivery; then, it was compared to the estimated fetal weight by ultrasound. We used the Statistical Package for the Social Sciences (SPSS) software version 20.0 to perform the statistical analysis. RESULTS: A total of 123 pregnant women, with a mean age of 26.68 (5.24) years and a mean gestational age of 38.78 (0.85) weeks, were included in our study. We detected a significant positive correlation between different ultrasound parameters and actual weight (all p ≤ 0.001). The highest correlation was observed between TC and actual fetal weight (r = 0.685). Regarding both formulae, the correlation coefficient was higher in the Vintzileos formula than the Handlock formula (0.976 vs. 0.823). Our linear regression analysis showed that fetal TC could be an indicator for estimating fetal weight (p < 0.001). There was a statistically significant difference between the actual weight and the weight estimated by the Hadlock formula (p < 0.001). We detected no statistically significant difference between the estimated TC by ultrasound and the actual TC (p = 0.0602). CONCLUSION: Fetal TC can help accurately measure fetal birth weight when incorporated with other fetal parameters. The inclusion of fetal TC assessment in routine ultrasound examination is suggested to improve the birth estimates.

Diagnostic accuracy of modified Hadlock formula for fetal macrosomia in women with gestational diabetes and pregnancy weight gain above recommended.

OBJECTIVES: Women with gestational diabetes (GDM) and weight gain during pregnancy above recommended more often give birth to macrosomic children. The goal of this study was to evaluate the diagnostic accuracy of the modified formula for ultrasound assessment of fetal weight created in a pilot study using a similar specimen in comparison to the Hadlock-2 formula. METHODS: This is a prospective, cohort, applicative, observational, quantitative, and analytical study, which included 213 pregnant women with a singleton pregnancy, GDM, and pregnancy weight gain above recommended. Participants were consecutively followed in the time period between July 1st, 2016, and August 31st, 2020. Ultrasound estimations were made within three days before the delivery. Fetal weights estimated using both formulas were compared to the newborns' weights. RESULTS: A total of 133 fetal weight estimations were made. In comparison to the newborns' weight modified formula had significantly smaller deviation in weight estimation compared to the Hadlock-2 formula, higher frequency of deviation within 5% of newborns weights (78.2% [95% CI=0.74-0.83] vs. 60.2%), smaller frequency of deviations from 5 to 10% (19.5 vs. 33.8%) and above 10%, which was even more significant among macrosomic children. There were 36/50 (72%) correctly diagnosed cases of macrosomia by modified and 33/50 (66%) by Hadlock-2 formula. Area under the curve (AUC) for the modified formula was 0.854 (95% CI=0.776-0.932), and for the Hadlock-2 formula 0.824 (95% CI=0.740-0.908). The positive predictive value of the modified formula was 81.81%, the negative 97.91%. CONCLUSIONS: In cases of greater fetal weights, the modified formula showed greater precision.

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

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.

The Ability of Ultrasound Sonography (USG) to Detect Intrauterine Growth Restriction (IUGR) in the Third Trimester of Pregnancy With the Gold Standard of IUGR (Parameters by USG Hadlock) as a Diagnostic Criterion.

Objective To investigate the diagnostic accuracy of the placental thickness measured by ultrasound sonography test (USG) in detecting intrauterine growth restriction (IUGR) babies in the third trimester of pregnancy, keeping IUGR (by parameters using Hadlock) as the gold standard. Methods and materials This cross-sectional study was conducted at the radiology department of KRL Hospital from August 5, 2020, to October 25, 2021. Informed written consent was also obtained from each patient, and the hospital's ethical committee approved the study. Three hundred and sixty-two (N=362) pregnant women patients knowing of their last menstrual period, age group 20-35 years, BMI usual, and 24 weeks gestation were included. The patient's complete history was taken by clinical examination and then ultrasound was carried out to measure the placental thickness. At 24, 32, and 36 weeks, the thickness of the placenta was assessed. The Hadlock method was used to compute the predicted fetal weight by measuring biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL) on the GC Logiq P/6 three-dimensional machine (GE, Tampa, FL). SPSS v 23 (IBM Corp., Armonk, NY) was used to calculate the mean and standard deviation from the collected data. Results A total of 362 patients who presented in the radiology department for antenatal ultrasound in the third trimester were recruited in our study. The mean age was 27.26 ± 4.21 years (20-35 years). In our study, the mean placenta thickness at 24 gestation weeks was 24.55 ± 0.79 mm, at 32 gestation weeks was 31.84 ± 1.34 mm, and at 36 gestation weeks was 35.54 ± 2.78. Thus, ultrasound's sensitivity, specificity, positive predictive value, and negative predictive value to determine IUGR by placental thickness was 86.30%, 86.70%, 75%, and 92%, respectively. The diagnostic accuracy of ultrasound incorrectly estimating low placental thickness was 86.40%. Conclusion Between 24 and 36 weeks of pregnancy, placental thickness rises almost linearly. As a result, measuring placental thickness and other factors is critical for estimating fetal age, particularly in the late second and early third trimesters, when the exact duration of pregnancy is uncertain. Placentas that were less than 29 mm thick at 32 weeks and 31 mm thick at 36 weeks were related to higher morbidity, lower Apgar scores, and more nursery admissions.

Comparison of clinical and ultrasonographic estimation of foetal weight at term and their correlation with birth weight.

The study compares the accuracy of clinical and ultrasonographic estimation of foetal weight at term in predicting birth weight. It was a prospective comparative study conducted in a tertiary hospital in Abuja, Nigeria between May and August 2018. Three hundred pregnant women planned for delivery were recruited. In-utero clinical estimation of foetal weight was carried out using Dare's clinical method and sonographic estimation using Hadlock 3 formula. The newborn babies were weighed within 30 minutes of delivery. The difference in the accuracy of the clinical method (75.3%) and the ultrasonographic method (82.3%) was statistically significant (p-value=0.023). The accuracy of the clinical method among parturients whose BMI were <30kg/m2 and ≥30.0kg/m2 were 83.5% and 68.5% respectively while that of the ultrasonographic method were 85.2% and 80% respectively. We conclude that ultrasonographic estimation of foetal weight is more accurate than the clinical method. However clinical method may be used when an ultrasound scan is not accessible.

Fetal ultrasound parameters: Reference values for a local perspective.

BACKGROUND: Fetal biometry, with the help of ultrasonography (USG) provides the most reliable and important information about fetal growth and well-being. Frequently used parameters for fetal measurements by this method are the biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL). These fetal dimensions depend upon the racial demographic characteristics, nutrition, genetics and many more environmental factors of a particular population. AIMS: The purpose of the present investigation was to define and analyze these fetal biometric parameters in our local population and to compare them with the given norms. METHODS: This cross-sectional study with convenience sampling was conducted on a total of 425 fetuses with a period of gestation between 18 to 38 weeks. Descriptive statistics was used to calculate the mean with standard deviation and 95% confidence interval (CI) for each fetal parameter in each gestational week. RESULTS: Mean of BPD and FL in our population are similar to the mean values given by Hadlock throughout the pregnancy, except near the end of the third trimester where our population shows a slightly lower range of mean values. HC and AC fall below the lower range of Hadlock as early as 24 weeks of pregnancy. CONCLUSIONS: Fetal biometric parameters in the studied population are at the lower range of established nomograms by Hadlock on white fetuses, more so with the progression of pregnancy.

Use of birth weight- vs. ultrasound-derived fetal weight classification methods: implications for detection of abnormal umbilical artery Doppler.

Objectives To compare a birth weight-derived (Brenner) and multiple ultrasound-derived [Hadlock, National Institute of Child Health and Human Development (NICHD), International Fetal and Newborn Growth Consortium (INTERGROWTH)] classification systems' frequency of assigning an antenatal estimated fetal weight (EFW) <10% and subsequent detection rate for abnormal umbilical artery Doppler (UAD). Methods We analyzed 569 consecutive non-anomalous singleton gestations identified by ultrasound with either an abdominal circumference (AC) <3% or EFW <10% at a tertiary medical center between 1/2012 and 12/2016. The biometric measurements were exported for all serial ultrasounds and the sensitivity, specificity, positive and negative predictive values, and area under the curve (AUC) were calculated for the diagnosis of any abnormal UAD, absent or reversed end-diastolic flow (AREDF), and small for gestational age (SGA) for each classification method. Results Brenner classified less patients with EFW <10% (49.7%) vs. the comparison methods (range: 84.2-85.0%; P < 0.001). The sensitivity was highest using Hadlock for detection of any abnormal UAD [96.6%; confidence interval (CI) 92.8-98.8%], AREDF (100%; CI 95.1-100%), and SGA (89.0%; CI 85.4-91.6%). However, there was minimal variation between the Hadlock, NICHD, and INTERGROWTH methods for detection of the studied outcomes. The AUCs for any abnormal UAD, AREDF, and SGA were highest for the Brenner method, but there were a substantial number of false-negative results with lower overall detection rates. Conclusions Use of a birth weight-derived method to assign a fetal weight <10% as the threshold to initiate UAD surveillance has a lower detection rate for abnormal UAD when compared to ultrasound-derived methods. Despite substantial methodological differences in the creation of the Hadlock, NICHD, and INTERGROWTH methods, there were no differences in the detection rates of abnormal UAD.

Comparison of eleven commonly used formulae for sonographic estimation of fetal weight in prediction of actual birth weight.

OBJECTIVES: The aim of the study is to compare the accuracy of 11 formulas in predicting fetal weight. MATERIAL AND METHODS: The study includes 1072 pregnant women of gestational age from 28 to 42 weeks, who gave birth between January and June 2017. Pregnant women were divided into five groups; group 1, where actual birth weight (ABW) was less than 2500 g, group 2, where ABW was between 2500-4000 g, group 3, where ABW was above 4000 g. Group 4 - newborns with birth weight under 10 percentile and group 5 - newborns with birth weight above 90 percentile. The accuracy of the estimated fetal weight (EFW) was assessed by calculating absolute percentage error (APE) and 'limits-of-agreement'. R Spearman correlation was utilized between EFW and ABW. RESULTS: The most accurate formula for group 1 is Hadlock3 (MAPE = 7.04%), the narrowest limits of agreement has Combs - [mean (SD): 99.41 g (269.57 g)]. For group 2, the lowest MAPE (5.43%) has Ott, the narrowest limits of agreement belongs to Combs - [mean (SD): -101.36 g (275.88 g)] . For group 3 is Hadlock3 (MAPE = 5.79%), the narrowest limits of agreement has Hadlock5 [mean (SD): -637.32 g (209.59 g)]. For group 4 is Combs (MAPE = 7.72%), the narrowest limits of agreement has Combs [mean (SD): 195.77 g (264.97 g)]. For gr oup 5 is Warsof2 (MAPE = 7.06%), the narrowest limits of agreement has Campbell [mean (SD): 227.81 g (299.26 g)]. CONCLUSIONS: Median of absolute percentage error is the most useful parameter to predict birth weight. Each group of fetuses needs different formula to predict the most accurate weight.

Does the Porter formula hold its promise? A weight estimation formula for macrosomic fetuses put to the test.

PURPOSE: Estimating fetal weight using ultrasound measurements is an essential task in obstetrics departments. Most of the commonly used weight estimation formulas underestimate fetal weight when the actual birthweight exceeds 4000 g. Porter et al. published a specially designed formula in an attempt to improve detection rates for such macrosomic infants. In this study, we question the usefulness of the Porter formula in clinical practice and draw attention to some critical issues concerning the derivation of specialized formulas of this type. METHODS: A retrospective cohort study was carried out, including 4654 singleton pregnancies with a birthweight ≥ 3500 g, with ultrasound examinations performed within 14 days before delivery. Fetal weight estimations derived using the Porter and Hadlock formulas were compared. RESULTS: Of the macrosomic infants, 27.08% were identified by the Hadlock formula, with a false-positive rate of 4.60%. All macrosomic fetuses were detected using the Porter formula, with a false-positive rate of 100%; 99.96% of all weight estimations using the Porter formula fell within a range of 4300 g ± 10%. The Porter formula only provides macrosomic estimates. CONCLUSIONS: The Porter formula does not succeed in distinguishing macrosomic from normal-weight fetuses. High-risk fetuses with a birthweight ≥ 4500 g in particular are not detected more precisely than with the Hadlock formula. For these reasons, we believe that the Porter formula should not be used in clinical practice. Newly derived weight estimation formulas for macrosomic fetuses must not be based solely on a macrosomic data set.