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.

Science of the Van Allen Probes Science Operations Centers.

The Van Allen Probes mission operations materialized through a distributed model in which operational responsibility was divided between the Mission Operations Center (MOC) and separate instrument specific SOCs. The sole MOC handled all aspects of telemetering and receiving tasks as well as certain scientifically relevant ancillary tasks. Each instrument science team developed individual instrument specific SOCs proficient in unique capabilities in support of science data acquisition, data processing, instrument performance, and tools for the instrument team scientists. In parallel activities, project scientists took on the task of providing a significant modeling tool base usable by the instrument science teams and the larger scientific community. With a mission as complex as Van Allen Probes, scientific inquiry occurred due to constant and significant collaboration between the SOCs and in concert with the project science team. Planned cross-instrument coordinated observations resulted in critical discoveries during the seven-year mission. Instrument cross-calibration activities elucidated a more seamless set of data products. Specific topics include post-launch changes and enhancements to the SOCs, discussion of coordination activities between the SOCs, SOC specific analysis software, modeling software provided by the Van Allen Probes project, and a section on lessons learned. One of the most significant lessons learned was the importance of the original decision to implement individual team SOCs providing timely and well-documented instrument data for the NASA Van Allen Probes Mission scientists and the larger magnetospheric and radiation belt scientific community.

Report of Prolonged Neonatal Hypoglycemia in Three Infants of Mothers With Variants in HNF1A.

Background/Objective: Genetic variants in hepatic nuclear factor 1α (HNF1A) cause maturity-onset diabetes of the young (MODY). We sought to examine whether HNF1A MODY variants also cause neonatal hypoglycemia. Case Report: We present 3 infants with variants in HNF1A shared with their mothers. The infants experienced neonatal hypoglycemia, 2 extending beyond 1 year and the third resolving by 28 days, and all were large for gestational age (birth weights of >99th percentile). In 2 cases, genetic testing for neonatal hypoglycemia revealed pathogenic variants in HNF1A; 1 mother was previously diagnosed with HNF1A MODY, and the other's genetic testing and ultimate MODY diagnosis were prompted by her child's hypoglycemia workup. In the third case, the infant's persistent hypoglycemia prompted genetic testing, revealing an HNF1A variant of uncertain significance, which was then identified in the mother. Discussion: Genetic variants causing HNF1A MODY have not been definitively linked to neonatal hypoglycemia or fetal overgrowth in utero. MODY caused by HNF1A is clinically similar to that caused by HNF4A, for which a causal relationship with neonatal hypoglycemia is more certain. Case reports have previously implicated variants in HNF1A in congenital hyperinsulinism; however, these cases have generally not been in families with MODY. The cases presented here suggest that HNF1A variants causing MODY may also cause neonatal hypoglycemia. Conclusion: Although confounding factors make the assessment of neonatal hypoglycemia challenging, these cases offer potential support for single genetic variants in HNF1A causing both MODY and neonatal hypoglycemia, with associated fetal overgrowth in utero.

Solitary kidney functional damage due to caesarean ureteric injury monitored for 2 years after acute management: A case report.

Caesarean section with associated ureteric injuries that damage kidney function is uncommon. Such injury in women with a solitary kidney has far-reaching effects if the diagnosis is delayed. The case report describes the successful acute management with stenting of ureteric damage after caesarean section in a woman with a solitary kidney. A 29-year-old woman presented with anuria, hypertension (174/101 mmHg) and flank pain 3 days after caesarean section. Physical examination was significant for peri-orbital oedema, left flank tenderness, pallor and delirium. A diagnosis of acute kidney injury was confirmed by elevated blood urea and creatinine levels. An ultrasound scan revealed a solitary hydronephrotic left kidney. She had successful acute management at a resource-deprived facility, with normal renal function at a 2-year follow-up. Proteinuria lasted for about three months after surgery. Recovery of solitary kidney function with acute kidney injury due to caesarean section ureteric injury may be associated with prolonged proteinuria without evidence of further functional deterioration.

Estimated fetal weight accuracy in pregnancies with preterm prelabor rupture of membranes by the Hadlock method.

OBJECTIVE: We aimed to assess the accuracy of the estimated fetal weight (EFW) to predict the birthweigth (BW) in pregnancies complicated by PPROM. STUDY DESIGN: This study was a secondary analysis of a prospective cohort of pregnancies with PPROM. We included singleton pregnancies from 23 to 36 + 6 weeks, mothers from 13 to 46 years of age, and those with an EFW within two weeks of delivery. We excluded pregnancies with complex fetal anomalies and fetal demise. The accuracy of the EFW was determined by the absolute percent difference between BW and EFW ([BW-EFW]/BW*100%). T tests and linear regression were performed for statistical analysis. RESULTS: The mean percent difference of BW vs. EFW was 8.72 ± 6.94%. The EFW was more accurate (8.24 ± 6.81 vs. 13.31 ± 6.88%, p = .027) and had more measurements with a absolute difference < 10% (70% vs. 30%; p = .034) when performed within seven days of delivery. The EFW accuracy decreased with anhydramnios (11.37 ± 7.06 vs. 7.69 ± 6.77%, p = .020), but the measurements with an absolute difference <10% was not significantly different (p = .27) with anhydramnios. CONCLUSION: In PPROM, the EFW within seven days to delivery by Hadlock accurately predicts the birthweight with a mean absolute difference of 8.2%. BRIEF RATIONALE: There are a limited number of studies evaluating the accuracy of the EFW in pregnancies with PPROM in the last four decades.

Sonographic growth curves versus neonatal birthweight growth curves for the identification of fetal growth restriction.

OBJECTIVE: Fetal growth restriction is suspected when the estimated fetal weight is <10th percentile for gestational age. Using a regional sonographic estimated fetal weight growth curve to diagnose fetal growth restriction has no known benefits; however, the traditional approach of using birthweight curves is misleading, since a large proportion of preterm births arise from pathological pregnancies. Our aim was to compare the diagnostic accuracies of sonographic versus birthweight curves in diagnosing fetal growth restriction. Our secondary aim was to compare maternal, fetal and neonatal outcome based on these two approaches. METHODS: Retrospective study based on computerized medical records. Included were women with a singleton pregnancy, that underwent fetal biometry between 24 and 36.6 weeks' gestation (January 2010-February 2016) and delivered in our center. Each pregnancy was assigned to one of three groups based on the earliest sonographic estimated fetal weight performed: G1-Appropriate for gestational age, G2-fetal growth restriction based on sonographic but not birthweight curves; or G3-fetal growth restriction based on birthweight growth curves. Demographics, obstetric characteristics, ultrasound data, and neonatal data were retrieved and compared between groups. Primary outcome: rate of small for gestational age neonates in each group. Secondary outcomes were various adverse maternal and neonatal outcomes. RESULTS: Six thousand and five pregnancies met inclusion criteria. Of these 5386 (89.6%) were categorized as G1, 300 (5%) as G2 and 319 (5.3%) as G3. The rate of small for gestational age neonates differed significantly between groups: G1 9.2%, G2 39.7% and G3 70%. Multivariable logistic regression modeling reiterated these rates: the odds ratios for small for gestational age were 6.47 [95% CI 4.99-8.40] and 23.99 [95% CI 18.26-31.51] for G2 and G3 respectively. Prediction of small for gestational age based on sonographic EFW curves increased the sensitivity for detection of SGA from 26% to 41% with a slight decrease in specificity from 98% to 95%, and a decrease of the positive likelihood ratio from 18.4 to 7.7, however there was no significant change in the overall test accurcy; 88.5% to 87.1%.Secondary outcomes also differed between groups: G2 and G3 had similar rates of maternal and neonatal morbidities and most parameters were higher than G1. G2 and G3 showed lower mean gestational age at delivery (36.2 weeks and 35.9 weeks vs.37.8; p < .0001), and higher rates of preterm delivery (40% and 51.7% vs. 21.5%; p < .001), as well as higher rates of intrauterine fetal demise 3% in G2, 6.9% in G3 and 0.9% in G1, p < .0001. CONCLUSION: Pregnancies that are currently managed as appropriate for gestational age based on birthweight curves, but classified as growth restricted when prenatal sonographic curves are used, are associated with higher rates of small for gestational age and poor perinatal outcomes, at rates comparable to pregnancies that are classified as growth restricted based on birthweight curves. Furthermore, applying sonographic curves increases the sensitivity for detection of small for gestational age neonates. Consequently, consideration should be given to the use of sonographic biometry curves for defining fetal growth restriction.

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.

The impact of optimal dating on the assessment of fetal growth.

BACKGROUND: The impact of using the Intergrowth (IG) dating formulae in comparison to the commonly used Robinson dating on the evaluation of biometrics and estimated fetal weight (EFW) has not been evaluated. METHODS: Nationwide cross-sectional study of routine fetal ultrasound biometry in low-risk pregnant women whose gestational age (GA) had been previously assessed by a first trimester CRL measurement. We compared the CRL-based GA according to the Robinson formula and the IG formula. We evaluated the fetal biometric measurements as well as the EFW taken later in pregnancy depending on the dating formula used. Mean and standard deviation of the Z scores as well as the number and percentage of cases classified as <3rd, < 10th, >90th and > 97th percentile were compared. RESULTS: Three thousand five hundred twenty-two low-risk women with scans carried out after 18 weeks were included. There were differences of zero, one and 2 days in 642 (18.2%), 2700 (76.7%) and 180 (5%) when GA was estimated based on the Robinson or the IG formula, respectively. The biometry Z scores assessed later in pregnancy were all statistically significantly lower when the Intergrowth-based dating formula was used (p < 10- 4). Likewise, the number and percentage of foetuses classified as <3rd, < 10th, >90th and > 97th percentile demonstrated significant differences. As an example, the proportion of SGA foetuses varied from 3.46 to 4.57% (p = 0.02) and that of LGA foetuses from 17.86 to 13.4% (p < 10- 4). CONCLUSION: The dating formula used has a quite significant impact on the subsequent evaluation of biometry and EFW. We suggest that the combined and homogeneous use of a recent dating standard, together with prescriptive growth standards established on the same low-risk pregnancies, allows an optimal assessment of fetal growth.

Economic evaluation of a hypothetical integrated energy recovery system for trommel fines.

Trommel fines are a high-ash aggregate waste derived from material recycling facilities (MRFs) and are usually disposed in landfill. Increasing UK landfill tax and environmental concerns, however, calls for a flexible technology that can effectively process and extract valuable energy from trommel fines at high efficiencies. One possible technology is fast pyrolysis coupled to a combined heat and power (pyro-CHP) plant. To determine the feasibility of such technology, an understanding of its economic characteristics is required, in addition to the technical details. This study presents an economic evaluation of a pyro-CHP plant processing three pre-treated trommel fines feedstocks for energy recovery over a 20-year period. The three feedstocks were designated as DPT (from initial separation/size reduction), AW (from ash reduction by washing DPT with water) and AWS (from ash reduction by washing DPT with aqueous surfactant solution). Under all processing capacities (200 kg/h to 2000 kg/h) total revenues from the pyro-CHP system were higher than landfill costs, but only became profitable at 2000 kg/h processing capacity for the DPT feedstock. Further analysis showed positive net present values (NPV) only for AW and AWS, e.g. at 2000 kg/h capacities, with payback periods of about 14 years compared to 35 years for DPT at a fixed CHP efficiency of 60% and 20% internal rate of return (IRR). Sensitivity analysis carried out using different values of IRR and CHP efficiencies, confirmed the superior economic performance of the washed feedstocks over DPT, with payback periods reducing to about 6 years in some cases.

Predictive value of prenatal ultrasound parameters for dichorionic growth discordant twins.

BACKGROUND: Twin growth discordance was demonstrated to be a risk factor for adverse perinatal outcomes, and prenatal ultrasonographic methods were utilized to predict twin growth discordance to improve outcomes. The results currently reported are not consistent due to the poor unified parameters and gestational durations. METHODS: A total of 71 dichorionic twins with growth discordance and 346 dichorionic twins with normal growth were respectively included in the retrospective cohort study. The weight discordance of more than 25% was defined as a "growth discordant twin". The clinical baseline information, maternal outcomes, twin birth weights and fetal growth parameters (which were measured by ultrasound) were compared between the two groups from early gestation to late gestation. Multiple logistic regression and receiver operating characteristic curves were adopted to evaluate the predictive value of the growth parameters. RESULTS: Compared with normal dichorionic twins, the clinical baseline conditions were similar in the twins those finally developed growth discordance. The fetal growth parameters and the deepest volume pocket of amniotic fluid in early and mid-pregnancy showed no obvious predictive values. The fetal growth parameters in late pregnancy showed predictive values, especially the discordance of estimated fetal weight (EFW) in the early third-trimester (P < 0.001, area under the curve, 0.822; the cut-off value, 20%; sensitivity, 66.67%; specificity, 91.30%; positive predictive value, 88.46%). CONCLUSION: Two assessment approaches were suggested and adopted to predict twin growth discordance in the current study. Twin growth should be assessed longitudinally and dynamically. Normal twins may show growth imbalance in the early stage. The discordance of EFW in late pregnancy may be a useful indicator for a growth discordance of more than 25%, which is required further confirmation.

Performance of different fetal growth charts in prediction of large-for-gestational age and associated neonatal morbidity in multiethnic obese population.

OBJECTIVES: To examine the performance of different fetal growth charts in the prediction of large-for-gestational age (LGA) and associated neonatal morbidity at term in a multiethnic, obese population. METHODS: This was a retrospective cohort study of 253 non-anomalous, singleton, term pregnancies that underwent serial third-trimester ultrasound scans due to maternal body mass index ≥ 35 kg/m2 . We compared the performance of the Hadlock, Gestation Related Optimal Weight (GROW), INTERGROWTH-21st (IG-21), World Health Organization (WHO) and Fetal Medicine Foundation (FMF) fetal growth reference charts in the prediction of LGA at birth, defined as birth weight > 90th percentile, and neonatal morbidity, defined as a composite of neonatal intensive care unit admission or 5-min Apgar score < 7. RESULTS: In the study population, 53 (20.9%) infants were born LGA, 27 (10.7%) experienced neonatal morbidity and nine (3.6%) were LGA with associated neonatal morbidity. The Hadlock and GROW charts showed similar performance in predicting LGA, with sensitivity of 66.0% for both and specificity of 82.5% and 83.5%, respectively. The positive likelihood ratios (LR+) were 3.77 (95% CI, 2.64-5.40) and 4.00 (95% CI, 2.77-5.78), respectively. The IG-21, WHO and FMF charts performed similarly and had higher sensitivity of about 85%, with specificity between 66% and 72%. LR+ was 2.74 (95% CI, 2.16-3.47), 2.50 (95% CI, 2.00-3.12) and 3.03 (95% CI, 2.36-3.89), respectively. All charts had high sensitivity for predicting neonatal morbidity associated with LGA, with LR+ ranging between 2.35 and 3.61. CONCLUSIONS: In our multiethnic, obese population, all fetal growth charts performed well in predicting LGA and associated neonatal morbidity. However, the choice of fetal reference chart is likely to affect intervention rates. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Effect of oligohydramnios on the accuracy of sonographic foetal weight estimation in at term pregnancies.

OBJECTIVE: Ultrasound estimation of foetal weight is a very important aspect of antenatal care. The role of amniotic fluid volume as a potential factor which may impede the relevance of ultrasonographic foetal weight estimation is still questionable. The aim of our study was to evaluate the impact of isolated oligohydramnios on the accuracy of ultrasound foetal weight estimation in at term pregnancies when examination was performed within 48 h before delivery. MATERIALS AND METHODS: The retrospective cohort study included 1831 women with low-risk, singleton, at term pregnancy. Estimated foetal weight (EFW) was calculated using Hadlock-4 formula. Exclusion criteria consisted of multiple pregnancies, active phase of labour, preeclampsia, foetal growth restriction, foetal anomalies, gestational diabetes mellitus and the evidence of intrauterine infection. Isolated oligohydramnios was defined as Amniotic Fluid Index (AFI) ≤50 mm without any other foetal anomalies. EFW and actual birth weight (ABW) were compared by calculation of: absolute error (AE), absolute percentage error (APE) and substantial error (SE) = APE >10%. RESULTS: Participants were divided into 2 groups: Group 1: patients with normal AFI (50 ≤ AFI ≤250 mm; n = 1602) and Group 2: (isolated oligohydramnios, n = 229). There were not observed statistically significant differences between mean ABW and mean EFW in both groups (Group 1: p = 0.525; Group 2: p = 0.317). Mean AE in Group 1 was 221.8 g and 223.1 g in Group 2 (p = 0.919). Mean APE was 6.54% and 6.64% in Group 1 and 2 respectively (p = 0.816). SE ratio was 21.9% in Group 1 and 19.2% in Group 2. Underestimation to overestimation ratio in Group 1 was 1.01 and 0.84 in Group 2. CONCLUSIONS: Amniotic fluid volume has limited impact on ultrasound foetal weight estimation. In oligohydramnios group there might be a tendency of overestimation of neonatal ABW.

Changes in composition and lead speciation due to water washing of air pollution control residue from municipal waste incineration.

Changes in elemental and mineralogical composition, and lead speciation, of air pollution control residue (APCR) from municipal solid waste incineration, due to treatment by water washing, were investigated in this work and are reported in the context of a review of the literature. Water washing was shown to substantially modify the nature of APCR by: 1) removing 23% dry mass soluble salts to disagglomerate particles and significantly reduce concentrations of the associated major elements, and increase concentrations of insoluble matrix elements and potential pollutants; and 2) respeciating elements to form new phases. X-ray absorption near edge spectroscopy (XANES) showed that the 500 mg/kg of Pb in raw and washed APCR were comprised mainly of Pb-glass, with some PbSO4, and small amounts of PbO and PbCl2. Semi-quantitative linear combination fitting suggests that the glass in the APCR may be unstable and release Pb under the alkaline pH of water washing, to reprecipitate as PbO. Chemical analysis suggests that some Pb may be removed by washing. Scientific understanding of the composition of raw and washed APCR, and particularly the speciation of potentially toxic metals, such as Zn and Pb, can help in developing effective element recovery and residue treatment, utilization or disposal strategies.

The value of ultrasound in predicting isolated inter-twin discordance and adverse perinatal outcomes.

PURPOSE: To investigate the value of ultrasound approaching delivery to predict isolated inter-twin discordance and adverse perinatal outcomes. METHODS: We retrospectively included twin pregnancies with sonography approaching delivery in ten maternal-foetal medicine centres in China from 2013 to 2014. Estimated foetal weight (EFW) and inter-twin EFW disparity (EFWD) were calculated based on biometry parameters. Percentage errors between EFW and actual birthweight or between EFWD and actual inter-twin disparity were calculated. ROC curves and multiple logistic regression were applied to evaluate the ability of EFWD to predict inter-twin disparity ≥ 25%, stillbirth, asphyxia and admission to a neonatal intensive unit (NICU). Chorionicity-stratified analysis was further performed. RESULTS: Two hundred sixty-six monochorionic and 760 dichorionic twin pregnancies were analysed. The percentage errors in foetal weight estimations were 7-13%, whereas percentage errors in the estimation of inter-twin disparity were nearly 100%. Among eight formulas, Hadlock1 performed best, with a detectable rate of 65% and a false positive rate of 5% when predicting inter-twin disparity ≥ 25%. EFWD ≥ 22% was strongly associated with stillbirth (OR = 4.17, 95% CI 1.40-12.40) and NICU admission (OR = 3.48, 95% CI 2.03-5.97) after adjustment for gestational age, parity and abnormal umbilical systolic/diastolic ratio. Ultrasound had better predictive ability in monochorionic twins. CONCLUSION: The predictive value of ultrasound for isolated inter-twin discordance and adverse perinatal outcomes was limited, which was possibly due to the magnifying of systematic errors in the disparity estimation compared with weight estimation. Despite this, abnormal biometry was an independent contributor for the poor prognosis of neonates.

[Report from the CFEF seminar on fetal biometry (June 2017)]. / Compte rendu du séminaire de travail du Collège français d'échographie fœtal (CFEF) sur les référentiels et standards de biométrie fœtale. Juin 2017.

This article reports the conclusions and recommendations resulting from the seminar organized in Paris on June 15, 2017 by the scientific committee of the French College of Fetal Ultrasound (CFEF). The purpose of this meeting was to audit the practices in screening for SGA and IUGR fetuses in France and to discuss ways to improve ultrasound screening. A review of charts, references, standards and common practices was performed. The potential new biometric tools applicable in France were reviewed and analyzed. Eventually, options and recommendations for improvement are proposed.

Spacecraft surface charging within geosynchronous orbit observed by the Van Allen Probes.

Using the Helium Oxygen Proton Electron (HOPE) and Electric Field and Waves (EFW) instruments from the Van Allen Probes, we explored the relationship between electron energy fluxes in the eV and keV ranges and spacecraft surface charging. We present statistical results on spacecraft charging within geosynchronous orbit by L and MLT. An algorithm to extract the H+ charging line in the HOPE instrument data was developed to better explore intense charging events. Also, this study explored how spacecraft potential relates to electron number density, electron pressure, electron temperature, thermal electron current, and low-energy ion density between 1 and 210 eV. It is demonstrated that it is imperative to use both EFW potential measurements and the HOPE instrument ion charging line for examining times of extreme spacecraft charging of the Van Allen Probes. The results of this study show that elevated electron energy fluxes and high-electron pressures are present during times of spacecraft charging but these same conditions may also occur during noncharging times. We also show noneclipse significant negative charging events on the Van Allen Probes.

[Detection of small for gestational age fetuses during third trimester ultrasound. A monocentric observational study]. / Détection des fœtus petits pour l'âge gestationnel lors de l'échographie du troisième trimestre. Étude observationnelle monocentrique.

OBJECTIVES: Fetus small for gestational age (SGA) screening rate is evaluated around 21,7 % in France. Recommendations were developed to improve the efficiency of ultrasound conducted in the third trimester (T3), because neonatal consequences can be significant. This study aims to evaluate screening of SGA during T3 ultrasound and to describe causes for failure and differences with the recommendations of CNGOF. METHODS: All children born between 2011 and 2012 with a birth weight below the 3rd percentile were included in this observational, retrospective, monocentric study. We noted that the diagnosis of SGA was placed on file. Then, as recommended by the CNGOF, we calculated estimated fetal weight (EFW) with Hadlock 3 and Hadlock 4, and the corresponding percentiles, using the biometrics from the ultrasound report. We thus could evaluate a new screening rate with SGA fetus identified through this technique. RESULTS: A total of 142 patients were included. By calculating correctly all EFW and checking abdominal circumference percentiles, the screening rate of SGA fetuses with T3 ultrasound increased from 40 % to 50 % and the overall screening rate (clinical and ultrasound) from 54 % to 66 %. CONCLUSION: By following the recommendations we found a real improvement in fetal SGA screening rates to T3 ultrasound with a potential benefit for their care.

The association between second trimester estimated fetal weight and small for gestational age at birth.

OBJECTIVE: To analyze diagnostic accuracy of second trimester ultrasound fetal growth parameters as predictors of small for gestational age (SGA) birth weight. METHODS: We reviewed the fetal biometry from 714 consecutive patients with second trimester ultrasounds. The estimated fetal weight (EFW) and abdominal circumference (AC) percentiles were tested as predictors of SGA at birth (<10‰). RESULTS: 87 (12.2%) patients had an SGA baby. Patients with a second trimester EFW ≤25‰ were significantly more likely to have SGA at birth (24.2% versus 10.3%, p < 0.001). Similar results were seen for women with second trimester AC ≤25‰ (likelihood of SGA 21.9% versus 11.2%, p = 0.013). A second trimester EFW ≤25‰ was a better predictor of SGA at birth than a second trimester EFW ≤ 10‰ (Positive likelihood ratio 2.30 versus 2.09). In the second trimester, only 9 (1.3%) patients had an EFW 0-10‰, only 43 (6%) patients had an EFW 11-20‰, and only 46 (6.4%) patients had an EFW 91-99‰. Each other EFW centile had more than 10% of the patients. CONCLUSIONS: The incidence of second trimester EFW or AC ≤10‰ is less common than expected from standard tables. An EFW ≤25‰ and an AC ≤25‰ should be considered the second trimester marker for risk of SGA at birth. However, due to the low likelihood ratio of, it is not clear if second trimester ultrasound should be used as a predictor of SGA at birth.