Individualized growth assessment in pregnancies complicated by fetal gastroschisis.

OBJECTIVE: Prenatal ultrasound (US) has been shown to overestimate the incidence of suspected fetal growth restriction (FGR) in gastroschisis cases. This is largely because of altered sonographic abdominal circumference (AC) measurements when comparing gastroschisis cases with population nomograms. Individualized Growth Assessment (IGA) evaluates fetal growth using serial US measurements that allow consideration of the growth potential for a given case. Our goal was to assess the utility of IGA for distinguishing normal and pathological fetal growth in gastroschisis cases. STUDY DESIGN: Pregnancies with prenatally diagnosed fetal gastroschisis were managed and delivered at a single academic medical center. US fetal biometry including head circumference (HC), abdominal circumference (AC), and femur diaphysis length (FDL), and neonatal measurements including birthweight and HC were collected and analyzed for 32 consecutive fetal gastroschisis cases with at least two 2nd and two 3rd trimester measurements. Second trimester growth velocities were compared to a group of 118 non-anomalous fetuses with normal neonatal growth outcomes. Gastroschisis cases were classified into groups based on fetal growth pathology score (FGPS9) patterns. Agreement between IGA (FGPS9) and serial conventional estimated fetal weight (EFW) measurements for determining growth pathology was evaluated. Neonatal size outcomes were compared between conventional birthweight classifications for determining small for gestational age (SGA) and IGA Growth Potential Realization Index (GPRI) for weight and head circumference measurements. RESULTS: Fetal growth pathology score (FGPS9) measurements identified three in-utero growth patterns: no growth pathology, growth restriction and recovery, and progressive growth restriction. In the no growth pathology group (n = 19), there was 84% agreement between IGA and conventional methods in determining pathological growth in both the 3rd trimester and at birth. In the growth restriction and recovery group (n = 7), there was 71% agreement both in the 3rd trimester and at birth between IGA and conventional methods. In the progressive growth restriction group (n = 5), there was 100% agreement in the 3rd trimester and 60% agreement at birth between IGA and conventional methods. CONCLUSION: We present the first study using IGA to evaluate normal and pathological fetal growth in prenatally diagnosed gastroschisis cases. IGA was able to delineate two 3rd trimester growth pathology patterns - one with persistent growth restriction and another with in-utero growth recovery. Further validation of these initial findings with larger cohorts is warranted.

Soft tissue assessment for fetal growth restriction.

Contemporary clinical practice heavily relies on interpretation of population-based birth weight standards to evaluate neonatal nutrition status. Obstetricians have adopted the use of estimated fetal weight in a similar manner to estimate fetal nutritional status. However, most fetal weight prediction models overemphasize skeletal parameters such as biparietal diameter, head circumference, and femur diaphysis length. Although most EFW calculations also include abdominal circumference, this 2D growth parameter is largely defined by liver size and a small rim of subcutaneous fat. Advances in 3D ultrasound imaging and the development of more robust image analysis tools have now made it possible to reliably add a soft tissue component for fetal nutritional assessment. This chapter explains why fetal soft tissue evaluation is clinically relevant, describes different techniques for evaluating these sonographic parameters, and outlines future directions for their practical utility in the care of malnourished fetuses.

Cost-effective fetal lung volumetry for assessment of congenital diaphragmatic hernia.

OBJECTIVES: (1) To investigate the reproducibility of total fetal lung volume (TFLV) measurements using a free 3D modeling software (3DSlicer); (2) To correlate these measurements with lung-to-head ratio (LHR) or TFLV measured using PACS and; (3) To determine the role of 3DSlicer in predicting perinatal outcomes in cases with congenital diaphragmatic hernia (CDH) who had fetal tracheal occlusion (FETO). METHODS: Retrospective cohort study between 2012 and 2017 at Texas Children's Hospital (2011-2017), including all patients who underwent FETO for CDH. LHR was measured by ultrasound and TFLV was measured by MRI at the time of referral and 6 weeks after FETO using 3DSlicer and PACS. We evaluated intra- and inter-rater reliability of TFLV measurement using 3DSlicer, infant survival to 1 year, need for ECMO and pulmonary hypertension. RESULTS: The intra- and inter-rater reliability of TFLV measured with 3DSlicer was excellent before and after FETO (Intra-class correlation coefficient: 0.98-0.99 and 0.94-0.99, respectively). There was a good correlation between TFLV measured with PACS and with 3DSlicer before and after FETO (r = 0.78 and r = 0.99, respectively). Similarly, there was a good correlation between TFLV measurements using PACS or 3DSlicer and LHR after FETO (r = 0.86 and r = 0.88, respectively). Infants who survived to 1 year had a significantly higher TFLV evaluated with 3DSlicer before FETO compared to non-surviving infants (OR = 1.16[1.1-1.3], p = 0.03) as well as a significantly higher TFLV evaluated by 3DSlicer after FETO (OR = 1.2[1-1.4], p = 0.04). CONCLUSION: Lung volume measurements using free 3DSlicer in infants with severe CDH who underwent FETO are reproducible and reliable, and have comparable predictive capability for survival as those measured using conventional software.

Comparison of fetal size standards obtained with conventional methods and individualized assessment: the effect of adjusting for differences in growth potential.

Objective: Detection of fetal growth restriction depends on the biometric standard definitions of normal variability. We examined the impact of correcting for differences in fetal growth potential on the variability of third-trimester size standards.Methods: Size standards, corrected differences in growth potential using Individualized Growth Assessment [IGA], were obtained in 119 pregnancies with normal neonatal growth outcomes. Using the same cohort, a second set of size standards, without these corrections, were determined with mixed modeling [IGA Cross-sectional]. An independent set of size standards, obtained by quantile regression in a population-based sample of 1387 pregnant women [World Health Organization (WHO)], was also evaluated. The anatomical parameters studied included BPD, HC, AC, FDL, THC, HDL, ArmC and EWT whenever possible. The variability measures compared were percent deviation reference range [IGA] or twice the coefficient of variation [IGA Cross-sectional, WHO] at weekly time points between 28 and 38 weeks, menstrual age.Results: All six IGA variabilities were significantly smaller [range: 19-60%] when IGA and IGA-cross-sectional size standards were compared. Similar IGA-WHO comparisons showed that the IGA variabilities for 5 of 6 anatomical parameters were significantly smaller [range: 26-32%; exception: FDL (5.8%)]. Comparisons of cross-sectional size standards gave variable results depending on the anatomical parameter studied.Conclusions: Third-trimester variability measures, based on IGA, were consistently lower than those obtained with conventional cross-sectional methods in normal pregnancies. These results were found when the identical sample was used in both IGA and cross-sectional analyses. Decreased variability can improve the sensitivity of IGA for detecting restricted growth and may be partly responsible for its ability to identify different types of growth abnormalities earlier in pregnancy.

Second trimester growth velocities: assessment of fetal growth potential in SGA singletons.

OBJECTIVE: To evaluate the validity of second trimester growth velocities as measures of fetal growth potential in Small-for-Gestational-Age (SGA) singletons. METHODS: Second trimester growth velocities for biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur diaphysis length (FDL) were determined by linear regression analysis or direct measurement in 53 SGA singletons with normal growth outcomes (SGA N Group) and 73 with growth restriction (SGA GR) based on a composite fetal growth pathology score (FGPS1). The latter were subdivided into six groups based on their growth restriction pattern (Patterns group). Similar data were available for 118 singletons with normal neonatal growth outcomes (NNGO group). Coefficients of determination (R2) and growth velocities for each anatomical parameter were compared between Patterns subgroups and the SGA N, SGA GR and NNGO groups. RESULTS: Median R2 values in the six Patterns subgroups ranged from 98.2% (Pattern 2, FDL) to 99.9% (Pattern 5, AC). Within each anatomical parameter set, no significant differences were found (Kruskal-Wallis). Patterns subgroup data were pooled to form the SGA GR group for each anatomical parameter. Mean values for the three main groups ranged from 98.4% (SGA N, FDL) to 99.6% (SGA N, HC). No significant differences between groups (ANOVA) were found for any anatomical parameter (ANOVA). Only 1.7-3.8% had R2 values <95th%. No significant differences in median second trimester growth velocities among different Patterns subgroups were found for any anatomical parameter. In the SGA N and SGA GR groups, mean BPD and HC values did not differ but were significantly smaller than the NNGO group values. No differences in mean FDL values were seen. With AC, all three means were significantly different, having the following order: NNGO > SGA N > SGA GR. Of all 504 second trimester growth rates, 92.5% were within their respective 95% reference ranges. CONCLUSION: Growth in the second trimester is linear in fetuses at risk for growth restriction. Except for FDL, growth velocities were lower than those for fetuses with NNGO. Only AC had mean velocities that differed between the SGA N and the SGA GR groups. Since most velocities (92.5%) were within normal reference ranges, they are reasonable measures of growth potential in fetuses at risk for growth restriction.

Individualized growth assessment: conceptual framework and practical implementation for the evaluation of fetal growth and neonatal growth outcome.

Fetal growth abnormalities can pose significant consequences on perinatal morbidity and mortality of nonanomalous fetuses. The most widely accepted definition of fetal growth restriction is an estimated fetal weight less than the 10th percentile for gestational age according to population-based criteria. However, these criteria do not account for the growth potential of an individual fetus, nor do they effectively separate constitutionally small fetuses from ones that are malnourished. Furthermore, conventional approaches typically evaluate estimated fetal weight at a single time point, rather than using serial scans, to evaluate growth. This article provides a conceptual framework for the individualized growth assessment of a fetus/neonate based on measuring second-trimester growth velocity of fetal size parameters to estimate growth potential. These estimates specify size models that generate individualized third-trimester size trajectories and predict birth characteristics. Comparisons of measured and predicted values are used to separate normally growing fetuses from those with growth abnormalities. This can be accomplished with individual anatomical parameters or sets of parameters. A practical and freely available software (Individualized Growth Assessment Program) has been developed to allow implementation of this approach for clinical and research purposes.

Obstetric and gynecologic ultrasound curriculum and competency assessment in residency training programs: consensus report.

Ultrasound imaging has become integral to the practice of obstetrics and gynecology. With increasing educational demands and limited hours in residency programs, dedicated time for training and achieving competency in ultrasound has diminished substantially. The American Institute of Ultrasound in Medicine assembled a multisociety task force to develop a consensus-based, standardized curriculum and competency assessment tools for obstetric and gynecologic ultrasound training in residency programs. The curriculum and competency assessment tools were developed based on existing national and international guidelines for the performance of obstetric and gynecologic ultrasound examinations and thus are intended to represent the minimum requirement for such training. By expert consensus, the curriculum was developed for each year of training, criteria for each competency assessment image were generated, the pass score was established at, or close to, 75% for each, and obtaining a set of 5 ultrasound images with pass score in each was deemed necessary for attaining each competency. Given the current lack of substantial data on competency assessment in ultrasound training, the task force expects that the criteria set forth in this document will evolve with time. The task force also encourages use of ultrasound simulation in residency training and expects that simulation will play a significant part in the curriculum and the competency assessment process. Incorporating this training curriculum and the competency assessment tools may promote consistency in training and competency assessment, thus enhancing the performance and diagnostic accuracy of ultrasound examination in obstetrics and gynecology.

Obstetric and Gynecologic Ultrasound Curriculum and Competency Assessment in Residency Training Programs: Consensus Report.

Ultrasound imaging has become integral to the practice of obstetrics and gynecology. With increasing educational demands and limited hours in residency programs, dedicated time for training and achieving competency in ultrasound has diminished substantially. The American Institute of Ultrasound in Medicine assembled a multisociety task force to develop a consensus-based, standardized curriculum and competency assessment tools for obstetric and gynecologic ultrasound training in residency programs. The curriculum and competency assessment tools were developed based on existing national and international guidelines for the performance of obstetric and gynecologic ultrasound examinations and thus are intended to represent the minimum requirement for such training. By expert consensus, the curriculum was developed for each year of training, criteria for each competency assessment image were generated, the pass score was established at, or close to, 75% for each, and obtaining a set of 5 ultrasound images with pass score in each was deemed necessary for attaining each competency. Given the current lack of substantial data on competency assessment in ultrasound training, the task force expects that the criteria set forth in this document will evolve with time. The task force also encourages use of ultrasound simulation in residency training and expects that simulation will play a significant part in the curriculum and the competency assessment process. Incorporating this training curriculum and the competency assessment tools may promote consistency in training and competency assessment, thus enhancing the performance and diagnostic accuracy of ultrasound examination in obstetrics and gynecology.

Clinical assessment and brain findings in a cohort of mothers, fetuses and infants infected with ZIKA virus.

BACKGROUND: Congenital Zika virus (ZIKV) infection can be detected in both the presence and absence of microcephaly and manifests as a number of signs and symptoms that are detected clinically and by neuroimaging. However, to date, qualitative and quantitative measures for the purpose of diagnosis and prognosis are limited. OBJECTIVES: Main objectives of this study conducted on fetuses and infants with confirmed congenital Zika virus infection and detected brain abnormalities were (1) to assess the prevalence of microcephaly and the frequency of the anomalies that include a detailed description based on ultrasound and magnetic resonance imaging in fetuses and ultrasound, magnetic resonance imaging, and computed tomography imaging postnatally, (2) to provide quantitative measures of fetal and infant brain findings by magnetic resonance imaging with the use of volumetric analyses and diffusion-weighted imaging, and (3) to obtain additional information from placental and fetal histopathologic assessments and postnatal clinical evaluations. STUDY DESIGN: This is a longitudinal cohort study of Zika virus-infected pregnancies from a single institution in Colombia. Clinical and imaging findings of patients with laboratory-confirmed Zika virus infection and fetal brain anomalies were the focus of this study. Patients underwent monthly fetal ultrasound scans, neurosonography, and a fetal magnetic resonance imaging. Postnatally, infant brain assessment was offered by the use of ultrasound imaging, magnetic resonance imaging, and/or computed tomography. Fetal head circumference measurements were compared with different reference ranges with <2 or <3 standard deviations below the mean for the diagnosis of microcephaly. Fetal and infant magnetic resonance imaging images were processed to obtain a quantitative brain volumetric assessment. Diffusion weighted imaging sequences were processed to assess brain microstructure. Anthropometric, neurologic, auditory, and visual assessments were performed postnatally. Histopathologic assessment was included if patients opted for pregnancy termination. RESULTS: All women (n=214) had been referred for Zika virus symptoms during pregnancy that affected themselves or their partners or if fetal anomalies that are compatible with congenital Zika virus syndrome were detected. A total of 12 pregnant patients with laboratory confirmation of Zika virus infection were diagnosed with fetal brain malformations. Most common findings that were assessed by prenatal and postnatal imaging were brain volume loss (92%), calcifications (92%), callosal anomalies (100%), cortical malformations (89%), and ventriculomegaly (92%). Results from fetal brain volumetric assessment by magnetic resonance imaging showed that 1 of the most common findings associated with microcephaly was reduced supratentorial brain parenchyma and increased subarachnoid cerebrospinal fluid. Diffusion weighted imaging analyses of apparent diffusion coefficient values showed microstructural changes. Microcephaly was present in 33.3-58.3% of the cases at referral and was present at delivery in 55.6-77.8% of cases. At birth, most of the affected neonates (55.6-77.8%) had head circumference measurements >3 standard deviations below the mean. Postnatal imaging studies confirmed brain malformations that were detected prenatally. Auditory screening results were normal in 2 cases that were assessed. Visual screening showed different anomalies in 2 of the 3 cases that were examined. Pathologic results that were obtained from 2 of the 3 cases who opted for termination showed similar signs of abnormalities in the central nervous system and placental analyses, including brain microcalcifications. CONCLUSION: Congenital microcephaly is not an optimal screening method for congenital Zika virus syndrome, because it may not accompany other evident and preceding brain findings; microcephaly could be an endpoint of the disease that results from progressive changes that are related to brain volume loss. Long-term studies are needed to understand the clinical and developmental relevance of these findings.

Third trimester growth restriction patterns: individualized assessment using a fetal growth pathology score.

OBJECTIVE: To qualitatively and quantitatively characterize third trimester growth patterns in fetuses/neonates with growth restriction using Individualized Growth Assessment. METHODS: Serial fetal size measurements from 73 fetuses with proven growth restriction were evaluated using a novel composite parameter, the Fetal Growth Pathology Score (FGPS1). Third trimester FGPS1 measurements plotted against fetal age were examined for patterns. Identified patterns were characterized using the four components of the FGP1 [head circumference (HC), abdominal circumference (AC), femur diaphysis length (FDL), estimated weight (EWT)]. A secondary characterization using age of onset, duration and magnitude of the growth abnormality process was also performed. Frequencies and magnitudes of abnormal values in different FGPS1 patterns were compared. RESULTS: Five growth restriction patterns were found in 70/73 (95.9%) of the cases, with progressive worsening [Pattern 1 (37.0%)] and abnormal growth identified only at last scan [Pattern 2 (27.4%)] being the most common. These two patterns were usually statistically different from each other and the other three with respect to size parameter abnormalities and abnormal growth process characteristics (MANOVA). Growth abnormalities in all parameters of the FGPS1 contributed to the five abnormality patterns although AC and EWT were most important. The age of onset, duration and magnitude were similar between patterns except for Pattern 2, which had a late onset and a short duration (GLM + contrasts). CONCLUSIONS: Our study represents the first detailed evaluation of third trimester growth restriction using methods that consider the growth potential of each fetus. Five distinctive and repetitive patterns were found, suggesting that fetal growth restriction evolves in different ways. Further research is needed to determine the relationships of these patterns to physiological/biochemical changes and adverse outcomes associated with growth restriction.

Fetal growth pathology score: a novel ultrasound parameter for individualized assessment of third trimester growth abnormalities.

OBJECTIVES: To study fetal growth in pregnancies at risk for growth restriction (GR) using, for the first time, the fetal growth pathology score (FGPS1). METHODS: A retrospective cohort study of GR was carried out in 184 selected SGA singletons using a novel, composite measure of growth abnormalities termed the FGPS1. Serial fetal biometry was used to establish second trimester Rossavik size models and determine FGPS1 values prior to delivery. FGPS1 data were compared to neonatal growth outcomes assessed using growth potential realization index (GPRI) values (average negative pathological GPRI (av - pGPRI)). Growth at the end of pregnancy was evaluated from differences in negative, individual composite prenatal growth assessment scores (-icPGAS) measured at the last two ultrasound scans. The FGPS1 and av - pGPRI values were used to classify fetal growth and neonatal growth outcomes, respectively, as Normal (N) or Abnormal (A). RESULTS: The risk of neonatal GR (based on birth weight (BW)) was moderate (MR: between 5th and10th percentiles (n = 113)) or significant (SR:<5th percentile) (n = 71)). Individual pregnancies were grouped into four categories, two representing agreement (N-N (29%), A-A (40%)) and two representing discordance (N-A (11%), A-N (20%)). In the largest and most variable subgroup (A-A,<5%tile, n = 49), there was a statistically significant correlation (0.63, p < .0001) between the FGPS1 and av - pGPRI. In N-A, all 20 cases (100%) had long last-scan-to-delivery intervals (1.9 weeks or greater), suggesting late development of the growth abnormality. For A-N, in approximately equal proportions, GR was improving, progressing or unclassifiable at the end of pregnancy. CONCLUSIONS: Significant agreement between prenatal and postnatal growth assessments was found using a novel approach for quantifying fetal growth pathology (FGPS1). Discordances appear to be due to lack of appropriate prenatal scans or an inadequate set of neonatal measurements. Evidence for a quantitative relationship between assessment methods was seen in the largest and most variable subgroup. The FGPS1 has the potential for characterizing GR in the third trimester and may provide a means for predicting the severity of corresponding abnormal neonatal growth outcomes.

A Novel Semiautomated Fractional Limb Volume Tool for Rapid and Reproducible Fetal Soft Tissue Assessment.

The purpose of this study was to document the reproducibility and efficiency of a semiautomated image analysis tool that rapidly provides fetal fractional limb volume measurements. Fifty pregnant women underwent 3-dimensional sonographic examinations for fractional arm and thigh volumes at a mean menstrual age of 31.3 weeks. Manual and semiautomated fractional limb volume measurements were calculated, with the semiautomated measurements calculated by novel software (5D Limb Vol; Samsung Medison, Seoul, Korea). The software applies an image transformation method based on the major axis length, minor axis length, and limb center coordinates. A transformed image is used to perform a global optimization technique for determination of an optimal limb soft tissue boundary. Bland-Altman analysis defined bias with 95% limits of agreement (LOA) between methods, and timing differences between manual versus automated methods were compared by a paired t test. Bland-Altman analysis indicated an acceptable bias with 95% LOA between the manual and semiautomated methods: mean arm volume ± SD, 1.7% ± 4.6% (95% LOA, -7.3% to 10.7%); and mean thigh volume, 0.0% ± 3.8% (95% LOA, -7.5% to 7.5%). The computer-assisted software completed measurements about 5 times faster compared to manual tracings. In conclusion, semiautomated fractional limb volume measurements are significantly faster to calculate when compared to a manual procedure. These results are reproducible and are likely to reduce operator dependency. The addition of computer-assisted fractional limb volume to standard biometry may improve the precision of estimated fetal weight by adding a soft tissue component to the weight estimation process.

Improving the Prediction of Neonatal Outcomes in Isolated Left-Sided Congenital Diaphragmatic Hernia by Direct and Indirect Sonographic Assessment of Liver Herniation.

OBJECTIVES: Liver herniation can be assessed sonographically by either a direct (liver-to-thoracic area ratio) or an indirect (stomach position) method. Our objective was to evaluate the utility of those methods to assess liver herniation for the prediction of neonatal outcomes in patients with isolated left-sided congenital diaphragmatic hernia (CDH). METHODS: We conducted a retrospective cohort study of all patients with CDH who had prenatal assessment and were delivered at Texas Children's Hospital between January 2004 and April 2014. The predictive value of sonographic parameters for mortality and the need for extracorporeal membrane oxygenation was evaluated by univariate, multivariate, and factor analysis and by receiver operating characteristics curves. RESULTS: A total of 77 fetuses with isolated left-sided CDH were analyzed. The lung-to-head ratio, liver-to-thorax ratio, and stomach position (according to the classifications of Kitano et al [Ultrasound Obstet Gynecol 2011; 37:277-282] and Cordier et al [J Matern Fetal Neonatal Med 2015; 28:190-195]) were significantly associated with both neonatal outcomes (P < .03). Significant correlations were observed between all of these sonographic parameters. A combination of the liver-to-thorax ratio and stomach position (Kitano) or stomach position (Cordier) with the lung-to-head ratio increased the area under the receiver operating characteristic curve of the lung-to-head ratio for mortality prediction (0.86 [95% confidence interval, 0.74-0.98], 0.83 [0.72-0.95], and 0.83 [0.74-0.92], respectively). CONCLUSIONS: Sonographic measurements of liver herniation (liver-to-thorax ratio and stomach position) are predictive of neonatal outcomes in isolated left-sided congenital diaphragmatic hernia. Our study shows that the combination of those sonographic measurements of liver herniation and lung size improves the accuracy of predicting mortality in those fetuses.

Classifying neonatal growth outcomes: use of birth weight, placental evaluation and individualized growth assessment.

OBJECTIVE: To compare neonatal growth outcomes determined by birth weight (BW), placental assessment (Plac Assess) and individualized growth assessment (IGA). METHODS: This retrospective analysis was carried out in 45 selected pregnancies at risk for fetal growth restriction. Serial fetal biometry was carried out in the 2nd and 3rd trimester. First and second trimester placental biomarkers, 2nd trimester uterine artery (Ut A) velocimetry and postnatal placental pathology were evaluated as indicators of placental insufficiency. At delivery, weight (WT), head circumference (HC) and crown-heel length (CHL) were measured. BWs were categorized as large-for-gestational-age (LGA), appropriate-for-gestational-age (AGA) and small-for-gestational age (SGA) (<10th, 10th-90th and >90th percentiles). In these categories, neonatal growth outcomes were classified as growth restricted (GR), normal (NORMAL) or macrosomic (MACRO) based on BW plus Plac Assess (Ut A velocimetry, biomarkers, pathology) or IGA [growth potential realization index profile (WT, HC and CHL)]. RESULTS: There were 6 LGA, 14 AGA and 25 SGA neonates in this sample. All 14 AGA neonates were considered NORMAL by both IGA and BW + Plac Assess. All six LGA neonates were classified as MACRO by BW + Plac Assess but only four by IGA (the remaining two were NORMAL and high NORMAL). The 25 SGA cases could be divided into five subgroups based on IGA and BW + Plac Assess. The largest subgroup (56%) was GR and the next largest (24%) was NORMAL by both classification methods. In the remaining 20%, there was some evidence of GR but IGA and BW + Plac Assess were not in complete agreement. CONCLUSIONS: Agreement was good for all three methods in the LGA and AGA groups. The SGA group was heterogeneous but agreement between IGA and BW + Plac Assess was 89%. These results, using more sophisticated growth assessment methods, confirm placental insufficiency as a primary cause of growth restriction. Most normal and GR SGA neonates can be identified with conventional anatomical measurements if IGA is used.

Personalized third-trimester fetal growth evaluation: comparisons of individualized growth assessment, percentile line and conditional probability methods.

OBJECTIVE: To compare third-trimester size trajectory prediction errors (average transformed percent deviations) for three individualized fetal growth assessment methods. METHODS: This study utilized longitudinal measurements of nine directly measured size parameters in 118 fetuses with normal neonatal growth outcomes. Expected value (EV) function coefficients and variance components were obtained using two-level random coefficient modeling. Growth models (IGA) or EV coefficients and variance components (PLM and CPM) were used to calculate predicted values at ∼400 third-trimester time points. Percent deviations (%Dev) calculated at these time points using all three methods were expressed as percentages of IGA MA-specific reference ranges [transformed percent deviations (T%Dev)]. Third-trimester T%Dev values were averaged (aT%Dev) for each parameter. Mean ± standard deviation's for sets of aT%Dev values derived from each method (IGA, PLM and CPM) were calculated and compared. RESULTS: Mean aT%Dev values for nine parameters were: (i) IGA: -4.3 to 5.2% (9/9 not different from zero); (ii) PLM: -32.7 to 25.6% (4/9 not different from zero) and (iii) CPM: -20.4 to 17.4% (5/9 not different from zero). Seven of nine systematic deviations from zero were statistically significant when IGA values were compared to either PLM or CPM values. Variabilities were smaller for IGA when compared to those for PLM or CPM, with (i) 5/9 being statistically significant (IGA versus PLM), (ii) 2/9 being statistically significant (IGA versus CPM) and (iii) 5/9 being statistically significant (PLM versus CPM). CONCLUSIONS: Significant differences in the agreement between predicted third-trimester size parameters and their measured values were found for the three methods tested. With most parameters, IGA gave smaller mean aT%Dev values and smaller variabilities. The CPM method was better than the PLM approach for most but not all parameters. These results suggest that third-trimester size trajectories are best characterized by IGA in fetuses with normal growth outcomes.

A modified prenatal growth assessment score for the evaluation of fetal growth in the third trimester using single and composite biometric parameters.

OBJECTIVE: To define modified Prenatal Growth Assessment Scores (mPGAS) for single and composite biometric parameters and determine their reference ranges in normal fetuses. METHODS: Nine anatomical parameters (ap) were measured and the weight estimated (EWTa, EWTb) in a longitudinal study of 119 fetuses with normal neonatal growth outcomes. Expected third trimester size trajectories, obtained from second trimester Rossavik size models, were used in calculating Percent Deviations (% Dev's) and their age-specific reference ranges in each fetus. The components of individual % Dev's values outside their reference ranges, designated +iapPGAS, -iapPGAS, were averaged to give +apPGAS and -apPGAS values for the 3rd trimester. The +iapPGAS and -iapPGAS values for different combinations of ap (c1a (HC, AC, FDL, ThC, EWTa), c1b (HC, AC, FDL, ThC, EWTb), c2 (ThC, ArmC, AVol, TVol), c3 (HC, AC, FDL, EWTa)) were then averaged to give +icPGAS and -icPGAS values at different time points or at the end of the third trimester (+cPGAS, -cPGAS). Values for iapPGAS, ic1bPGAS, and ic2PGAS were compared to their respective apPGAS or cPGAS reference ranges. RESULTS: All mPGAS values had one 95% range boundary at 0.0%. Upper boundaries of 1D +apPGAS values ranged from 0.0% (HC) to +0.49% (ThC) and were +0.06%, +2.3% and +1.8% for EWT, AVol and TVol, respectively. Comparable values for -apPGAS were 0.0% (BPD, FDL, HDL), to -0.58% (ArmC), -0.13% (EWT), -0.8% (AVol), and 0.0% (TVol). The +cPGAS, 95% reference range upper boundaries varied from +0.36% (c1b) to +0.89% (c2). Comparable values for -cPGAS lower boundaries were -0.17% (c1b) to -0.43% (c2). CONCLUSIONS: The original PGAS concept has now been extended to individual biometric parameters and their combinations. With the standards provided, mPGAS values can now be tested to see if detection of different types of third trimester growth problems is improved.

Individualized fetal growth assessment: critical evaluation of key concepts in the specification of third trimester size trajectories.

OBJECTIVES: To characterize second and third trimester fetal growth using Individualized Growth Assessment methods in a larger cohort of fetuses with normal neonatal growth outcomes. METHODS: A prospective longitudinal study of 119 pregnancies was performed from 18 weeks, MA, to delivery. Measurements of several 1D and 3D fetal size parameters were obtained from 3D volume data sets at 3-4 week intervals. Regression analyses were used to determine Start Points (SP) and Rossavik model (P = c {t} (k + st)) coefficients c. k and s for each parameter in each fetus. Second trimester growth velocity reference ranges were determined and size model specification functions re-established, the latter used to generate individual size models. Actual measurements were compared to predicted third trimester size trajectories using Percent Deviations. New age-specific reference ranges for the Percent Deviations of each parameter were defined using 2-level statistical modeling. RESULTS: Rossavik models fit the data for all parameters very well (R(2): 99%), with SP's and k values similar to those found in much smaller cohorts. The c* values were strongly related to the second trimester slope (R(2): 97%), as was predicted s* to estimated c* (R(2): 54--95%). Rossavik models predicted third trimester growth with systematic errors close to 0%; random errors (95% range) ranged between 5.7 and 10.9% and 20.0 and 24.3% for 1D and 3D parameters, respectively. CONCLUSIONS: IGA procedures for evaluating second and third trimester growth are now established based on a larger cohort (4-6 fold larger). New, more rigorously defined, age-specific standards for the evaluation of third trimester size deviations are now available for nine anatomical parameters and a weight estimation procedure that incorporates a soft tissue parameter (fractional thigh volume). These results provide a means for more reliably assessing fetal growth on an individualized basis, thus minimizing the effect of biological differences in growth.

Three-dimensional ultrasonographic assessment of fetal total lung volume as a prognostic factor in primary pleural effusion.

OBJECTIVES: The purpose of this study was to predict perinatal outcomes using fetal total lung volumes assessed by 3-dimensional ultrasonography (3DUS) in primary pleural effusion. METHODS: Between July 2005 and July 2010, total lung volumes were prospectively estimated in fetuses with primary pleural effusion by 3DUS using virtual organ computer-aided analysis software. The first and last US examinations were considered in the analysis. The observed/expected total lung volumes were calculated. Main outcomes were perinatal death (up to 28 days of life) and respiratory morbidity (orotracheal intubation with mechanical respiratory support >48 hours). RESULTS: Twelve of 19 fetuses (63.2%) survived. Among the survivors, 7 (58.3%) had severe respiratory morbidity. The observed/expected total lung volume at the last US examination before birth was significantly associated with perinatal death (P < .01) and respiratory morbidity (P < .01) as well as fetal hydrops (P < .01) and bilateral effusion (P = .01). CONCLUSIONS: Fetal total lung volumes may be useful for the prediction of perinatal outcomes in primary pleural effusion.