Measurement Of Fetal Abdominal Circumference Research Articles

Bringing precision medicine to the management of pregnancy in women with glucokinase-MODY: a study of diagnostic accuracy and feasibility of non-invasive prenatal testing.

In pregnancies where the mother has glucokinase-MODY (GCK-MODY), fetal growth is determined by fetal genotype. When the fetus inherits a maternal pathogenic GCK variant, normal fetal growth is anticipated, and insulin treatment of maternal hyperglycaemia is not recommended. At present, fetal genotype is estimated from measurement of fetal abdominal circumference on ultrasound. Non-invasive prenatal testing of fetal GCK genotype (NIPT-GCK) using cell-free DNA in maternal blood has recently been developed. We aimed to compare the diagnostic accuracy of NIPT-GCK with that of ultrasound, and determine the feasibility of using NIPT-GCK to guide pregnancy management. We studied an international cohort of pregnant women with hyperglycaemia due to GCK-MODY. We compared the diagnostic accuracy of NIPT-GCK with that of measurement of fetal abdominal circumference at 28 weeks' gestation (n=38) using a directly genotyped offspring sample as the reference standard. In a feasibility study, we assessed the time to result given to clinicians in 43 consecutive pregnancies affected by GCK-MODY between July 2019 and September 2021. In terms of diagnostic accuracy, NIPT-GCK was more sensitive and specific than ultrasound in predicting fetal genotype (sensitivity 100% and specificity 96% for NIPT-GCK vs sensitivity 53% and specificity 61% for fetal abdominal circumference 75th percentile). In terms of feasibility, a valid NIPT-GCK fetal genotype (≥95% probability) was reported in all 38 pregnancies with an amenable variant and repeated samples when needed. The median time to report was 5 weeks (IQR 3-8 weeks). For the 25 samples received before 20 weeks' gestation, results were reported at a median gestational age of 20 weeks (IQR 18-24), with 23/25 (92%) reported before 28 weeks. Non-invasive prenatal testing of fetal genotype in GCK-MODY pregnancies is highly accurate and is capable of providing a result before the last trimester for most patients. This means that non-invasive prenatal testing of fetal genotype is the optimal approach to management of GCK-MODY pregnancies.

Intra-abdominal umbilical venous diameter and abdominal circumference discordance at 15-20weeks' gestation: simple markers in transverse abdominal plane to predict adverse pregnancy outcomes in monochorionic diamniotic twins.

This study aimed to investigate the association between simple markers in fetal abdominal plane, intra-abdominal umbilical venous diameter (DIUV) and abdominal circumference (AC) discordance at 15-20weeks' gestation, and adverse pregnancy outcomes in monochorionic diamniotic (MCDA) twins. We performed a retrospective analysis of MCDA twins with two live fetuses examined at 15-20weeks from Jun 2020 to Dec 2021 at Beijing Obstetrics and Gynecology Hospital. Measurement of fetal AC and DIUV was performed according to standard protocols. Twin pregnancies with major fetal structural anomalies, chromosomal abnormalities, miscarriage, and twin reversed arterial perfusion sequence were excluded. DIUV and AC discordance in MCDA twins with an adverse pregnancy outcome was compared with a normal pregnancy outcome. Furthermore, the performance of DIUV and AC discordance in predicting adverse pregnancy outcomes in MCDA twins was assessed. A total of 105 women with MCDA twin pregnancies were enrolled, contributing 179 visits. Adverse pregnancy outcomes occurred in 33.3% (35/105) of cases in our study. The intra-observer and inter-observer intraclass correlation coefficient (ICC) of both AC and DIUV were very good or excellent. There was no statistical difference in AC and DIUV discordance (%) between 15-16, 17-18, and 19-20weeks (χ2 = 3.928, P = 0.140; χ2 = 2.840, P = 0.242). Both AC and DIUV discordance were greater in twins with adverse pregnancy outcomes than that in twins with normal pregnancy outcome at each pregnancy periods. Both AC discordance (OR 1.2, 95% CI 1.1-1.3) and DIUV discordance (OR 1.2, 95% CI 1.1-1.2) were associated with adverse pregnancy outcomes. The AUC for predicting adverse pregnancy outcomes by AC discordance was 0.75 (95% CI 0.68-0.83), with a sensitivity of 58.7% (95% CI 51.9-64.5) and a specificity of 86.2% (95% CI 81.7-88.4). The AUC for predicting adverse pregnancy outcomes by DIUV was 0.78 (95% CI 0.70-0.86), with sensitivity and specificity of 65.1% (95% CI 58.1-70.3) and 86.2% (95% CI 81.7-88.4), respectively. The AC discordance and DIUV discordance could predict adverse pregnancy outcomes in MCDA twins. When these simple markers occurred, intensive surveillance was recommended.

Flexible treatment of gestational diabetes mellitus adjusted according to intrauterine fetal growth versus treatment according to strict maternal glycemic parameters: a randomized clinical trial

IntroductionTo compare the conventional treatment of gestational diabetes mellitus (GDM) with flexible treatment according to the measurement of fetal abdominal circumference (AC) in daily clinical practice.Research design and methodsTwo hundred...

A comparison of four fetal biometry growth charts within an Australian obstetric population.

The aim of this study was to investigate the applicability of four existing fetal growth charts to a local tertiary hospital obstetric population. Four existing fetal growth charts (the Raine study reference charts, INTERGROWTH-21st charts, World Health Organization (WHO) fetal growth study charts and Australasian Society for Ultrasound in Medicine (ASUM) endorsed Campbell Westerway charts were compared using data from 11651 singleton pregnancy ultrasound scans at King Edward Memorial Hospital (KEMH). The 3rd, 10th, 50th 90th and 97th percentile curves for abdominal circumference (AC) biometry for the KEMH data were calculated and the four primary correlation parameters from fitted 3rd order polynomials (a, b, c and d) were used to generate like-for-like comparisons for all charts. The overall comparisons showed a significant variation with different growth charts, giving different percentiles for the same fetal AC measurement. INTERGROWTH-21st percentile curves tended to fall below those of other charts for AC measurements. Both the Raine Study charts and ASUM charts were the charts of closest overall fit to the local data. Our data show the Raine Study charts are the most appropriate for our population compared with the other three charts assessed suggesting the 'one size fits all' model may not be appropriate. However, additional analysis of biometry measurements, primarily AC, is needed to address the deficiency of data at 14-18 weeks gestation which exists for the Raine Study data.A reasonable alternative may be to adopt the WHO charts with local calibration (including the 14 - 18 week gestation period).

Serial Measurements of Fetal Head Circumference and Abdominal Circumference to Predict Fetal Growth Restriction in a Sri Lankan Study Population

Serial Measurements of Fetal Head Circumference and Abdominal Circumference to Predict Fetal Growth Restriction in a Sri Lankan Study Population

Fetal Thoracic Circumference and Lung Volume and Their Relation to Fetal Size and Pulmonary Artery Blood Flow.

Research on early origins of lung disease suggests the need for studying the relationships of thoracic and lung size with fetal size and pulmonary circulation. The primary aim of this study is therefore to explore the associations between fetal thoracic circumference, lung volume, and fetal size. We also aim to assess if lung volume and thoracic circumference are associated with fetal pulmonary artery blood flow velocity measures. Cross-sectional assessment of singleton pregnancies from the general population (n=447) at 30 gestational weeks (GW) was performed using ultrasound measurement of fetal thoracic circumference, lung volume, head and abdominal circumference, and femur length. We obtained Doppler blood flow velocity measures from the proximal branches of the fetal pulmonary artery. Associations between variables were studied using Pearson's correlation and multiple linear regression analyses. Both thoracic circumference and lung volume correlated with fetal size measures, ranging from r=0.64 between thoracic circumference and abdominal circumference, to r=0.28 between lung volume and femur length. Adjustment for gestational age, maternal nicotine use, pre-pregnancy body mass index, and fetal sex marginally influenced the associations with abdominal circumference. The correlations of thoracic circumference and lung volume with pulmonary artery blood flow velocity measures were weak (r ≤ 0.17). We found moderate to low correlation between thoracic circumference, lung volume, and fetal size at 30 GW. The closest relationship was with the abdominal circumference. We found low correlations of thoracic circumference and lung volume with pulmonary artery blood flow velocity measures.

Accuracy of estimated fetal weight assessment in fetuses with abdominal wall defects

Gastroschisis and omphalocele are congenital abdominal wall defects in which the bowel and other abdominal contents extrude from the fetal abdominal cavity. Standard formulas for estimated fetal weight using ultrasound include fetal abdominal circumference measurement and have a range of error of approximately 10%. It is unknown whether the accuracy of estimated fetal weight assessment is compromised in fetuses with abdominal wall defects because of the extrusion of abdominal contents. This study aimed to assess the accuracy of standard estimated fetal weight assessment in fetuses with abdominal wall defects by comparing prenatal assessment of fetal weight with actual birthweight. A retrospective cohort study of fetuses diagnosed with gastroschisis or omphalocele was performed at a single center from 2012 to 2018. Fetuses with additional anomalies or confirmed chromosome abnormalities were excluded. Estimated fetal weight was calculated using the Hadlock formula. Published estimates of fetal growth rate were used to establish a projected estimated fetal weight at birth from the final growth ultrasound, and the percent difference between projected estimated fetal weight at birth and actual birthweight was calculated. The Wilcoxon rank-sum test was used to examine the difference between projected estimated fetal weight and actual birthweight. We had complete data for 112 fetuses with abdominal wall defects, including 85 with gastroschisis and 27 with omphalocele. The median (interquartile range) projected estimated fetal weight was similar to median birthweight, at 2283 g (interquartile range, 2000-2810) and 2306 g (interquartile range, 1991-264), respectively, which did not represent a statistically significant difference between projected estimated fetal weight and actual birthweight (P=.32). The median percent error was 6.8 (3.1-12.8). In addition, we did not find any statistical difference between projected estimated fetal weight and actual birthweight in patients with gastroschisis (P=.52) or omphalocele (P=.35) individually. Estimated fetal weight was underestimated in most cases (n=68 [60.7%]). In fetuses with abdominal wall defects, standard measurement of fetal weight shows an accuracy that is at least comparable with previously established margins of error for ultrasound assessment of fetal weight. Standard estimated fetal weight assessment remains an appropriate method of estimating fetal weight in these fetuses.

Ultrasound evaluation of the fetal fat tissue, heart, liver and umbilical cord measurements in pregnancies complicated by gestational and type 1 diabetes mellitus: potential application in the fetal birth-weight estimation and prediction of the fetal macrosomia

BackgroundThe aim of the study was to evaluate the ultrasound-derived measurements of the fetal soft-tissue, heart, liver and umbilical cord in pregnancies complicated by gestational (GDM) and type 1 diabetes mellitus (T1DM), and further to assess their applicability in the estimation of the fetal birth-weight and prediction of fetal macrosomia.MethodsMeasurements were obtained from diet-controlled GDM (GDMG1) (n = 40), insulin-controlled GDM (GDMG2) (n = 40), T1DM (n = 24) and healthy control (n = 40) patients. The following parameters were selected for analysis: fetal sub-scapular fat mass (SSFM), abdominal fat mass (AFM), mid-thigh fat/lean mass (MTFM/MTLM) and inter-ventricular septum (IVS) thicknesses, heart and thorax circumference and area (HeC/HeA; ThC/ThA), liver length (LL), umbilical cord/vein/arteries circumference and area (UmC/UmA; UvC/UvA; UaC/UaA) together with total umbilical vessels (UveA) and Wharton's jelly area (WjA). Regression models were created in order to assess the contribution of selected parameters to fetal birth-weight (FBW) and risk of fetal macrosomia.ResultsMeasurements of the fetal SSFM, AFM, MTFM, MTFM/MTLM ratio, HeC, HeA, IVS, LL, UmC, UmA, UaC, UaA, UveA and WjA were significantly increased among patients with GDMG2/T1DM as compared to GDMG1 and/or control groups (p < .05). The regression analysis revealed that maternal height as well as fetal biparietal diameter, abdominal circumference (AC), AFM and LL measurements were independent predictors of the FBW (p < .05). In addition, increase in the fetal AFM, AC and femur length (FL) was associated with a significant risk of fetal macrosomia occurrence (p < .05). The equation developed for the FBW estimation [FBW(g) = − 2254,942 + 17,204 * FL (mm) + 105,531 * AC (cm) + 131,347 * AFM (mm)] provided significantly lower mean absolute percent error than standard formula in the sub-group of women with T1DM (5.7% vs 9.4%, p < .05). Moreover, new equation including AC, FL and AFM parameters yielded sensitivity of 93.8%, specificity 77.7%, positive predictive value 54.5% and negative predictive value of 97.8% in the prediction of fetal macrosomia.ConclusionsUltrasound measurements of the fetal soft tissue, heart, liver and umbilical cord are significantly increased among women with GDM treated with insulin and T1DM. In addition to standard biometric measurements, parameters, such as AFM, may find application in the management of diabetes-complicated pregnancies.

574 Fetal abdominal circumference as an early marker in prediction of small for gestational age newborns

This study aims to evaluate the relationship of the fetal abdominal circumference (AC) and the subsequent development of fetal growth restriction (FGR) in small for gestational age (SGA) newborns. This is a retrospective cohort study of singleton fetuses diagnosed with antenatal FGR (EFW < 10th percentile) during ultrasound between 2012 and 2020. Time from diagnosis of AC < 10th percentile to time of diagnosis of FGR and time to delivery were calculated. Primary outcome was SGA newborns (birthweight < 5th percentile). Secondary outcomes included fetal umbilical artery Doppler, maternal comorbid disorders such as hypertension and autoimmune disease, and newborn outcomes. Abnormal umbilical artery Doppler was defined as an S/D ratio >95th percentile for GA, absent end diastolic flow or reverse end diastolic flow. Statistical analyses, including Chi square and logistic regression modeling, were performed with significance levels of <0.05. Of 231 women given an antenatal diagnosis of FGR, there were 182 (79%) SGA newborns and 49 (21%) non-SGA newborns. Both groups were similar in age, parity, ethnicity, substance use disorder, gestational age at delivery, oligohydramnios, preeclampsia, and maternal comorbidities. Fetal AC <10th percentile preceded ultrasound diagnosis of FGR in SGA newborns more frequently than non-SGA newborns (46% v 29%; p=0.03). Time from identification of an AC <10th percentile to diagnosis of FGR averaged 6.7±4.9 weeks. Antenatal abnormal umbilical artery Doppler occurred more frequently in SGA newborns compared with non-SGA newborns (92% v 8%; p=0.002). In logistic regression, the antenatal variables most likely to predict an SGA newborn included fetal AC <10th percentile preceding FGR (OR 2.27; 95%CI: 1.09-4.71) and abnormal umbilical artery Doppler (OR 4.41; 95%CI: 1.7 –11.4). (Table 1) Measurement of fetal AC <10th percentile on antenatal ultrasound independently predicts development of subsequent FGR and SGA newborns. When an ultrasound measurement of the AC is <10th percentile, further monitoring should be recommended.

Assessment of Transcerebellar Diameter Accuracy in Detection of Gestational Age in Third Trimester in Cases of Intrauterine Growth Restriction

Background: Intrauterine Growth Restriction (IUGR) is defined as decreased fetal birth weight less than 10th percentile as regard to gestational age also diagnosed when there is a delay more than 2 weeks in a serial ultrasound monitoring of fetal gestational age. Objective: The aim of the work was to evaluate accuracy of transcerebellar diameter (TCD) in detection of gestational age in pregnancies with intrauterine growth restriction IUGR. Patients and Methods: Case-Control study was carried out on 52 women with normally progressing pregnancies during the third trimesters, with gestational ages between 27 and 37 weeks of gestation came to outpatient clinic of department of Obstetrics and Gynecology, Zagazig General Hospital and Zagazig University Hospital from June 2019 to March 2020, of them, 26 subjects were normal pregnancies and 26 subjects diagnosed as IUGR in 3rd trimester at gestational age (27week to 37 week). Trans-abdominal ultrasound was performed on all subjects; Fetal TCD was measured using the widest diameter of the cerebellum, measurement of fetal Bi-Parietal Diameter (BPD), Abdominal Circumference (AC), and Femur Length (FL). Results: There was statistically significant difference between gestational age (GA) by Last Menstrual Period (LMP) and sonar parameters at normal group but highest was TCD with P value 0.000 but in IUGR group only TCD, AC and FL were significantly positive correlated with GA; and TCD were highly significant. Conclusions: It could be concluded that the TCD measurement appears to be an accurate predictor of gestational age, even in the third trimester of pregnancy.

Assessment of Transcerebellar Diameter Accuracy in Detection of Gestational Age in Third Trimester in Cases of Intrauterine Growth Restriction

Background: Intrauterine Growth Restriction (IUGR) is defined as decreased fetal birth weight less than 10th percentile as regard to gestational age also diagnosed when there is a delay more than 2 weeks in a serial ultrasound monitoring of fetal gestational age. Objective: The aim of the work was to evaluate accuracy of transcerebellar diameter (TCD) in detection of gestational age in pregnancies with intrauterine growth restriction IUGR. Patients and Methods: Case-Control study was carried out on 52 women with normally progressing pregnancies during the third trimesters, with gestational ages between 27 and 37 weeks of gestation came to outpatient clinic of department of Obstetrics and Gynecology, Zagazig General Hospital and Zagazig University Hospital from June 2019 to March 2020, of them, 26 subjects were normal pregnancies and 26 subjects diagnosed as IUGR in 3rd trimester at gestational age (27week to 37 week). Trans-abdominal ultrasound was performed on all subjects; Fetal TCD was measured using the widest diameter of the cerebellum, measurement of fetal Bi-Parietal Diameter (BPD), Abdominal Circumference (AC), and Femur Length (FL). Results: There was statistically significant difference between gestational age (GA) by Last Menstrual Period (LMP) and sonar parameters at normal group but highest was TCD with P value 0.000 but in IUGR group only TCD, AC and FL were significantly positive correlated with GA; and TCD were highly significant. Conclusions: It could be concluded that the TCD measurement appears to be an accurate predictor of gestational age, even in the third trimester of pregnancy.

Fetal overgrowth in pregnancies complicated by diabetes: validation of a predictive index in an external cohort.

To assess validity of a fetal overgrowth index in an external cohort of women with diabetes in pregnancy METHODS: We performed a retrospective analysis of data derived from women with singleton gestations complicated by diabetes who delivered January 2015-June 2018. The following index variables were used to calculate risk of fetal overgrowth as defined by a customized birthweight ≥ 90th centile: age, history of fetal overgrowth in a prior pregnancy, gestational weight gain, fetal abdominal circumference measurement and fasting glucose between 24 and 30weeks. In our validation cohort, 21% of 477 pregnancies were complicated by fetal overgrowth. The predictive index had a bias-corrected bootstrapped area under receiver operating characteristic curve of 0.90 (95% CI 0.86-0.93). 55% of the cohort had a low-risk index (≤ 3) which had a negative predictive value of 97% (95% CI 94-98%), while 18% had a high-risk index (≥ 8) that had a positive predictive value of 74% (95% CI 66-81%). The fetal overgrowth index incorporates five factors that are widely available in daily clinical practice prior to the period of maximum fetal growth velocity in the third trimester. Despite substantial differences between our cohort and the one studied for model development, we found the performance of the index was strong. This finding lends support for the general use of this tool that may aid counseling and allow for targeted allocation of healthcare resources among women with pregnancies complicated by diabetes.

Fetal biometry assessment with Intergrowth 21st\u2019s and Salomon\u2019s equations in rural Burkina Faso

BackgroundUltrasound scanning during the 2nd or the 3rd trimester of pregnancy for fetal size disturbances screening is heavily dependent of the choice of the reference chart. This study aimed to assess the agreement of Salomon and the Intergrowth 21st equations in evaluating fetal biometric measurements in a rural area of Burkina Faso, and to measure the effect of changing a reference chart.MethodsData collected in Nazoanga, Burkina Faso, between October 2010 and October 2012, during a clinical trial evaluating the safety and efficacy of several antimalarial treatments in pregnant women were analyzed. We included singleton pregnancies at 16–36 weeks gestation as determined by ultrasound measurements of fetal bi-parietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL). Expected mean and standard deviation at a given gestational age was computed using equations from Salomon references and using Intergrowth 21st standard. Then, z-scores were calculated and used subsequently to compare Salomon references with Intergrowth 21st standards.ResultsThe analysis included 276 singleton pregnancies.Agreement was poor except for HC: mean difference − 0.01, limits of agreement − 0.60 and 0.59. When AC was used as a surrogate of fetal size, switching from the reference of Salomon to the standards of Intergrowth 21st increased ten times the proportion of fetuses above the 90th percentile: 2.9 and 31.2%, respectively.Mean differences were larger in the third trimester than in the second trimester. However, agreement remained good for HC in both trimesters.Difference in the proportion of AC measurements above the 90th percentile using Salomon and Intergrowth 21st equations was greater in the second trimester (2.6 and 36.3%, respectively) than in the third trimester (3.5 and 19.8%, respectively). The greatest difference between the two charts was observed in the number of FL measurements classified as large in the second trimester (6.8 and 54.2%, using Salomon and Intergrowth 21st equations, respectively).ConclusionThe agreement between Intergrowth 21st and Salomon equations is poor apart from HC. This would imply different clinical decision regarding the management of the pregnancy.

Maternal irisin level in last trimester isolated intrauterine growth-restriction

Purpose Intrauterine Growth Restriction (IUGR) is the inability of the fetus to achieve the biologically accessible growth potential. Irisin is a recently discovered adipomyokine with a crucial role in energy metabolism. Our current study aimed to investigate the relationship between the isolated IUGR in the third trimester and maternal serum irisin level. Materials and methods This prospective case-control study included total 137 pregnant women who were between the 24th and 39th gestational weeks and who applied to the University of Health Sciences, Ankara Zekai Tahir Burak Women's Health Training and Research Center, between 2016 October-2017 May. The Study Group consisted of 68 pregnant women who were diagnosed with Isolated IUGR with Estimated Fetal Weight (EFW) <10th percentile. The Control Group consisted of 69 low-risk uncomplicated pregnant women, matched with the Study Group in terms of gestational week, and with EFW between 10th and 90th percentiles. Demographic data, clinical findings, fetal Doppler parameters, and obstetric-neonatal outcomes were evaluated. Maternal serum irisin levels were measured by ELISA (Enzyme-Linked Immunosorbent Assay) Method and compared between the groups. Results Maternal serum irisin level was found to be significantly lower in IUGR Group as compared to the Control (3.83 ng/ml vs. 4.78 ng/ml, p < .001, respectively). There was a positive correlation between maternal serum irisin level and duration of pregnancy, the weight gain during pregnancy, birth weight, fetal abdominal circumference measurement and cerebroplacental ratio (r = 0.18, p = .03; r = 0.17, p = .04; r = 0.37, p < .001; r = 0.35, p < .001; r = 0.27, p = .001, respectively). Binary Logistic Regression Analysis showed that maternal serum irisin level is an independent estimator of IUGR [OR %95 CI: 8.33 (3.22 − 25.01)]. AUC (Area Under the Curve) analysis of maternal irisin for IUGR estimation was 0.75 (p < .001, 95% CI = 0.67 − 0.82). The optimal cutoff value was below 3.86 ng/ml for maternal irisin level with a sensitivity of 54.41% and a specificity of 88.41%, positive predictive value of 82.22% and negative predictive value of 66.30%. Conclusion Low level of maternal serum irisin in pregnancies with isolated IUGR was consistent with the role of irisin in metabolic pathways and with the increased risk of metabolic diseases in the future life of IUGR fetuses and their mothers.

Midtrimester Ultrasound Predictors of Small-for-Gestational-Age Neonates.

To determine whether a specific estimated fetal weight (EFW) or abdominal circumference (AC) measurement percentile at the 18-to 24-week ultrasound (US) examination is associated with a small-for-gestational-age (SGA) neonate. A retrospective case-control study was conducted including women with uncomplicated singleton gestations who delivered a term SGA neonate identified as having a birth weight (BW) below the 10th percentile on the Olsen growth curve and had an 18- to 24-week US examination in our database. The study period was October 2011 to January 2018. A similar number of control charts were requested randomly over the same time with BW in the 10th to 90th percentiles, all which had an 18-to 24-week US examination in our database. After all neonates meeting BW criteria were identified, a chart review was performed to specifically evaluate biometric parameters from the US at 18 to 24 weeks to determine a potential correlation with the EFW percentile and AC percentile. Pregnancy, neonatal outcomes, and maternal demographic characteristics were collected. A total of 549 term neonates with a BW below the 10th percentile, and 593 control term neonates with BW in the of 10th to 90th percentiles were reviewed. Our analyses revealed that the AC and EFW percentiles were poor predictors of BW (<10th percentile; areas under the receiver operating characteristic curves, 0.68 and 0.69, respectively). A similar low ability of AC and EFW to predict BW below the 5th percentile was noted. (1) No tipping point or cutoff for the EFW or AC percentile at the 18- to 24-week US examination was identified to predict a term SGA neonate. (2) These data are helpful when counseling women in midgestation about specific parameters, their importance, and the potential need for follow up imaging.

Sonographic and other nonglycemic factors can predict large-for-gestational-age infants in diet-managed gestational diabetes mellitus: A retrospective cohort study.

Gestational diabetes mellitus (GDM) is one of the most common complications of pregnancy. Left untreated or poorly controlled, GDM results in adverse infant outcomes such as large for gestational age (LGA). This study aims to identify nonglycemic maternal and fetal factors predictive of LGA outcomes in pregnancies complicated by diet-managed GDM. This was a retrospective cohort study of singleton pregnancies complicated by diet-managed GDM from 2004 to 2015. Multiple logistic regression analysis was performed on maternal and perinatal factors to identify risk factors for LGA. In addition, a subset univariate analysis was conducted for pregnancies in which fetal ultrasound abdominal circumference measurements were available at gestational weeks 18 to 22, 24 to 28, and 29 to 33. A total of 1064 women were included, delivering 123 LGA infants. Women with higher parity (odds ratio [OR] 1.44; CI, 1.23-1.68; P < .001) and higher prepregnancy body mass index (BMI) (OR 1.09; CI, 1.06-1.12; P < .001) were more likely to have LGA infants. Maternal smoking (OR 0.30; CI, 0.14-0.62; P = .001) and higher gestational age at birth (OR 0.91; CI, 0.84-0.99; P = .018) were associated with reduced risk. Subset univariate analysis showed that fetal abdominal circumference measurements at weeks 24 to 28 and 29 to 33 beyond the 75th percentile (OR 5.92 and 13.74, respectively) and 90th percentile (OR 4.57 and 15.89, respectively) were highly predictive of LGA. Parity, smoking status, maternal BMI, gestational age, and ultrasound fetal abdominal circumference measurements were identified as useful predictors of LGA. Presence of these predictors may prompt closer monitoring of pregnancy and early therapeutic intervention to improve management and reduce the risk of adverse fetal and maternal outcomes.

Impact of biometric measurement error on identification of small- and large-for-gestational-age fetuses.

ABSTRACTObjectivesFirst, to obtain measurement‐error models for biometric measurements of fetal abdominal circumference (AC), head circumference (HC) and femur length (FL), and, second, to examine the impact of biometric measurement error on sonographic estimated fetal weight (EFW) and its effect on the prediction of small‐ (SGA) and large‐ (LGA) for‐gestational‐age fetuses with EFW < 10th and > 90th percentile, respectively.MethodsMeasurement error standard deviations for fetal AC, HC and FL were obtained from a previous large study on fetal biometry utilizing a standardized measurement protocol and both qualitative and quantitative quality‐control monitoring. Typical combinations of AC, HC and FL that gave EFW on the 10th and 90th percentiles were determined. A Monte‐Carlo simulation study was carried out to examine the effect of measurement error on the classification of fetuses as having EFW above or below the 10th and 90th percentiles.ResultsErrors were assumed to follow a Gaussian distribution with a mean of 0 mm and SDs, obtained from a previous well‐conducted study, of 6.93 mm for AC, 5.15 mm for HC and 1.38 mm for FL. Assuming errors according to such distributions, when the 10th and 90th percentiles are used to screen for SGA and LGA fetuses, respectively, the detection rates would be 78.0% at false‐positive rates of 4.7%. If the cut‐offs were relaxed to the 30th and 70th percentiles, the detection rates would increase to 98.2%, but at false‐positive rates of 24.2%. Assuming half of the spread in the error distribution, using the 10th and 90th percentiles to screen for SGA and LGA fetuses, respectively, the detection rates would be 86.6% at false‐positive rates of 2.3%. If the cut‐offs were relaxed to the 15th and 85th percentiles, respectively, the detection rates would increase to 97.0% and the false‐positive rates would increase to 6.3%.ConclusionsMeasurement error in fetal biometry causes substantial error in EFW, resulting in misclassification of SGA and LGA fetuses. The extent to which improvement can be achieved through effective quality assurance remains to be seen but, as a first step, it is important for practitioners to understand how biometric measurement error impacts the prediction of SGA and LGA fetuses. © 2019 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

Accuracy of estimated fetal weight assessment in fetuses with congenital diaphragmatic hernia

Congenital diaphragmatic hernia is a congenital anomaly in which fetal abdominal organs herniate into the thoracic cavity through a diaphragmatic defect, which can impede fetal lung development. Standard formulas for estimated fetal weight include measurement of fetal abdominal circumference, which may be inaccurate in fetuses with congenital diaphragmatic hernia because of displacement of abdominal contents into the thorax. This study aimed to assess the accuracy of standard estimated fetal weight assessment in fetuses with congenital diaphragmatic hernia by comparing prenatal assessment of fetal weight with actual birthweight. A retrospective cohort study of fetuses diagnosed with congenital diaphragmatic hernia was performed at a single center from 2012 to 2018. Fetuses with multiple anomalies or confirmed chromosome abnormalities were excluded. Estimated fetal weight was calculated using the Hadlock formula. Published estimates of fetal growth rate were used to establish a projected estimated fetal weight at birth from the final growth ultrasound, and the percentage difference between projected estimated fetal weight at birth and actual birthweight was calculated. A Wilcoxan rank-sum test was used to examine the difference between projected estimated fetal weight and birthweight. We had complete data for 77 fetuses with congenital diaphragmatic hernia. The majority (76.6%, 55 of 77) had left-sided congenital diaphragmatic hernia. The median [interquartile range] projected estimated fetal weight was similar to median birthweight, at 3177 g [2691-3568] and 3180 g [2630-3500], respectively, which did not represent a statistically significant difference between projected estimated fetal weight and birthweight (P= .66). The median absolute percentage difference between projected birthweight and actual birthweight was 6.3% [3.2-7.0]. Estimated fetal weight was overall underestimated in a minority of cases (44.2%, 34 of 77). In fetuses with a congenital diaphragmatic hernia,standard measurements of fetal estimated fetal weight show accuracy that is at least comparable with previously established margins of error for ultrasound assessment of fetal weight. Standard estimated fetal weight assessment remains an appropriate method ofestimating fetal weight in fetuses with congenital diaphragmatic hernia.

Predictive Value of Fetal Abdominal Circumference in Diagnosing Large for Gestational Age Infants [9D

INTRODUCTION: Macrosomia is associated with adverse perinatal outcomes and has implications for mode of delivery. Research increasingly supports the use of fetal abdominal circumference (AC) as an additional measure to capture large for gestational age (LGA) infants. We evaluated the predictive value of sonographic fetal abdominal circumference (AC) measurement from 25-36 weeks' gestation for detection of LGA infants. METHODS: Retrospective chart review following IRB approval. LGA was defined as a newborn birth weight >90th percentile on the Fenton Growth Curve. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) at various gestational age ranges (25-28, 29-32 and 33-36 weeks' gestation) for a Z-score >+1.88, corresponding to the 97th percentile, were calculated. Area under receiver operating characteristic curve (AUROCC) of AC Z-scores ranging from -3.00 to +3.00 was calculated. RESULTS: Ultrasounds of 4801 women with 5799 pregnancies were reviewed. Our study population had an LGA infant prevalence of 5.8%. An AC Z-score of +1.88 had a maximal sensitivity of 34.3%, specificity of 98.2%, and NPV of 96.2% for detecting LGA births at 29-32 weeks' gestation. The AUROCC at this time point was 0.88. CONCLUSION: Fetal AC <97th percentile in the third trimester has a very high specificity and negative predictive value in ruling out LGA newborns. These measures indicate that this modality can identify pregnancies that are not at high risk for fetal macrosomia and would not benefit from unnecessary cesarean delivery. High AUROCC demonstrates independent predictive potential of AC and supports its adjunct use with more traditional measurements.

869: Can we improve ultrasonographic estimation of fetal weight by reducing operator bias?

To evaluate whether removing real-time display of an estimated gestational age (GA) during third trimester measurement of fetal abdominal circumference (AC) may improve (i) the accuracy of fetal weight estimation (EFW) or (ii) detection of small-for-gestational age (SGA) babies. A prospective interventional study over a 4-year period at a single tertiary UK obstetrics center. In the initial period (Oct 2014-Oct 2017) a standard scan protocol was operated, with real-time information regarding estimated GA displayed. In the intervention period (after Oct 2017) we altered presets on a number of ultrasound machines to withhold estimated GA information from the operator. Other machines were left unchanged as negative controls. The accuracy of EFW and detection rate of SGA (birth weight (BW) <10th centile) were compared before and after the intervention. 18342 deliveries were included, of which 9342 had third-trimester scans. 6432 scans were performed on intervention machines before the switch in scan protocol, and 1178 after. The average discrepancy between EFW centile and actual BW centile was unchanged by the intervention; 3.0 centiles (SD ±21.6) before compared to 2.7 centiles (SD ±20.9) afterwards. The sensitivity for antenatal detection of SGA remained unchanged at 31.5% (CI:27- 36%) before the intervention compared to 31.6% (CI:20-44%) afterwards, with a non-significant increase in the positive likelihood ratio from 18.2 (CI:14.4-23.1) to 19.4 (CI:10.9-35.5). The area under the ROC curve for the detection of SGA using EFW at 36 weeks improved from 0.91 to 0.94, but this difference was not statistically significant (p=0.25, Figure 1), nor was any improvement in detection of SGA using other measured parameters (Table1). Blinding operators to the estimated GA during scanning does not significantly improve concordance between EFW centile and actual BW centile, and does not significantly increase the antenatal detection rate of SGA babies.View Large Image Figure ViewerDownload Hi-res image Download (PPT)