ISUOG Practice Guidelines (updated): performance of the routine mid-trimester fetal ultrasound scan

Validation of an automatic software in assessing fetal brain volume from three dimensional ultrasonographic volumes: Comparison with manual analysis

OBJECTIVE

This study was aimed to test the agreement between a manual and an automatic technique in measuring fetal brain volume (FBV) from three-dimensional (3D) fetal head datasets.

METHODS

FBV were acquired independently by two operators from low risk singleton pregnancies at a gestational age between 19 and 34 weeks. FBV measurements were obtained using an automatic software (Smart ICV™) and manually by Virtual Organ Computer-aided AnaLysis (VOCAL™). Intraclass correlation coefficient (ICC) were calculated to assess reliability, while bias and agreement were evaluate by examining Bland-Altman plots. The time spent in measuring volumes was calculated and values obtained compared.

RESULTS

Sixty-three volumes were considered for the study. In all the included volumes successful volume analysis were obtained with both techniques. Smart ICV™ showed a high intra-observer (0.996; 95% CI 0.994-0.998) and inter-observer (ICC 0.995; 95% CI 0.991-0.997). An excellent degree of reliability was found when the two techniques were compared (ICC 0.995; 95% CI 0.987-0.998). The time required to perform FBV was significantly lower for Smart ICV™ than VOCAL™ (8.2 ± 4.5 vs. 121.3 ± 19.0 s; p < 0.0001).

CONCLUSIONS

The measurement of FBV is feasible with both manual and automatic techniques. Smart ICV™ showed an excellent intra- and inter-observer reliability associated with a valuable agreement with volume measurements obtained manually with VOCAL™. Volumes may be measured significantly faster with smart ICV™ than manually and this automatic software has the potential to become the preferred methods for the assessment of FBV.

Prenatal diagnosis of cleft lip and/or palate: What do we tell prospective parents?

Cleft lip and/or palate (CL/CP) is the most common congenital craniofacial anomaly and parents often ask, "how did this happen?" Patients and families may benefit from access to a multidisciplinary team (MDT) from prenatal diagnosis into early adulthood. Multiple factors can contribute to the development of a cleft. We discuss the epidemiology and risk factors that increase the likelihood of having a newborn with a cleft. The purpose of this article is to review the prenatal investigations involved in the diagnosis and workup of these patients in addition to postpartum treatment, prognostic factors, and counseling families regarding future recurrence risk.

Automatic Deep Learning-Based Pipeline for Automatic Delineation and Measurement of Fetal Brain Structures in Routine Mid-Trimester Ultrasound Images

INTRODUCTION

The aim of this study was to develop a pipeline using state-of-the-art deep learning methods to automatically delineate and measure several of the most important brain structures in fetal brain ultrasound (US) images.

METHODS

The dataset was composed of 5,331 images of the fetal brain acquired during the routine mid-trimester US scan. Our proposed pipeline automatically performs the following three steps: brain plane classification (transventricular, transthalamic, or transcerebellar plane); brain structures delineation (9 different structures); and automatic measurement (from the structure delineations). The methods were trained on a subset of 4,331 images and each step was evaluated on the remaining 1,000 images.

RESULTS

Plane classification reached 98.6% average class accuracy. Brain structure delineation obtained an average pixel accuracy higher than 96% and a Jaccard index higher than 70%. Automatic measurements get an absolute error below 3.5% for the four standard head biometries (head circumference, biparietal diameter, occipitofrontal diameter, and cephalic index), 9% for transcerebellar diameter, 12% for cavum septi pellucidi ratio, and 26% for Sylvian fissure operculization degree.

CONCLUSIONS

The proposed pipeline shows the potential of deep learning methods to delineate fetal head and brain structures and obtain automatic measures of each anatomical standard plane acquired during routine fetal US examination.

Use of artificial intelligence and deep learning in fetal ultrasound imaging

Deep learning is considered the leading artificial intelligence tool in image analysis in general. Deep-learning algorithms excel at image recognition, which makes them valuable in medical imaging. Obstetric ultrasound has become the gold standard imaging modality for detection and diagnosis of fetal malformations. However, ultrasound relies heavily on the operator's experience, making it unreliable in inexperienced hands. Several studies have proposed the use of deep-learning models as a tool to support sonographers, in an attempt to overcome these problems inherent to ultrasound. Deep learning has many clinical applications in the field of fetal imaging, including identification of normal and abnormal fetal anatomy and measurement of fetal biometry. In this Review, we provide a comprehensive explanation of the fundamentals of deep learning in fetal imaging, with particular focus on its clinical applicability. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Current practice of placental cord insertion documentation in Australia - A sonographer survey

Introduction

During pregnancy, the umbilical cord attaches to the placenta in a central, eccentric, marginal or velamentous location. Maternal and fetal complications are associated with marginal and velamentous cord insertions, the most clinically significant being perinatal mortality due to undiagnosed vasa praevia. Current literature describes a wide variation regarding regulation of placental cord insertion (PCI) documentation during antenatal ultrasound examinations. This prospective cross-sectional study aimed to assess the current practice of antenatal PCI documentation in Australia.

Methods

Members of the Australian Sonographer Accreditation Registry were invited to participate in an online survey which was distributed between February and March 2022.

Results

Four hundred ninety sonographers met the inclusion criteria for the study of which 330 (67.3%) have more than 10 years' experience as a sonographer and 375 (76.5%) are employed primarily in a public or private setting offering general ultrasound. Most respondents (89.6%) indicated documentation of the PCI site is departmental protocol at the second trimester anatomy scan (17-22 weeks gestation), but PCI documentation is protocol in less than 50% of other obstetric ultrasound examinations listed in the survey. The PCI site is included in the formal ultrasound report at a rate significantly less than inclusion in the departmental protocol and the sonographer's worksheet.

Conclusions

Considering the potential maternal and fetal complications associated with abnormal PCI and the ease at which the PCI site is identified in the first and second trimesters, we believe that standard inclusion of the PCI site in departmental protocol and in the formal ultrasound report from 11 weeks gestation, regardless of whether it is normal or abnormal, would prove invaluable.

Exploring the Role of Modified Vascular Anatomical Molding (MVAM) in Prenatal Diagnosis Teaching and Prognosis Prediction of Fetal Complex Congenital Heart Disease (CCHD): A Preliminary Study

Objective

The present study aimed to explore the role of modified vascular anatomical molding (MVAM) in prenatal diagnosis teaching and prognosis prediction of fetal complex congenital heart disease (CCHD).

Methods

Step 1, MVAM method was used to cast the micro-blood vessels and trachea of 52 CCHD specimens. Subsequently, 52 MVAMs were analyzed and compared with the prenatal ultrasound to summarize their characteristics, misdiagnosis and MVAM's teaching role. Step 2, the surgical and follow-up data of 206 CCHD cases were retrospectively analyzed. Cases that evolved into critical illnesses or died within 1-3 years after surgery (poor prognosis) were classified into the study group (n = 77) and those with good prognosis into the control group (n = 129), which were split into the training set and the test set in the ratio 7:3 based on the time cut-off. In the training set, the prognosis of CCHD was predicted using the MVAM anatomical soft markers (distortion and narrowing of aorta/pulmonary artery, right ventricular infundibulum, etc.) and the decision curve analysis (DCA) performed. The model was validated using the test set, and a nomogram was finally established.

Results

It was observed that all 52 CCHD cases were confirmed using MVAM. A total of 91 cardiac malformations were recorded, among which 41 malformations were misdiagnosed, and 29 malformations were missed by the prenatal echocardiography. The MVAM method has a good teaching/feedback effect on prenatal diagnosis. The combined model exhibited a higher predictive performance in the training- and test-set. Its high clinical net benefit was proved by DCA. Additionally, the nomogram established using the combined model received a favorable response in clinical practice.

Conclusion

The research results indicated that MVAM improved the prenatal diagnosis teaching and training performance. The combined model established based on MVAM anatomical soft markers can offer a high clinical significance for prognosis prediction of CCHD.

Cleft Lip and Palate Antenatal Diagnosis: A Swiss University Center Performance Analysis

Precision of cleft lip and/or palate antenatal diagnosis plays a significant role in counselling, neonatal care, surgical strategies and psychological support of the family. This study aims to measure the accuracy of antenatal diagnosis in our institution and the detection rate of cleft lip and/or palate on routine morphologic ultrasonography. In this retrospective observational study, we compared antenatal and postnatal diagnosis of 233 patients followed in our unit. We classified our patients according to the Kernahan and Stark's classification system: Group 1: facial cleft including labial and labio-maxillary clefts; Group 2: facial cleft including total, subtotal and submucous palatal clefts; Group 3: labio-maxillary-palatal clefts. Out of 233 patients, 104 were antenatally diagnosed with a facial cleft, i.e., an overall detection rate of 44.6%. The diagnosis was confirmed at birth in 65 of these patients, i.e., an overall accuracy of 62.5%. Of the 67 children (29.2%) in Group 1, the screening detection rate was 58.2% with an antenatal diagnostic accuracy of 48.7%. Of the 97 children (41.6%) in Group 2, the screening detection rate was 2% with an antenatal diagnostic accuracy of 50%. Of the 69 children (29.6%) in Group 3, the screening detection rate was 91.3% with an antenatal diagnostic accuracy of 71.4%. Our study demonstrates a relatively poor diagnostic accuracy in prenatal ultrasound, where the diagnosis was inaccurate in one third to one half of patients. It showed great variability in the screening detection rate depending on the diagnostic group observed, as well as a low rate of detection of palatal clefts.

Childhood Outcomes in Children with and without Cardiac Echogenic Foci: An Electronic Birth Cohort Study in Wales, UK

There is uncertainty about outcomes associated with cardiac echogenic foci (CEF) seen at the midtrimester ultrasound scan because of limited population-based follow-up data. This can lead to unnecessary invasive testing and significant parental anxiety. We analysed data from a cohort study, The Welsh Study of Mothers and Babies, to examine whether children with CEF had more adverse outcomes during childhood compared with children without CEF. Children born between 1 January 2009 and 31 December 2011 were followed until 31 January 2018, migration out of Wales, or death. The primary outcome was cardiac hospital admissions, defined a priori by an expert steering group. Secondary outcomes included congenital cardiac anomalies, and hospital admissions for other causes. There was no evidence of an association between isolated CEF and cardiac hospital admissions (hazard ratio 0.87, 95% confidence interval [CI] 0.33-2.25, p value 0.768), or with congenital cardiac anomalies. There was a small increased risk of a respiratory admission with isolated CEF (hazard ratio 1.27, 95% CI 1.04-1.54, p value 0.020). Further research is needed on features of CEF, such as location or number, to fully understand the clinical significance of these findings.

Cleft palate in fetuses: feasibility of early diagnosis by Crystal and Realistic Vue rendering 3D ultrasound technology in the first trimester

Objectives

This study aimed to evaluate the feasibility of direct visualization of a normal fetal palate and detect cleft palate in the first trimester with a novel three-dimensional ultrasound (3D US) technique, Crystal and Realistic Vue (CRV) rendering technology.

Methods

Two-dimensional (2D) images and 3D volumes of healthy and cleft palate fetuses at 11-13⁺⁶ weeks were obtained prospectively. 2D ultrasound views included the coronal view of the retronasal triangle and the midsagittal view of the face. 3D-CRV views were analyzed by multiplanar mode display. The pregnancy outcomes of all fetuses were determined during the follow-up period.

Results

In our study, 124 fetuses were recruited, including 100 healthy fetuses and 24 cleft palate fetuses. The cleft palate with lip was observed in 23 fetuses (bilateral in 15, unilateral in 6, median in 2), and one cleft palate was only found in the abnormal group. The bilateral (n = 12) and median (n = 2) cleft palates with lips and the cleft palate alone (n = 1) were associated with other anatomical or chromosomal abnormalities, and one unilateral cleft palate with cleft lip had concomitant NT thickening. In the cleft palate fetus group, 16 fetuses suffered intrauterine death, which was associated with other structural or chromosomal abnormalities in 14 fetuses, seven cases were terminated after consultation, and one was delivered at term. The coronal view of the retronasal triangle and the midsagittal view was easily obtained in all fetuses. 3D-CRV images of palatal parts were clearly obtained in all cases. Unilateral, bilateral, and median cleft palates with cleft lips were visually demonstrated and classified by the 3D-CRV technique.

Conclusion

It is feasible to identify the palate by 3D-CRV in the first trimester in both healthy and cleft palate fetuses. Together with 2D ultrasonography as a complementary diagnostic tool, 3D-CRV is helpful in classifying the cleft palate with a reasonable degree of certainty.

Congenital hypotonia: systematic approach for prenatal detection

OBJECTIVES

Congenital hypotonic conditions are rare and heterogeneous, and some are severely debilitating or lethal. Contrary to its prominent postnatal manifestation, the prenatal presentation of hypotonia is frequently subtle, inhibiting prenatal detection. We aimed to characterize the prenatal sonographic manifestation of congenital hypotonia throughout pregnancy, evaluate the yield of diagnostic tests and propose diagnostic models to increase its prenatal detection.

METHODS

This was a retrospective observational study of singleton pregnancies with congenital hypotonia, diagnosed either prenatally or immediately after birth, at a single tertiary center between the years 2012 and 2020. Prenatally, hypotonia was diagnosed if a fetus showed sonographic or clinical signs suggestive of hypotonia and had a confirmed underlying genetic condition, or in the absence of a known genetic abnormality if the fetus exhibited multiple prominent signs suggestive of hypotonia. Postnatally, it was diagnosed in neonates displaying reduced muscle tone leading to reduced spontaneous movement, reduced swallowing or feeding difficulty. We reviewed the medical records of pregnant patients carrying fetuses subsequently diagnosed with congenital hypotonia and assessed the yield of ultrasound scans, fetal magnetic resonance imaging, computed tomography and genetic tests. The detection rate of sonographic signs suggesting fetal hypotonia was calculated. The prevalence of non-specific signs, including polyhydramnios, persistent breech presentation, intrauterine growth restriction and maternal perception of reduced fetal movement, were compared between the study group and the local liveborn singleton population. Potential detection rates of different theoretical semiotic diagnostic models, differing in the threshold for referral for a targeted scan, were assessed based on the cohort's data.

RESULTS

The study group comprised 26 cases of congenital hypotonia, of which 10 (38.5%) were diagnosed prenatally, and the controls included 95 105 singleton live births, giving a prevalence of congenital hypotonia of 1:3658. Nuchal translucency thickness and the early anomaly scan at 13-17 weeks were normal in all 22 and 23 cases, respectively, in which this was performed. The mid-trimester scan performed at 19-25 weeks was abnormal in four of 24 (16.7%) cases. The overall prenatal detection rate of congenital hypotonic conditions in our cohort was 38.5%. Only cases which underwent a targeted scan were detected and, among the 16 cases which underwent this scan, the prenatal detection rate was 62.5% compared with 0% in pregnancies that did not undergo this scan (P = 0.003). An abnormal genetic diagnosis was obtained in 21 (80.8%) cases using the following modalities: chromosomal microarray analysis (CMA) in two (9.5%), whole-exome sequencing (WES) in 14 (66.7%) and methylation analysis in five (23.8%). CMA was abnormal in 8% (2/25) of the cases and WES detected a causative genetic mutation in 87.5% (14/16) of the cases in which these were performed. Comparison of non-specific signs in the study group with those in the local singleton population showed that hypotonic fetuses had significantly more polyhydramnios (64.0% vs 3.0%, P < 0.0001), persistent breech presentation (58.3% vs 4.2%, P < 0.0001), intrauterine growth restriction (30.8% vs 3.0%, P < 0.0001) and maternal perception of reduced fetal movement (32.0% vs 4.7%, P < 0.0001). Prenatally, the most commonly detected signs supporting a diagnosis of hypotonia were structural anomaly (62.5%, 10/16), reduced fetal movement (46.7%, 7/15), joint contractures (46.7%, 7/15) and undescended testes ≥ 30 weeks (42.9%, 3/7 males). Proposed diagnostic strategies that involved performing a targeted scan for a single non-specific ultrasound sign or two such signs, and then carrying out a comprehensive genetic evaluation for any additional sign, offered theoretical detection rates in our cohort of 88.5% and 57.7%, respectively.

CONCLUSIONS

Congenital hypotonic conditions are rare and infrequently detected prenatally. Sonographic signs are visible from the late second trimester. A targeted scan increases prenatal detection significantly. Comprehensive genetic testing, especially WES, is the cornerstone of diagnosis in congenital hypotonia. Theoretical diagnostic models which may increase prenatal detection are provided. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Fetal Cerebellar Area: Ultrasound Reference Ranges at 13-39 Weeks of Gestation

BACKGROUND AND OBJECTIVES

The present study aims to provide prenatal 2-dimensional ultrasonographic (2D-US) nomograms of the normal cerebellar area.

MATERIALS AND METHODS

This is a prospective cross-sectional analysis of 252 normal singleton pregnancies, ranging from 13 to 39 weeks of gestation. The operator performed measurements of the fetal cerebellar area in the transverse plane using 2D-US. The relationship between cerebellar area and gestational age (GA) was determined through regression equations.

RESULTS

A significant, strong positive correlation was investigated between the cerebellar area with GA (r-value = 0.89), and a positive correlation indicates that with increasing GA, the cerebellar area increased in all the participants of the study. Several 2D-US nomograms of the normal cerebellar area were provided, and an increase of 0.4% in the cerebellar area each week of GA was reported.

CONCLUSIONS

We presented information on the typical dimensions of the fetal cerebellar area throughout gestation. In future studies, it could be evaluated how the cerebellar area changes with cerebellar abnormalities. It should be established if calculating the cerebellar area in addition to the routine transverse cerebellar diameter may help in discriminating posterior fossa anomalies or even help to identify anomalies that would otherwise remain undetected.

Locating Multiple Standard Planes in First-Trimester Ultrasound Videos via the Detection and Scoring of Key Anatomical Structures

OBJECTIVE

This study was aimed at developing a first-trimester standard plane detection (FTSPD) system that can automatically locate nine standard planes in ultrasound videos and investigating its utility in clinical practice.

METHODS

The FTSPD system, based on the YOLOv3 network, was developed to detect structures and evaluate the quality of plane images by using a pre-defined scoring system. A total of 220 videos from two different ultrasound scanners were collected to compare detection performance between our FTSPD system and sonographers with different levels of experience. The quality of the detected standard planes was quantitatively rated by an expert according to a scoring protocol. Kolmogorov-Smirnov analysis was used to compare the distributions of scores across all nine standard planes.

RESULTS

The expert-rated scores indicated that the quality of the standard planes detected by the FTSPD system was on par with that of the planes detected by senior sonographers. There were no significant differences in the distributions of the scores across all nine standard planes. The FTSPD system performed significantly better than junior sonographers in five standard plane types.

CONCLUSION

The results of this study suggest that our FTSPD system has significant potential for detecting standard planes in first-trimester ultrasound screening, which may help to improve the accuracy of fetal ultrasound screening and facilitate early diagnosis of abnormalities. The quality of the standard planes selected by junior sonographers can be significantly improved with the assistance of our FTSPD system.

Prenatal Diagnosis of Isolated Single Umbilical Artery: Incidence, Risk Factors and Impact on Pregnancy Outcomes

Objectives: To assess the incidence of prenatally diagnosed isolated single umbilical artery (iSUA) and its impact on major pregnancy outcomes, as well as to investigate potential risk factors. Materials and methods: A prospective study of singleton pregnancies, undergoing routine anomaly scans at 20⁺⁰-24⁺⁰ weeks of gestation, was carried out from 2018 to 2022. The effect of sonographically detected iSUA on small-for-gestational-age neonates (SGA) and preterm delivery (PTD) was evaluated using parameterized Student's t-test, nonparametric Mann-Whitney U test and the chi-square test. Multivariable logistic regression models were implemented to assess the independent association between iSUA and the main outcomes, as well as with potential risk factors, while adjusting for specific confounders. Results: The study population included 6528 singleton pregnancies and the incidence of prenatally diagnosed iSUA was 1.3%. Prenatally diagnosed iSUA had a statistically significant association with both SGA neonates (aOR: 1.909; 95% CI: 1.152-3.163) and PTD (aOR: 1.903; 95% CI: 1.035-3.498), while no association was identified between this sonographic finding and preeclampsia. With regard to risk factors, conception via assisted reproductive technology (ART) was associated with increased risk of iSUA (aOR: 2.234; 95% CI: 1.104-4.523), while no other independent predictor for the development of this anatomical variation was identified. Conclusions: Prenatally diagnosed iSUA seems to be associated with a higher incidence of SGA and PTD and is more common in pregnancies following ART, which constitutes a novel finding.

Prenatal detection of congenital heart disease at 12-13 gestational weeks: detailed analysis of false-negative cases

OBJECTIVES

To report on the early detection of congenital heart disease (CHD) in low- and high-risk populations managed at our hospital; and perform a detailed analysis of false-negative diagnoses, in order to derive possible recommendations on how to reduce their incidence.

METHODS

This was a retrospective observational study analyzing cases which underwent an ultrasound examination at the end of the first trimester at the Fetal Medicine and Surgery Unit of Gaslini Children's Hospital, Genoa, Italy, in the period January 2015 to December 2021. The study population included both low-risk pregnancies that underwent standard first-trimester combined screening and high-risk ones referred to our unit because of a positive combined test or suspicion of fetal anomalies raised in a regional community hospital. For each case, the following variables were retrieved and analyzed: number of fetuses, maternal body mass index, gestational age at first-trimester screening, whether the pregnancy was low or high risk, nuchal translucency thickness (normal or > 99th  centile), type of CHD, associated extracardiac anomalies, karyotype and pregnancy outcome. For low-risk pregnancies, suspicion of CHD was also recorded. In low-risk cases, sonographic cardiac screening comprised evaluation of the four-chamber view (grayscale and color/power Doppler) and three-vessel-and-trachea view (color/power Doppler). High-risk cases underwent early fetal echocardiography. False-negative cases were categorized according to likely cause of the missed diagnosis, as follows: human factor; technical factor; acoustic-window factor.

RESULTS

Gestational age at ultrasound ranged from 12 + 0 to 13 + 6 weeks (crown-rump length (CRL), 50.1-84.0 mm) in the low-risk group and from 11 + 5 to 13 + 6 weeks (CRL, 45.1-84.0 mm) in the high-risk group. Over the 7-year study period, 7080 pregnancies were evaluated in the first trimester. Of these, 6879 (7167 fetuses) were low-risk and 201 were high-risk cases. In the low-risk group, there were 30 fetuses with CHD (including 15 major and 15 minor CHD), yielding a prevalence of 4.2/1000 (2.1/1000 for major CHD). Nine of the 30 CHD cases were suspected at screening ultrasound (7/15 major CHD). Excluding cases in which the CHD would not be expected to be associated with a modification of the screening views and would therefore not be detectable on screening ultrasound, 7/12 cases of major CHD were detected, corresponding to a sensitivity of 58.3%. Among the 201 high-risk cases, there were 46 fetuses with CHD (including 44 major and two minor CHD), of which 43 were detected, corresponding to a sensitivity for early fetal echocardiography of 93.5%, or 97.7% if the two cases that were unlikely to be detectable on first-trimester screening were excluded. Analysis of the 11 (of 24) false-negative cases that would be expected to be picked up on screening views revealed that human error (image interpretation and/or scanning approach) was involved in all 11 cases and technical factors (excessive color priority (color-balance function) and/or incorrect plane alignment) were present in two. There was impairment of the acoustic window (associated with maternal obesity and/or twin gestation) as a cofactor in five of the 11 cases.

CONCLUSIONS

The sensitivity for detection of major CHD of early cardiac screening in low-risk pregnancy is under 60%, partly due to the natural history of CHD and, it seems, partly relating to human error and technical issues with image quality. Factors associated with false-negative diagnoses may be categorized into three types: human error, technical factors and acoustic-window impairment. We recommend: appropriate assessment with fetal posterior spine; that sufficient time is spent on assessment of the fetal situs; and that color/power Doppler settings are adapted to the individual case. A lower threshold for referring doubtful cases for early fetal echocardiography should be adopted in cases of maternal obesity and in twin gestation. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Short-term outcome after the prenatal diagnosis of right aortic arch

OBJECTIVES

To determine the proportion of children that require surgery in the first year of life and thereafter in order to improve the counseling of parents with a fetus with a right aortic arch (RAA).

METHODS

Fetuses diagnosed with isolated RAA, defined as the absence of intra- or extracardiac anomalies, between 2007 and 2021 were extracted from the prospective registry PRECOR.

RESULTS

In total, 110 fetuses were included, 92 with a prenatal diagnosis of RAA and 18 with double aortic arch (DAA). The prevalence of 22q11 deletion syndrome was 5.5%. Six pregnancies were terminated and five cases were false-positive; therefore, the follow-up consisted of 99 neonates. Surgery was performed in 10 infants (10%) in the first year of life. In total, 25 (25%) children had surgery at a mean age of 17 months. Eight of these 25 (32%) had a DAA. Only one child, with a DAA, required surgery in the first week of life due to obstructive stridor.

CONCLUSIONS

Children with a prenatally diagnosed RAA are at a low risk of acute respiratory postnatal problems. Delivery in a hospital with neonatal intensive care and pediatric cardiothoracic facilities seems only indicated in cases with suspected DAA. Expectant parents should be informed that presently 25% of the children need elective surgery and only incidentally due to acute respiratory distress.

Feasibility of extended ultrasound examination of the fetal brain between 24 and 37 weeks' gestation in low-risk pregnancies

OBJECTIVES

To assess the feasibility of identifying fetal brain structures and anatomic landmarks included in the anterior complex (AC) and posterior complex (PC), as well as the proximal hemisphere (PH).

METHODS

This was a prospective observational multicenter study of healthy pregnant women evaluated by ultrasound screening at 24 to 36 + 6 weeks' gestation. Six physicians performed transabdominal ultrasound, to obtain the planes required to visualize the AC, PC, and PH. Blind analysis by an expert and non-expert operator in fetal neurosonography was used to assess the structures included in each plane view.

RESULTS

In the population studied (n=366), structure detection rates for AC were over 95 %, with an agreement of 96 % when comparing expert and non-expert examiners. Visualization of the corpus callosum crossing the midline was detected in over 97 and 96 % of cases for the AC and PC, respectively, with an agreement of over 96 %. The PH plane, particularly through the posterior access via the mastoid fontanelle, enabled visualization of the proximal anatomical structures in almost 95 % of cases. Detection of the corpus callosum through the AC and PC, both proximal/distal germinal matrix (AC) and proximal Sylvian fissure through the anterior access (PH) in the 24-25 + 6, 26-31 + 6 and 32-36 + 6 weeks' gestation groups were successful in over 96 % of cases with high level of agreement.

CONCLUSIONS

Inclusion of AC, PC, and PH later in pregnancy proves feasible with a high level of agreement between both expert and non-expert operators.

Obliterated cavum septi pellucidi: Clinical significance and role of fetal magnetic resonance

INTRODUCTION

The objective of this study was to describe a cohort of fetuses with an ultrasound prenatal diagnosis of obliterated cavum septi pellucidi (oCSP) with the aim to explore the rate of associated malformations, the progression during pregnancy and the role of fetal magnetic resonance imaging (MRI).

MATERIAL AND METHODS

This was a retrospective multicenter international study of fetuses diagnosed with oCSP in the second trimester with available fetal MRI and subsequent ultrasound and/or fetal MRI follow-up in the third trimester. Where available, postnatal data were collected to obtain information on neurodevelopment.

RESULTS

We identified 45 fetuses with oCSP at 20.5 weeks (interquartile range 20.1-21.1). oCSP was apparently isolated at ultrasound in 89% (40/45) and fetal MRI found additional findings in 5% (2/40) of cases, including polymicrogyria and microencephaly. In the remaining 38 fetuses, fetal MRI found a variable amount of fluid in CSP in 74% (28/38) and no fluid in 26% (10/38). Ultrasound follow-up at or after 30 weeks confirmed the diagnosis of oCSP in 32% (12/38) while fluid was visible in 68% (26/38). At follow-up MRI, performed in eight pregnancies, there were periventricular cysts and delayed sulcation with persistent oCSP in one case. Among the remaining cases with normal follow-up ultrasound and fetal MRI findings, the postnatal outcome was normal in 89% of cases (33/37) and abnormal in 11% (4/37): two with isolated speech delay, and two with neurodevelopmental delay secondary to postnatal diagnosis of Noonan syndrome at 5 years in one case and microcephaly with delayed cortical maturation at 5 months in the other.

CONCLUSIONS

Apparently isolated oCSP at mid-pregnancy is a transient finding with the visualization of the fluid later in pregnancy in up to 70% of cases. At referral, associated defects can be found in around 11% of cases at ultrasound and 8% at fetal MRI indicating the need for a detailed evaluation by expert physicians when oCSP is suspected.

Algorithmic approach to neuroradiological diagnosis with pre-natal MRI: non-visualization of the fetal cavum septi pellucidi on mid-trimester screening ultrasound

ADVANCES IN KNOWLEDGE

A systematic approach by the radiologist to analysis of imaging and other clinical data in the fetus with absent septal leaflets suspected on ultrasound will improve diagnostic efficiency, accuracy, and pre-natal counselling.

[Cleft lip and palate : One of the most frequent congenital malformations]

With a frequency of 1 per 500 live births, a cleft lip and palate is one of the most frequent congenital malformations. Untreated, it leads to disturbances in feeding, speech, hearing, tooth position and esthetics. A multifactorial genesis is assumed. The fusion of the different facial processes takes place in the first 3 months of pregnancy and a cleft can develop during this time. Surgical treatment includes the early anatomical and functional restoration of the affected structures within the first year of life in order to enable normal intake of food, articulation, nasal breathing and middle ear ventilation. Breastfeeding is possible in children with a cleft formation but alternative feeding methods, such as finger feeding, often have to be used. In addition to the surgery for primary closure of the cleft, otorhinolaryngological (ENT) interventions, speech therapy, orthodontic treatment as well as other surgical interventions are part of the interdisciplinary treatment concept.

Fetal Hands: A Comprehensive Review of Prenatal Assessment and Diagnosis Over the Past 40 Years

Fetal skeletal dysplasias involving limbs and hands are rare congenital malformations. Prenatal two-dimensional ultrasound diagnosis of fetal limb defects has a sensitivity of about 30%; however, an increased detection rate may be obtained using three-dimensional (3-D) ultrasound in the rendering mode. 3-D ultrasound may be used as a complementary method providing additional information. Currently, magnetic resonance imaging (MRI), with the emergence of ultrafast imaging techniques and new sequences, allows for better diagnosis of several fetal skeletal dysplasias such as limb reduction defects and neuromuscular disorders. 3-D volumetric images from ultrasound or MRI scan data allow 3-D ultrasound reconstructions of virtual/physical models, and virtual reality can help researchers to improve our understanding of both normal and abnormal fetal limb/hand anatomy. In this article, we review the embryological development of fetal hands and their main anomalies including prenatal diagnostic methods, genetic counseling, the role of orthopedic and plastic surgery reconstruction, and new perspectives in fetal surgery.

Fetal anomaly diagnosis and termination of pregnancy

The aim of this review was to discuss bioethics in prenatal diagnosis and health care after recent legislative and judicial changes affecting reproductive rights, such as the repeal of 'Roe v. Wade' in the United States. We recognize that abortion involves particular moralities that are not universal or shared by all cultures, groups, and individuals. We reviewed the historical aspects of embryology and personhood, fetal morbidity and mortality, and parental options for prenatal diagnostic testing. We examined relevant ethical issues including informed consent, the emergence of fetal pain, reproductive autonomy, the fiduciary responsibilities of pregnant mothers, and the obligations of physicians caring for the maternal-fetal dyad. The code of medical ethics includes respect for decisional privacy and the protection of information shared in confidence. When a fetal anomaly is diagnosed, pregnant mothers must be informed about the risks, burdens, and alternatives in either continuing or terminating the pregnancy. Parental choice should include the right to refuse testing, the informed choice not to know about certain genetic test results, and the right to make informed decisions about the best interests of the future child. In the diagnosis and care of fetal anomalies, moral dilemmas arise. Before fetal viability, the mother's autonomy, sense of beneficence, and personal values should be trusted and respected. Perinatal palliative care should be available to pregnant mothers whose anomalous fetus is carried to birth.

Association of placental and umbilical cord characteristics with cerebral palsy: national cohort study

OBJECTIVES

Cerebral palsy (CP) is a group of movement disorders usually diagnosed in childhood. A substantial proportion are thought to be caused by antenatal events. Abnormalities of the umbilical cord and placenta are associated with an increased risk of adverse neonatal outcomes, but it is unclear whether these conditions also carry an increased risk of CP. We aimed to determine whether abnormalities of the umbilical cord or placenta are associated with CP and assess if these associations differ by sex of the child or gestational age at birth.

METHODS

We performed a national cohort study by linking data from The Medical Birth Registry of Norway with other national registries. All liveborn singletons born between 1999 and 2017 (n = 1 087 486) were included and followed up until the end of 2019. Diagnoses of CP were provided by the Norwegian National Insurance Scheme and the Norwegian Patient Register. We used generalized estimating equations and multilevel log binomial regression to calculate relative risks (RR), adjusted for year of birth, and stratified analyses were carried out based on sex and gestational age at birth. Exposures were abnormal umbilical cord (velamentous or marginal insertion, single umbilical artery (SUA), knots and entanglement), and placental abnormalities (retained placenta, placental abruption and previa).

RESULTS

A total of 2443 cases with CP (59.8% males) were identified. Velamentous cord insertion (adjusted RR (aRR), 2.11 (95% CI, 1.65-2.60)), cord knots (aRR, 1.53 (95% CI, 1.15-2.04)) and placental abnormalities (placenta previa (aRR, 3.03 (95% CI, 2.00-4.61)), placental abruption (aRR, 10.63 (95% CI, 8.57-13.18)) and retained placenta (aRR, 1.71 (95% CI, 1.32-2.22))) carried an increased risk of CP. Velamentous cord insertion was associated with CP regardless of gestational age or sex. A retained placenta was associated with a 2-fold increased risk for CP in males, while the associations of SUA and cord knot with CP were significant only among females.

CONCLUSIONS

The detection of placental and umbilical cord abnormalities may help identify children at increased risk of CP. The associations between placental or umbilical cord abnormalities and the risk of CP do not vary substantially with gestational age at birth or sex of the child. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Ultrasound and fetal magnetic resonance imaging: Clinical performance in the prenatal diagnosis of orofacial clefts and mandibular abnormalities

Cleft lip, with or without cleft palate, is the most common congenital craniofacial anomaly and the second most common birth defect worldwide. Micrognathia is a rare facial malformation characterized by small, underdeveloped mandible and frequently associated with retrognathia. Second- and third-trimester prenatal ultrasound is the standard modality for screening and identification of fetal orofacial abnormalities, with a detection rate in the low-risk population ranging from 0% to 73% for all types of cleft. The prenatal ultrasonography detection can also be performed during the first trimester of pregnancy. Given the potential limitations of obstetric ultrasound for examining the fetal face, such as suboptimal fetal position, shadowing from the surrounding bones, reduce amniotic fluid around the face, interposition of fetal limbs, umbilical cord and placenta, and maternal habitus/abdominal scars, the use of adjunct imaging modalities can enhance prenatal diagnosis of craniofacial anomalies in at-risk pregnancies. Fetal magnetic resonance imaging (MRI) is a potentially useful second-line investigation for the prenatal diagnosis of orofacial malformations with a pooled sensitivity of 97%. In this review, we discuss the role of ultrasound and fetal MRI in the prenatal assessment of abnormalities of the upper lip, palate, and mandible.

Improving prenatal detection of abdominal supraumbilical anomalies: The sonographic examination of fetal anechoic spaces of upper abdomen revisited

Visualization of the axial plane of the fetal abdomen is mandatory to obtain abdominal biometry in the assessment of fetal growth in the second and third trimesters. The main anatomic landmarks that must be identified in this view include the fetal stomach and the intrahepatic portion of the umbilical vein, which are easily identifiable as they appear anechoic on ultrasound. The gallbladder is the other prominent anechoic structure in this plane. Focused study of the morphological characteristics of, and spatial relationship among, these three anechoic spaces is a simple technique to detect anomalies involving fetal upper abdominal organs. In this review, the sonographic features of those conditions that can be detected using this technique, which was termed the Fetal Examination of the Anechoic Spaces of upper abdomen Technique (FEAST), are classified and illustrated.

Associations, follow up data, and postnatal outcome of antenatally diagnosed Urinary Tract Dilatation - Five-year single tertiary center experience from South India

BACKGROUND

Urinary tract dilatations (UTD) are frequently diagnosed during Mid-Trimester Anomaly Scan (MTAS), at which time, given their variable progression and heterogeneous classification systems, offering suitable counsel to the couple is challenging.

OBJECTIVE

Based on postnatal data, we aimed to guide parental counseling, and further evaluation of UTD diagnosed at MTAS. Specifically, the utility of multi-disciplinary UTD classification system was tested.

METHODS

A retrospective observational study of all UTDs included from five years (2015-2020) MTAS register. The multi-disciplinary UTD classification system was used for antenatal/postnatal UTD categorization. Follow-up data were obtained from case records until the current age of children (2-6 years).

RESULTS

Out of 527 fetal abnormalities, 103 had UTD at MTAS. Based on the third-trimester ultrasound, 49 were low-risk UTD A1, and 44 were increased-risk UTD A2-3 (including the nineteen UTD A1 at MTAS worsened to A2-3 by third-trimester). On postnatal follow-up of UTD A1 and A2-3, respectively, neonatal UTD P2/P3 was seen in 2% and 40.9%; complete spontaneous resolution was seen in 79.5% and 43.18%; none and 22.7% underwent surgical intervention; persistent P2/P3 UTD were seen on follow-up in 2% and 4.5% (excluding those who needed surgery); impaired renal function was seen in none and 36.3%, and recurrent UTI in 8.1% and 34.09%. The subgroup with progressive UTD (from A1 to A2-3 by third-trimester ultrasound) formed 43% of the final UTD A2-3 category. Among these 19 cases, surgical intervention was performed in eight (42%); impaired renal function was seen in 7 cases (36.8%), and recurrent UTI was seen in eight (42%).

DISCUSSION

Given the diverse classification systems for UTD, ours is the second Indian data proving the prognostic utility of multi-disciplinary UTD classification system, specifically at third trimester scan, based on postnatal outcome. In contrast to published guidelines, our data suggests follow-up for renal pelvis anteroposterior diameter (APD) of 4-7 mm at MTAS, as some may worsen. Similar progression has been noted in other Indian studies, but the classification systems are different. Contrary to the published literature, we could not suggest a renal APD cut-off as a single criterion to predict surgical intervention. Significant limitations are retrospective observational design and multiple sonographers.

CONCLUSION

Our data helps guide parental counseling and further evaluation for UTD diagnosed at MTAS. The multi-disciplinary Consensus UTD Classification system, was helpful in prognostication.

Fetal cavum septum pellucidum nomogram and its relationship with fetal Doppler: a prospective study of a Turkish population

Aim: Septum pellucidum is a thin membrane with right and left leaves, and cavum septum pellucidum (CSP) is formed in the intermembrane region. This study investigates CSP nomogram dimensions for all trimesters in the Turkish population. In addition, the relationship between fetal Doppler flow and CSP size was investigated in this study. Methods: This study was designed as a prospective cohort between 2019-2020. Pregnant women between 19-42 weeks who were followed up at XXX, Department of Obstetrics and Gynecology were included in the study. (blind review) Results: A total of 517 fetuses meeting our criteria were included in this prospective study. In the second trimester (19-28 weeks) CSP width (4.12±0.88 vs. 4.91±1.42, p < 0.001) and length (7.95±1.04 vs. 9.48±2.19, p < 0.001) were significantly higher than in the third trimester (28-42 weeks). While the mean CSP width increased up to 32th weeks, there was no clear increase-decrease pattern between 32th-38th weeks, and it was observed to decrease after 38th weeks. The mean CSP length increased up to 29th weeks, while there was no clear increase-decrease pattern between 29th-38th weeks, but decreased after 38th weeks. While a significant correlation was observed between gestational week and CSP width (r = 0.118, p = 0.010), there was no significant correlation between CSP length (r = 0.086, p =0.062). A significant correlation was observed between biparietal diameter (BPD) and CSP width (r = 0.180, p < 0.001) and length (r = 0.202, p < 0.001), but not with head circumference (HC). There was a significant correlation between middle cerebral artery (MCA) systolic/diastolic ratio (S/D) (r = 0.185, p < 0.001), pulsatility index (PI) (r = 0.210, p < 0.001) and resistive index (RI) (r = 0.233, p < 0.001) and CSP length, but not with CSP width. Conclusion: Turkish population fetal CSP nomogram is presented in this study. Fetal middle cerebral artery Doppler measurements (S/D, PI, and RI) showing cerebral blood flow correlate with CSP length, but not with CSP width. There was no correlation between fetal umbilical artery Doppler measurements and CSP sizes. The results pave the way for population-based studies with much larger samples.

Assessing maternal cardiac function by obstetricians: technique and reference ranges

BACKGROUND

A strong body of evidence has now coalesced indicating that some obstetrical syndromes may result from maladaptive responses of the maternal cardiovascular system. Longitudinal studies have shown that these changes are complex and present before the clinical recognition of preeclampsia and fetal growth restriction, suggesting that hemodynamic maladaptation may play an etiologic role in obstetrical complications. Chronic hypertension is one of the most frequent complications of pregnancy, and recent evidence suggests that control of mild hypertension in early pregnancy improves outcome. The management of chronic hypertension can be improved by understanding specific cardiovascular hemodynamic abnormalities such as increased cardiac output or increased systemic vascular resistance, which can respond to either beta or calcium channel blockers, depending on the hemodynamic findings. Evaluation of maternal cardiac function has not been previously available to obstetrical healthcare providers using diagnostic ultrasound equipment used for fetal evaluation.

OBJECTIVE

Obstetrical ultrasound machines may be configured for various probes (endovaginal, abdominal, 3D/4D, and cardiac). This study used a cardiac probe placed in the suprasternal notch to image and measure the descending aorta diameter and the velocity time integral using pulsed and continuous wave Doppler ultrasound in normal pregnant women between 11 and 39 weeks of gestation. These measurements were followed by computation of maternal left ventricular preload, afterload, contractility, and blood flow.

STUDY DESIGN

This was a prospective cross-sectional study. A total of 400 pregnant women were recruited between 11 and 39 weeks of gestation. Imaging of the maternal aortic arch was performed by placing a cardiac probe in the suprasternal notch to identify the aortic arch using 2D and color Doppler ultrasound. The end-systolic diameter of the aorta was measured at the junction of the left subclavian artery with the descending aorta, which was followed by insonation of the descending aorta to obtain the Doppler waveform. Following insonation of the descending aorta, measurements of the aortic diameter, velocity time integral, ejection time, mean pressure gradient, heart rate, maternal weight and height, and systolic and diastolic blood pressures were entered into an Excel spreadsheet to compute the following: (1) preload measurements of stroke volume, stroke volume index, and stroke work index; (2) afterload measurements of systemic vascular resistance and the potential-to-kinetic energy ratio; (3) contractility measurements of inotropy and the Smith-Madigan inotropy index; and (4) blood flow measurements of cardiac output and the cardiac output index. Fractional polynomial regression analysis was performed for each of the above measurements using gestational age as the independent variable.

RESULTS

The diastolic and mean arterial blood pressure decreased from 11 to 18 weeks of gestation and then increased until term. The afterload measurements demonstrated similar characteristics, as all values decreased from 11 weeks until the mid and late second trimester, after which all values increased until term. Changes in contractility demonstrated an increase from 11 weeks to 25 to 28 weeks, followed by a decline until term. Changes in blood flow demonstrated an increase from 11 to 27 weeks and then declined until term. The continuous wave Doppler values were greater than the pulsed Doppler values except for the contractility measurements. Examples of abnormal cardiac measurements were identified in pregnant patients with hypertension and fetal growth restriction. An Excel calculator was created to provide quick computation of z-score measurements and their corresponding centiles described in this study.

CONCLUSION

The technique for evaluation of maternal cardiac function described in this study would allow screening of maternal left ventricular preload, afterload, contractility, and blood flow in the obstetrical clinical milieu once a cardiac probe is acquired for obstetrical ultrasound machines used for fetal evaluation. The above measurements would allow the clinician to select appropriate hypertensive medication on the basis of the results of the evaluation of the maternal left ventricle.

A review on deep-learning algorithms for fetal ultrasound-image analysis

Deep-learning (DL) algorithms are becoming the standard for processing ultrasound (US) fetal images. A number of survey papers in the field is today available, but most of them are focusing on a broader area of medical-image analysis or not covering all fetal US DL applications. This paper surveys the most recent work in the field, with a total of 153 research papers published after 2017. Papers are analyzed and commented from both the methodology and the application perspective. We categorized the papers into (i) fetal standard-plane detection, (ii) anatomical structure analysis and (iii) biometry parameter estimation. For each category, main limitations and open issues are presented. Summary tables are included to facilitate the comparison among the different approaches. In addition, emerging applications are also outlined. Publicly-available datasets and performance metrics commonly used to assess algorithm performance are summarized, too. This paper ends with a critical summary of the current state of the art on DL algorithms for fetal US image analysis and a discussion on current challenges that have to be tackled by researchers working in the field to translate the research methodology into actual clinical practice.

[Gestational diabetes mellitus (Update 2023)]

Gestational diabetes (GDM) is defined as any degree of glucose intolerance with onset during pregnancy and is associated with increased feto-maternal morbidity as well as long-term complications in mothers and the offspring. Women detected to have diabetes early in pregnancy receive the diagnosis of overt, non-gestational, diabetes (glucose: fasting ≥ 126 mg/dl, spontaneous ≥ 200 mg/dl or HbA_1c ≥ 6.5% before 20 weeks of gestation). GDM is diagnosed by an oral glucose tolerance test (oGTT) or increased fasting glucose (≥ 92 mg/dl). Screening for undiagnosed type 2 diabetes at the first prenatal visit is recommended in women at increased risk (history of GDM/pre-diabetes; malformation, stillbirth, successive abortions or birth weight > 4500 g previously; obesity, metabolic syndrome, age > 35 years, vascular disease; clinical symptoms of diabetes (e.g. glucosuria) or ethnic origin with increased risk for GDM/T2DM (Arab, South- and Southeast Asian, Latin American)) using standard diagnostic criteria. Performance of the oGTT (120 min; 75 g glucose) may already be indicated in the first trimester in high-risk women but is mandatory between gestational week 24-28 in all pregnant women with previous non-pathological glucose metabolism. Following WHO recommendations, which are based on the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study, GDM is defined, if fasting venous plasma glucose is ≥ 92 mg/dl or 1 h ≥ 180 mg/dl or 2 h ≥ 153 mg/dl after glucose loading (international consensus criteria). In case of one pathological value a strict metabolic control is mandatory. After bariatric surgery we do not recommend to perform an oGTT due to risk of postprandial hypoglycemia. All women with GDM should receive nutritional counseling, be instructed in blood glucose self-monitoring and motivated to increase physical activity to moderate intensity levels-if not contraindicated (Evidence level A). If blood glucose levels cannot be maintained in the therapeutic range (fasting < 95 mg/dl and 1 h after meals < 140 mg/dl, Evidence level B) insulin therapy should be initiated as first choice (Evidence level A). Maternal and fetal monitoring is required in order to minimize maternal and fetal/neonatal morbidity and perinatal mortality. Regular obstetric examinations including ultrasound examinations are recommended (Evidence level A). Neonatal care of GDM offspring at high risk for hypoglycaemia includes blood glucose measurements after birth and if necessary appropriate intervention. Monitoring the development of the children and recommendation of healthy lifestyle are important issues to be tackled for the whole family. After delivery all women with GDM have to be reevaluated as to their glucose tolerance by a 75 g oGTT (WHO criteria) 4-12 weeks postpartum. Assessment of glucose parameters (fasting glucose, random glucose, HbA_1c or optimally oGTT) are recommended every 2-3 years in case of normal glucose tolerance. All women have to be instructed about their increased risk of type 2 diabetes and cardiovascular disease at follow-up. Possible preventive meassures, in particular lifestyle changes as weight management and maintenance/increase of physical activity should be discussed (evidence level A).

Clinical workflow of sonographers performing fetal anomaly ultrasound scans: deep-learning-based analysis

OBJECTIVE

Despite decades of obstetric scanning, the field of sonographer workflow remains largely unexplored. In the second trimester, sonographers use scan guidelines to guide their acquisition of standard planes and structures; however, the scan-acquisition order is not prescribed. Using deep-learning-based video analysis, the aim of this study was to develop a deeper understanding of the clinical workflow undertaken by sonographers during second-trimester anomaly scans.

METHODS

We collected prospectively full-length video recordings of routine second-trimester anomaly scans. Important scan events in the videos were identified by detecting automatically image freeze and image/clip save. The video immediately preceding and following the important event was extracted and labeled as one of 11 commonly acquired anatomical structures. We developed and used a purposely trained and tested deep-learning annotation model to label automatically the large number of scan events. Thus, anomaly scans were partitioned as a sequence of anatomical planes or fetal structures obtained over time.

RESULTS

A total of 496 anomaly scans performed by 14 sonographers were available for analysis. UK guidelines specify that an image or videoclip of five different anatomical regions must be stored and these were detected in the majority of scans: head/brain was detected in 97.2% of scans, coronal face view (nose/lips) in 86.1%, abdomen in 93.1%, spine in 95.0% and femur in 92.3%. Analyzing the clinical workflow, we observed that sonographers were most likely to begin their scan by capturing the head/brain (in 24.4% of scans), spine (in 23.2%) or thorax/heart (in 22.8%). The most commonly identified two-structure transitions were: placenta/amniotic fluid to maternal anatomy, occurring in 44.5% of scans; head/brain to coronal face (nose/lips) in 42.7%; abdomen to thorax/heart in 26.1%; and three-dimensional/four-dimensional face to sagittal face (profile) in 23.7%. Transitions between three or more consecutive structures in sequence were uncommon (up to 13% of scans). None of the captured anomaly scans shared an entirely identical sequence.

CONCLUSIONS

We present a novel evaluation of the anomaly scan acquisition process using a deep-learning-based analysis of ultrasound video. We note wide variation in the number and sequence of structures obtained during routine second-trimester anomaly scans. Overall, each anomaly scan was found to be unique in its scanning sequence, suggesting that sonographers take advantage of the fetal position and acquire the standard planes according to their visibility rather than following a strict acquisition order. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Considering the Effects and Maternofoetal Implications of Vascular Disorders and the Umbilical Cord

The umbilical cord is a critical anatomical structure connecting the placenta with the foetus, fulfilling multiple functions during pregnancy and hence influencing foetal development, programming and survival. Histologically, the umbilical cord is composed of three blood vessels: two arteries and one vein, integrated in a mucous connective tissue (Wharton's jelly) upholstered by a layer of amniotic coating. Vascular alterations in the umbilical cord or damage in this tissue because of other vascular disorders during pregnancy are worryingly related with detrimental maternofoetal consequences. In the present work, we will describe the main vascular alterations presented in the umbilical cord, both in the arteries (Single umbilical artery, hypoplastic umbilical artery or aneurysms in umbilical arteries) and the vein (Vascular thrombosis, aneurysms or varicose veins in the umbilical vein), together with other possible complications (Velamentous insertion, vasa praevia, hypercoiled or hypocoiled cord, angiomyxoma and haematomas). Likewise, the effect of the main obstetric vascular disorders like hypertensive disorders of pregnancy (specially pre-eclampsia) and chronic venous disease on the umbilical cord will also be summarized herein.

A guiding approach of Ultrasound scan for accurately obtaining standard diagnostic planes of fetal brain malformation

BACKGROUND

Standard planes (SPs) are crucial for the diagnosis of fetal brain malformation. However, it is very time-consuming and requires extensive experiences to acquire the SPs accurately due to the large difference in fetal posture and the complexity of SPs definitions.

OBJECTIVE

This study aims to present a guiding approach that could assist sonographer to obtain the SPs more accurately and more quickly.

METHODS

To begin with, sonographer uses the 3D probe to scan the fetal head to obtain 3D volume data, and then we used affine transformation to calibrate 3D volume data to the standard body position and established the corresponding 3D head model in 'real time'. When the sonographer uses the 2D probe to scan a plane, the position of current plane can be clearly show in 3D head model by our RLNet (regression location network), which can conduct the sonographer to obtain the three SPs more accurately. When the three SPs are located, the sagittal plane and the coronal planes can be automatically generated according to the spatial relationship with the three SPs.

RESULTS

Experimental results conducted on 3200 2D US images show that the RLNet achieves average angle error of the transthalamic plane was 3.91±2.86°, which has a obvious improvement compared other published data. The automatically generated coronal and sagittal SPs conform the diagnostic criteria and the diagnostic requirements of fetal brain malformation.

CONCLUSIONS

A guiding scanning method based deep learning for ultrasonic brain malformation screening is firstly proposed and it has a pragmatic value for future clinical application.