Antenatal diagnosis of agenesis of the corpus callosum

Perinatal clinical course of Vici syndrome associated with novel EPG5 variants: unique cardiac changes and difficulty with foetal diagnosis

Vici syndrome is a genetic disorder involving autophagy dysfunction caused by biallelic pathogenic variants in ectopic P-granules 5 autophagy tethering factor (EPG5). We report the perinatal clinical course of a neonate with Vici syndrome with a unique cardiac presentation. Foetal ultrasonography (US) detected right ventricular hypertrophy, hypoplastic left ventricle and narrowing of the foramen ovale, which were alleviated after birth. Agenesis of the corpus callosum and cerebellar hypoplasia were missed antenatally. After delivery, the patient was clinically diagnosed with Vici syndrome and two novel pathogenic mutations were detected in EPG5 The T-cell receptor repertoire was selectively skewed in the Vβ2 family. Immunological prophylaxis and tube feeding were introduced. Early diagnosis helps parents accept their child's prognosis and decide on a care plan. However, US has limited potential to detect clinical phenotypes associated with Vici syndrome. Foetal MRI may detect the characteristic abnormalities and contribute to antenatal diagnosis.

Tela-choroidea-to-anterior-cerebral-artery distance (TACAD): novel marker on color Doppler to identify fetuses with complete or partial agenesis of corpus callosum

OBJECTIVES

To assess objectively the course of the anterior cerebral artery (ACA) by measuring its distance to the tela choroidea in the midsagittal view, and to compare this distance in normal fetuses with that in those with agenesis of the corpus callosum (ACC), a condition known to be associated with an abnormal course of the ACA.

METHODS

The tela-choroidea-to-anterior-cerebral-artery distance (TACAD) was measured in the midsagittal view of the brain on color Doppler, between the anterior border of the tela choroidea and the ACA at the level of the callosal genu. Reference ranges in relation to gestational age were established in a prospective, cross-sectional study of 253 normal healthy fetuses between 19 and 36 weeks of gestation. The study group included fetuses with complete ACC (n = 28) or partial ACC (n = 18).

RESULTS

TACAD of normal fetuses showed an increase during the second half of pregnancy, with a mean value of 10.1 mm and 14.2 mm at 22 and 30 weeks of gestation, respectively. All (28/28) fetuses with complete ACC and 83% (15/18) of those with partial ACC had significantly shorter TACAD, with mean values of 3.9 mm and 6.6 mm, respectively.

CONCLUSIONS

TACAD is a measurement that is simple to obtain during fetal color Doppler neurosonography, which enables quantification of the course of the ACA and pericallosal artery. TACAD is shorter in fetuses with complete or partial ACC than in normal fetuses and provides an objective, quantifiable value, rather than merely descriptive information. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Comparison of Prenatal Ultrasound and Autopsy Findings of Fetuses Terminated in Second Trimester: A Five-Year Experience of a Tertiary Center

Objective: The aim of this study is to compare the prenatal ultrasonography (US) and the autopsy findings of the fetuses of 12-24th gestational weeks. Methods: This retrospective study comprises 84 fetuses autopsied. The correlation between US and autopsy findings was classified into four categories: (A) Compatible, (B) Minor findings added, (C) Major findings added, and (D) Incompatible. Results: Malformations were the most common medical termination indication. The most frequent findings at autopsy were multiple system findings followed by central nervous system. Prenatal US and autopsy findings were completely compatible in 48 fetuses (57.1%), while additional minor and major autopsy findings were found in 26 (31.0%) and 4 (4.8%), respectively. Autopsy and US findings were incompatible in 6 fetuses (7.1%). Conclusion: Prenatal ultrasound and fetal autopsy are complementary tools to obtain detailed and complete diagnosis of fetal anomalies and fetal autopsy is still a valuable tool to obtain further diagnostic information.

Evaluation of medical malpractice claims in obstetric ultrasonography: Opinion of The Council of Forensic Medicine in Turkey

AIM

The Council of Forensic Medicine is an institution affiliated with the Ministry of Justice in the Republic of Turkey which acts in an official oversight capacity in cases of alleged medical malpractice in forensic medical science. Sonographers may face judicial sanctions as a result of ultrasonography examinations that they do not perform according to current guidelines. In this study we focused our attention to claims of medical malpractice related to obstetric ultrasonography that had been referred to the Council of Forensic Medicine. Our aim was to investigate the causes of malpractice claims related to obstetric ultrasonography and to present the expert opinions of our council about these claims in the light of literature. We have also planned to discuss what can be done with current guideline information to prevent situations that cause malpractice claims.

MATERIALS AND METHODS

The study herein was performed on 73 claims of medical malpractice in obstetric ultrasonography findings, all of which were referred by forensic authorities to the Second Specialization Board of Council Forensic Medicine from 2014 to 2018. A retrospective review of the reports generated from information contained within case files illuminates the reasoning behind medical error claims. Among the reasons examined are features of the ultrasonographic evaluation (number, week of examination, health institution), the traits of the evaluating physicians (institutions, branches, academic titles), congenital anomalies detected after birth, and maternal age.

RESULTS

Analysis of the data shows that 79.5% of ultrasonographic examinations leading to claims of medical malpractice were performed in private health institutions. All cases of medical malpractice claims were associated with undiagnosed congenital anomalies, and that the form for informed consent was obtained for only 19.1% of cases that underwent second level ultrasonographic examination. Further, 53.3% of cases with congenital anomalies subject to litigation were anomalies of the extremities, and all four cases of alleged malpractice within obstetric ultrasonography were associated with extremity anomalies. The variety of academic titles of physicians performing the ultrasonographic examinations was not statistically significant. It was concluded that two ultrasonography examinations performed by two nuclear medicine specialists were not in accordance with medical norms.

CONCLUSION

Although organizations such as AIUM, ACR, and ACOG try to set standards for ultrasound examination through practice guidelines, it is difficult to establish optimal standards for ultrasonographic examination. In light of the guidelines created by the above organizations, each country should set its own standard based on their own socioeconomic and health data. We conclude that it is not appropriate for obstetric ultrasonographic examinations to be performed by specialists in fields such as nuclear medicine, where ultrasonographic examinations are not a part of the core training curriculum. Obtaining a signed informed consent form from the patient prior to the second level ultrasonography examination will be useful for medicolegal defense purposes should a subsequent claim of malpractice be filed.

Improved neurodevelopmental prognostication in isolated corpus callosal agenesis: fetal magnetic resonance imaging-based scoring system

OBJECTIVES

Corpus callosal agenesis (CCA) is one of the most common brain malformations and is generally associated with a good outcome when isolated. However, up to 25% of patients are at risk of neurodevelopmental delay, which currently available clinical and imaging parameters are inadequate to predict. The objectives of this study were to apply and validate a fetal magnetic resonance imaging (MRI) anatomical scoring system in a cohort of fetuses with isolated CCA and to evaluate the correlation with postnatal neurodevelopmental outcome.

METHODS

This was a retrospective cohort study of cases of prenatally diagnosed isolated CCA (as determined on ultrasound and MRI), with normal karyotype and with known postnatal neurodevelopmental outcome assessed by standardized testing. A fetal brain MRI anatomical scoring system based on seven categories (gyration, opercularization, temporal lobe symmetry, lamination, hippocampal position, basal ganglia and ventricular size) was developed and applied to the cohort; a total score of 0-11 points could be given, with a score of 0 representing normal anatomy. Images were scored independently by two neuroradiologists blinded to the outcome. For the purpose of assessing the correlation between fetal MRI score and neurodevelopmental outcome, neurodevelopmental test results were scored as follows: 0, 'below average' (poor outcome); 1, 'average'; and 2, 'above average' (good outcome). Spearman's rank coefficient was used to assess correlation, and inter-rater agreement in the assessment of fetal MRI score was calculated.

RESULTS

Twenty-one children (nine females (42.9%)) fulfilled the inclusion criteria. Thirty-seven fetal MRI examinations were evaluated. Mean gestational age was 28.3 ± 4.7 weeks (range, 20-38 weeks). All fetuses were delivered after 35 weeks' gestation with no perinatal complications. Fetal MRI scores ranged from 0 to 6 points, with a median of 3 points. Inter-rater agreement in fetal MRI score assessment was excellent (intraclass correlation coefficient, 0.959 (95% CI, 0.921-0.979)). Neurodevelopmental evaluation was performed on average at 2.6 ± 1.46 years (range, 0.5-5.8 years). There was a significant negative correlation between fetal MRI score and neurodevelopmental outcome score in the three areas tested: cognitive (ρ = -0.559, P < 0.0001); motor (ρ = -0.414, P = 0.012) and language (ρ = -0.565, P < 0.0001) skills. Using fetal MRI score cut-offs of ≤ 3 (good outcome) and ≥ 4 points (high risk for poor outcome), the correct prognosis could be determined in 20/21 (95.2% (95% CI, 77.3-99.2%)) cases.

CONCLUSION

By assessing structural features of the fetal brain on MRI, it may be possible to better stratify prenatally the risk of poor neurodevelopmental outcome in CCA patients. © 2020 Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Heterogeneity in defining fetal corpus callosal pathology: systematic review

OBJECTIVE

Fetal anomalies of the corpus callosum (CC) have been reported in the prenatal imaging literature since 1985, and, especially when isolated, pose challenges for both the patient and fetal medicine specialist. The purpose of this study was to review systematically the literature on prenatally diagnosed abnormalities of the CC, focusing on the terminology used to describe abnormalities other than complete agenesis of the CC, and to assess the heterogeneity of the nomenclature and definitions used.

METHODS

This study was conducted in accordance with the PRISMA statement for reporting systematic reviews. A literature search was performed to identify prospective or retrospective case series or cohort studies, published in English, French, Italian, German or Spanish, reporting fetal imaging findings and describing anomalies of the CC. Quality and risk of bias of the studies were evaluated using the Newcastle-Ottawa scale and a modification of the scale developed by Conde-Agudelo et al. for other fetal imaging studies. The data extracted included the number of patients, the number of different anomalies identified, the descriptive names of the anomalies, and, where applicable, the definitions of the anomalies, the number of cases of each type of anomaly and the biometric charts used. Secondary tests used to confirm the diagnosis, as well as the postnatal or post-termination tests used to ascertain the diagnosis, were also recorded.

RESULTS

The search identified 998 records, and, after review of titles and abstracts and full review of 45 papers, 27 studies were included initially in the review, of which 24 were included in the final analysis. These 24 studies had a broad range of quality and risk of bias and represented 1135 cases of CC anomalies, of which 49% were complete agenesis and the remainder were described using the term partial agenesis or nine other terms, of which five had more than one definition.

CONCLUSIONS

In comparison to the postnatal literature, in the prenatal literature there is much greater heterogeneity in the nomenclature and definition of CC anomalies other than complete agenesis. This heterogeneity and lack of standard definitions in the prenatal literature make it difficult to develop large multicenter pooled cohorts of patients who can be followed in order to develop a better understanding of the genetic associations and neurodevelopmental and psychological outcomes of patients with CC anomalies. As this information is important to improve counseling of these patients, a good first step towards this goal would be to develop a simpler categorization of prenatal CC anomalies that matches better the postnatal literature. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Brain fetal neuroradiology: a beginner's guide

The importance of fetal magnetic resonance imaging (MRI) in the prenatal diagnosis of central nervous system (CNS) anomalies is rapidly increasing. Fetal MRI represents a third level examination usually performed, as early as 18-20 weeks of gestational age, when a second level (expert) neuro-ultrasonography (US) evaluation raises the suspicion of a CNS anomaly or when a genetic disorder is known. Compared to the US, MRI has the advantage to allow a better visualization and characterization of brain structures so to detect anomalies not visible in the US, thus resulting in relevant implications for parent counselling and pregnancy management. Moreover, the improvement of MRI technologies permits to obtain ultrafast sequences, which minimize the drawback of movement artifacts, and to perform advanced studies. This review aims at providing a practical guide for trainees and fellows who are approaching fetal MRI. In the first part, we provide information about indications, safety and protocols based on the state-of-the-art sequences, with a mention on the innovations related to the use of a 3T scanner. The second part is focused on the normal development of the human fetal brain related to its MR appearance, whose knowledge is essential to detect possible abnormalities. The last section briefly describes the most frequent abnormalities in the fetal brain and spine as depicted by MRI.

Comparison between Two-Dimensional and Three-Dimensional Assessments of the Fetal Corpus Callosum: Reproducibility of Measurements and Acquisition Time

The objective of this article was to study the reproducibility and reliability of the fetal corpus callosum measurements between two-dimensional (2D) and three-dimensional (3D) acquisitions. This prospective study enrolled 475 fetuses, monitored between 18 and 38 weeks of gestation by two operators. Starting from a transcerebellar axial plane, 3D and 2D mid-sagittal views of the corpus callosum were obtained. Measurements of length and thickness were performed and underwent quality control by independent reviewers. The acquisition time of the two methods was measured. Means, differences, and linear correlations were analyzed using t-test, regression and Pearson's correlation coefficients, and Bland–Altman's plots. This analysis was performed for each operator to test the interobserver reproducibility. Among the 432 cases measured using both methods, 380 (88%) were validated by quality control. The mean corpus callosum length and thickness were essentially the same using 2D and 3D measurements (2D: 33.8 ± 8.7 vs. 3D: 33.7 ± 8.7 mm, 2D: 2.2 ± 0.4 vs. 3D: 2.2 ± 0.4 mm, respectively; mean ± standard deviation [SD]). Linear regression coefficients and Pearson's coefficients were similar for length (2D: 0.8283 and 0.9191 vs. 3D: 0.8271 and 0.9095), but slightly different regarding thickness (2D: 0.6775 and 0.8231 vs. 3D: 0.5831 and 0.7636). Differences between 2D and 3D measurements, considering Bland–Altman's plots and correlated with gestational age, were acceptable (2D: 0.097 ± 0.559 mm, 3D: 0.004 ± 0.111 mm). The acquisition time required was significantly lower for 3D acquisitions (3D: 25.2 ± 14.5 seconds vs. 2D: 35.1 ± 19.4 seconds, p < 0.01). Linear regression and Pearson's coefficients for the measurements of corpus callosum length and thickness using 2D or 3D acquisitions did not differ between the operators. This study confirmed good reproducibility of corpus callosum assessment by transabdominal 3D acquisitions. The good feasibility in routine scans may lead to better screening for callosal dysgenesis.

Analysis of 270 fetuses with non-visualization of cavum septi pellucidi and vergae on in-utero magnetic resonance imaging

OBJECTIVE

To analyze a large retrospective cohort of fetuses in which the cavum septi pellucidi and vergae (CSPV) was not present or was not in its expected position on in-utero magnetic resonance imaging (iuMRI), in order to describe the possible causes of that finding and provide a diagnostic approach to assess such cases in clinical practice using iuMRI.

METHODS

This was a retrospective study of fetuses that underwent iuMRI at a single institution, over an 18-year period (2000-2017 inclusive), in which the CSPV was not visualized or was abnormal. All iuMRI studies were reviewed and classified as CSPV being not present, disrupted (visualization of remnants of an otherwise normally placed CSPV) or malpositioned (CSPV was present, but not in its expected position). We describe the neuropathology present in each of the groups.

RESULTS

Of the 270 fetuses that met the inclusion criteria, the CSPV was described as malpositioned in 150 (56%), disrupted in 71 (26%) and not present in 49 (18%). Malpositioned CSPV was present only in cases with agenesis of the corpus callosum and three specific patterns of malpositioning are described, depending on the location of the leaflets of the CSPV and fornix. Disrupted CSPV was present in fetuses with hydrocephalus or pathologies causing extensive brain parenchymal injury. Not present CSPV was found in cases with holoprosencephaly or when absence of the CSPV appeared to be an isolated finding.

CONCLUSION

We have described a large cohort of fetuses with non-visualization of a normal CSPV on iuMRI and present a categorical classification system based on the CSPV being not present, disrupted or malpositioned. This approach should help in the diagnosis of the underlying cause of a CSPV abnormality. © 2019 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Fetal Neuroimaging Update

OBJECTIVES

To review the current imaging techniques available for the evaluation of the fetal brain.

FINDINGS

Ultrasound remains the initial screening modality with routine scanning typically performed at 18-20 weeks gestation. When a central nervous system (CNS) abnormality is noted by ultrasound, MRI is increasingly being used to further clarify findings. Fetal MRI has the unique ability to provide high detailed anatomical information of the entire human fetus with high contrast resolution. This technique has grown due to the development of rapid single shot image acquisition sequences, improvement of motion correction strategies and optimizing shimming techniques.

CONCLUSIONS

The assessment of fetal CNS anomalies continues to improve. Advanced MRI techniques have allowed for further delineation of CNS anomalies and have become a cornerstone in the assessment of fetal brain well-being. Those interpreting fetal studies need to be familiar with the strengths and limitations of each exam and be sensitive to the impact discussing findings can have regarding perinatal care and delivery planning. Collaboration with neurologists, neurosurgeons, geneticists, counselors, and maternal fetal specialists are key in providing the best care to the families we treat.

An analysis of 109 fetuses with prenatal diagnosis of complete agenesis of corpus callosum

BACKGROUND

Agenesis of the corpus callosum (ACC) is the most frequent commissural malformation of the brain. It continues to be an important cause of the pregnancy termination associated with the central nervous system (CNS).

OBJECTIVE

The aim of the study is to provide a comprehensive assessment of fetuses with diagnosis of complete ACC, as well as postnatal neurodevelopmental outcomes.

METHODS

The data of 75,843 fetuses were screened for evaluation of complete ACC between 2003 and 2017, and a total of 109 cases with complete ACC were included in the study. ACC was considered isolated when no additional anomalies were detected, and ACC was considered complex when additional anomalies were present.

RESULTS

The prevalence of complete ACC was 9.4 per 10,000 live births, and the incidence was ranged from 1.8 to 16.6 per 10,000 person-years. Patients with isolated ACC had a significantly higher survival when compared with patients with complex ACC (97.4%, n = 38/39 vs. 68.8%, n = 22/32, P = 0.001).The most important cause of death were congenital heart disease and/or respiratory failure during neonatal period. Developmental and intellectual disabilities were significantly higher in the complex ACC cases (P < 0.001). Postnatal neurodevelopmental outcomes were completely normal in 79.4% of cases with isolated ACC.

CONCLUSIONS

Isolated complete ACC is usually associated with a favorable outcome. The most important prognostic factors are the presence or absence of associated congenital anomalies.

Utility of indirect sonographic signs (including cavum septum pellucidum ratio) in midgestational screening for partial agenesis of corpus callosum

PURPOSE

This study was undertaken to evaluate the performance of indirect sonographic signs in detecting partial agenesis of the corpus callosum (pACC) at midgestation, focusing on the cavum septum pellucidum (CSP) ratio.

METHODS

A retrospective case-controlled study of singleton pregnancies was conducted, examining fetuses diagnosed with isolated pACC and normal controls. At midgestational age, fetal head volumes were imaged with 3D US and stored for the evaluation of indirect sonographic findings in axial planes.

RESULTS

Fifteen normal and 15 abnormal fetuses (with pACC) were analyzed. Based on a CSP ratio < 1.5, detection of pACC increased from 66.7% (10/15) to 80% (12/15). All indirect signs proved highly suspicious for pACC (risk ratios > 1).

CONCLUSION

Use of indirect sonographic signs to screen for pACC at midgestation is challenging. However, a low CSP ratio may improve the detection rate, serving as a new indirect sign.

Associated anomalies in cases with agenesis of the corpus callosum

Agenesis of corpus callosum (ACC) is an uncommon congenital anomaly, its etiology is unclear and its pathogenesis is controversial. Cases with ACC often have other non-ACC associated congenital anomalies. The purpose of this study was to assess the prevalence and the types of these associated anomalies in a defined population. The associated anomalies in cases with ACC were collected in all live births, stillbirths, and terminations of pregnancy during 29 years in 387,067 consecutive births in the area covered by our population-based registry of congenital malformations. Of the 99 cases with ACC, representing a prevalence of 2.56 per 10,000, 73 (73.7%) had associated anomalies. There were 16 (16.2%) cases with chromosomal abnormalities, and 13 (13.2%) nonchromosomal recognized dysmorphic conditions including syndromes two each: Aicardi, Dandy-Walker, and fetal alcoholism. Forty-four (44.4%) of the cases had nonsyndromic multiple congenital anomalies (MCA). Anomalies in the musculoskeletal, the urogenital, the central nervous, the cardiovascular, and the digestive systems were the most common other anomalies in the cases with MCA. The anomalies associated with ACC could be classified into a recognizable malformation syndrome in 29 out of the 73 cases (39.7%) with associated anomalies. This study included special strengths: it is population-based, each affected child was examined by a geneticist, all elective terminations were ascertained, and the surveillance for anomalies was continued until 2 years of age. In conclusion the overall prevalence of associated anomalies, three of four cases, emphasizes the need for a screening for other anomalies in cases with ACC.

Accuracy of prenatal ultrasound in the diagnosis of corpus callosum anomalies

Objectives: The main objective of this study was to evaluate the accuracy of prenatal ultrasound to diagnose corpus callosum alterations, compared to prenatal magnetic resonance imaging (MRI), postnatal image techniques (ultrasound and/or MRI), and post-mortem examination in terminated pregnancies.Methods: Retrospective review of 86 cases of prenatal ultrasound diagnosis of corpus callosum anomalies between January 2007 and December 2015 at a third level Maternal Fetal Medicine center. The study reviewed the findings of prenatal ultrasound and MRI, post-mortem examination in cases of termination of pregnancy (TOP) or stillbirths and postnatal ultrasound, and MRI in neonates. The anomalies of corpus callosum (CC) were classified as complete agenesis of the corpus callosum (ACC), partial ACC, or dysgenesis of CC.Results: Fifty-eight (67.4%) cases resulted in TOP, 26 (30.2%) cases opted to continue with the pregnancy and two (2.3%) cases were lost to follow up. Among the 26 cases that continued with the pregnancy, 24 (92.3%) were live births and two (7.7%) were stillborn. All cases in which a third trimester MRI was performed (n = 46) confirmed the prenatal ultrasound diagnosis of CC anomaly. In seven (15.2%) of them, the MRI found additional intracranial findings and in three cases (6.5%) the type of CC anomaly (complete, partial, or dysgenesis) was reclassified (Kappa index: 0.86, 95% CI: 0.71-1.00). CC anomalies were confirmed in 46 (95.8%) of the 48 cases in which a post-mortem examination was available, the type of anomaly being reclassified in three cases (6.3%) (Kappa index: 0.88, 95% CI: 0.75-1.00). Among the 10 cases in which a postnatal ultrasound was performed, the CC anomaly was confirmed in all and the type of anomaly was reclassified in 1 (10%) of them (Kappa index: 0.75, 95% CI: 0.32-1.00).Conclusion: Corpus callosum agenesis can be detected on the routine mid-trimester ultrasound scan. Prenatal ultrasound and MRI can accurately classify the type of CC abnormality. Moreover, third trimester MRI can detect additional intracranial anomalies in 15% of cases.

Neurodevelopmental outcome following prenatal diagnosis of a short corpus callosum

OBJECTIVE

Data regarding the neurodevelopmental outcome of fetal short corpus callosum (CC) diagnosed according to standard reference charts is scarce. The purpose of this study was to assess whether the finding is related to neurodevelopmental delay, and to examine reclassification to normal fetal CC length using CC length/EFW ratio.

METHOD

Historical prospective cohort study including pregnant women who were referred for fetal neurosonogram due to abnormal CC. Short CC was defined below the 5^th percentile according to reference charts. Twenty cases were included in the study group and compared with a control group of 59 normal cases. The patients in the study group were divided into two groups according to CC length/EFW ratio. Children's neurodevelopment was assessed using the Vineland Adaptive Behavior Scale (VABS).

RESULTS

VABS scores were within normal range in 90% of the cases. There was no significant statistical difference between the study group and the control group. In addition, there was no statistically significant difference between fetuses reclassified as normal callosal length according to CC length/EFW ratio in comparison to the control group.

CONCLUSION

The neurodevelopmental outcome of fetuses with diagnosed short CC did not differ from the neurodevelopment of normal fetuses in the control group.

The Combined Use of Ultrasound and Fetal Magnetic Resonance Imaging for a Comprehensive Fetal Neurological Assessment in Fetal Congenital Cardiac Defects: Scientific Impact Paper No. 60

Heart problems are common in newborn babies, affecting approximately 5-10 in 1000 babies. Some are more serious than others, but most babies born with heart problems do not have other health issues. Of those babies who have a serious heart problem, almost 1 in 4 will have heart surgery in their first year. In the UK, pregnant women are offered a scan at around 20 weeks to try and spot any heart problems. In most cases there is not a clear reason for the problem, but sometimes other issues, such as genetic conditions, are discovered. In recent years the care given to these babies after they are born has improved their chances of surviving. However, it is recognised that babies born with heart problems have a risk of delays in their learning and development. This may be due to their medical condition, or as a result of surgery and complications after birth. In babies with heart problems, there is a need for more research on ultrasound and magnetic resonance imaging (MRI) to understand how the brain develops and why these babies are more likely to have delays in learning and development. This paper discusses the way ultrasound and MRI are used in assessing the baby's brain. Ultrasound is often used to spot any problems, looking at how the baby's brain develops in pregnancy. Advances in ultrasound technologies have made this easier. MRI is well-established and safe in pregnancy, and if problems in the brain have been seen on ultrasound, MRI may be used to look at these problems in more detail. While it is not always clear what unusual MRI findings can mean for the baby in the long term, increased understanding may mean parents can be given more information about possible outcomes for the baby and may help to improve the counselling they are offered before their baby's birth.

Congenital central nervous system anomalies: Ten-year single center experience on a challenging issue in perinatal medicine

Objective:

Our goal was to highlight the prenatal diagnosis and management of central nervous system (CNS) anomalies through sharing our clinic’s experience.

Material and Methods:

We evaluated prenatal findings and postnatal outcomes of neonates who had a CNS anomaly diagnosis in our clinic over a ten-year period. A total of 183 cases with various CNS anomalies were included in the study. Birth or termination preferences of mothers were recorded in all cases, and postnatal diagnosis concordance and prognosis after surgical procedures were evaluated in mothers who chose to continue the pregnancy.

Results:

The mean maternal age was 28.2±5.5 years, mean gravida was 2.2±1.3, and the mean gestational age at diagnosis was 30.5±5.5 weeks. Seventy-five out of 183 (41%) patients chose to terminate their pregnancy. Twenty babies (26.6%) in the termination of pregnancy group had additional anomalies. One hundred eight patients gave birth at our institution. The mean birth weight was 3060±647.5 g, the mean gestational week at delivery was 37.9±1.7 weeks, and mean APGAR score (5th minute) was 8.8±2.3. Four neonates died on the postpartum first day. The postnatal diagnosis of 60 of the 108 (55.5%) patients who gave birth was concordant with the prenatal diagnosis, and 32 of the 108 (29.6%) babies underwent surgical interventions.

Conclusion:

CNS anomalies have a broad spectrum and variable prognoses. This study highlights the limitations of prenatal diagnoses, and the need for parents to have this information in order to determine the course of their pregnancy and prepare themselves for the postnatal challenging treatment/rehabilitation process.

Prevalence and associated factors for agenesis of corpus callosum in Emilia Romagna (1981-2015)

Agenesis and hypoplasia of the corpus callosum (ACC and HCC) are heterogeneous group with a large variation in published prevalence based on few population based studies. The aim of this work is to describe prevalence, associated factors and other malformations present in cases with either agenesis or hypoplasia of the corpus callosum, using a population-based database of all malformations diagnosed in Emilia-Romagna, Italy, (the Emilia-Romagna Registry on Congenital Malformations, IMER). This registry links and integrates hospital discharge records, birth certificates with cases reported by referral clinicians to identify all structural malformations diagnosed within one year of life regarding live birth, fetal death or termination of pregnancy due to fetal malformations (TOPFA). During the study period (1981-2015) the number of cases with ACC or HCC was 255, in a reference population of 1,023,784 live births, giving an overall prevalence of 2.49 per 10,000 (1.47 per 10,000 only live birth). After 1996, with the inclusion of TOPFA in IMER registry, the overall prevalence rate increase significantly from 1.42 to 3.03 cases per 10,000 birth (p-value<0.001). Prenatal diagnosis was made in 192 cases (75.3%), at a median gestational age of 20.7 [IQR: 19.71-22.71]. Termination of pregnancy occurred in 105 of the 255 cases (41,2%). Where a prenatal diagnosis was available, 55% of cases ended in TOPFA (105/192), with higher prevalence of cases associated to central nervous system malformations and multiple birth defects, and median gestational age at diagnosis significantly less than in live birth cases (20.3 vs 29 weeks). Agenesis/hypoplasia ratio was 5.7 (217/38). The most frequently associated malformations were musculoskeletal. Trisomies were the most frequent chromosomal anomalies, in particularly trisomy18 and 13 (respectively 9/32 and 4/32 cases). Our study showed an increased risk for male infants (RR of 1.68, RR 95% CI 1.19-2.37). No differences were detected analyzing maternal age and ethnicity, and the increased risk associated to preterm birth disappeared when compared with other malformed infants. This is one of the few population based studies dealing with prevalence of agenesis and hypoplasia of corpus callosum. Prevalence is still debated, but this study adds comprehensive data, in particular inclusion of TOPFA cases. Early prenatal diagnosis, not always possible, could be crucial for decision making regarding continuation of pregnancy.

Neurodevelopmental outcome in prenatally diagnosed isolated agenesis of the corpus callosum

Neurodevelopmental outcome in children with agenesis of the corpus callosum (ACC) is correlated with the presence or absence of associated brain abnormalities. Indeed, neurodevelopmental outcome shows severe disabilities when the ACC is not isolated whereas in isolated forms, the neurologic development is mainly normal. Contrary to data in several published studies, the prognosis remains uncertain even in isolated forms, which may lead in France to medical termination of pregnancy.

OBJECTIVE

To evaluate long-term neurodevelopmental outcome in children with prenatally diagnosed isolated ACC.

DESIGN, SETTING AND PARTICIPANTS

This is a follow-up study conducted in Normandy (France). It included a cohort of 25 children born between January 1991 and June 2016, with a prenatal diagnosis of isolated ACC and who were followed for at least two years.

RESULTS

The average follow-up was 8±5years. ACC was complete in 17 patients (68%), partial in 5 (20%) and hypoplastic in 3 (12%). Whereas global motor development was normal in each case, normal neurodevelopmental outcome or mild disabilities occurred in 88% children and moderate/severe neuro-disabilities were present in 12% of children. Wechsler Intelligence Scale for Children-IV evaluations and Intellectual Total Quotients were within normal range, but we observed lower scores in verbal comprehension, social judgment, executive functions. A lower score in morphosyntax was observed among 52% of children with oral language disorders.

CONCLUSIONS

Neurodevelopmental outcome was favorable in most of our patients with isolated ACC, but mild learning disabilities emerged in older children. Long-term follow-up until school age is essential to provide early diagnosis and appropriate care support.

Anatomical subgroup analysis of the MERIDIAN cohort: failed commissuration

OBJECTIVE

To assess the contribution of fetal magnetic resonance imaging (MRI) in fetuses of the MERIDIAN cohort diagnosed with either agenesis or hypogenesis of the corpus callosum (referred to collectively as failed commissuration) on antenatal ultrasound.

METHODS

This was a subgroup analysis of the MERIDIAN study of fetuses with failed commissuration (with or without ventriculomegaly) diagnosed on ultrasound in women who had MRI assessment within 2 weeks of ultrasound and for whom outcome reference data were available. The diagnostic accuracy of ultrasound and MRI was studied, as well as indicators of diagnostic confidence and effects on prognosis/clinical management. Appropriate diagnostic confidence was assessed by the score-based weighted average method, which combines diagnostic accuracy with diagnostic confidence data.

RESULTS

In the MERIDIAN cohort, 79 fetuses were diagnosed with failed commissuration on ultrasound (55 with agenesis and 24 with hypogenesis of the corpus callosum). The diagnostic accuracy for detecting failed commissuration was 34.2% for ultrasound and 94.9% for MRI (difference, 60.7% (95% CI, 47.6-73.9%), P < 0.0001). The diagnostic accuracy for detecting hypogenesis of the corpus callosum as a discrete entity was 8.3% for ultrasound and 87.5% for MRI, and for detecting agenesis of the corpus callosum as a distinct entity was 40.0% for ultrasound and 92.7% for MRI. There was a statistically significant improvement in 'appropriate' diagnostic confidence when using MRI as assessed by the score-based weighted average method (P < 0.0001). Prognostic information given to the women changed in 36/79 (45.6%) cases after MRI and its overall effect on clinical management was 'significant', 'major' or 'decisive' in 35/79 cases (44.3%).

CONCLUSIONS

Our data suggest that any woman whose fetus has failed commissuration as the only intracranial finding detected on ultrasound should have MRI examination for further evaluation. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Clinical applications of 3D volume MR imaging of the fetal brain in utero

OBJECTIVE

In our earlier publication, we described the methods of acquiring 3D volume MR data in second and third trimester fetuses and provided normative data from a large cohort of normal fetuses. In this article, we show the applicability of the technique by describing five fetuses with a range of developmental brain abnormalities.

METHODS

The five cases described in this report all had an intra-cranial abnormality recognised on prenatal ultrasonography, which precipitated referral for in utero MR imaging. This consisted of routine ultrafast 2D sequences and 3D volume imaging acquired using balanced steady-state imaging (Fast Imaging Employing Steady-state Imaging - FIESTA). The 3D data were used to reconstruct models of the fetal brains and hence derive representations of the surfaces of the brain and estimates of volumes of the intracranial compartments.

CASE STUDIES

These cases show several important features of relevance for diagnosing intracranial fetal pathology.

CONCLUSIONS

3D volume in utero MR imaging appears to be a promising method in the prenatal assessment of the fetal brain. We propose possible areas of future research that are required to assess the techniques potential to have clinical impact. © 2017 John Wiley & Sons, Ltd.

Clinical outcomes and neurodevelopmental outcome of prenatally diagnosed agenesis of corpus callosum in single center of Korea

Objective

With recent advances and frequent use of prenatal ultrasound, the antenatal diagnosis of agenesis of the corpus callosum (ACC) is not rare in obstetrics practices. However, information regarding the long-term neurological outcome remains uncertain. The aim of this study was to investigate clinical outcomes of prenatally diagnosed ACC and to analyze postnatal neurodevelopmental outcomes of ACC neonates born in our single center.

Methods

We retrospectively reviewed 56 cases of prenatally suspected ACC referred to our center.

Results

Fifty-six fetuses were diagnosed with ACC, and 12 of those were followed-up in our center until delivery. Of the remaining 44, 7 were delivered after being referred back to the original hospital, 23 were lost to follow-up, and 14 had unknown outcomes. Among all 56, 29 were considered to have isolated ACC and 27 were considered to have non-isolated ACC. Of the 10 live fetuses delivered in our center, four had isolated ACC, three had non-isolated ACC, and the rest had outcomes unrelated to ACC. Neurodevelopmental outcome was followed-up until approximately age 3 years. Of the four with isolated ACC, three (75%) had normal neurodevelopmental outcomes.

Conclusion

Similar to other studies, the results of our single-center study included positive neurodevelopmental outcomes for those with isolated ACC. However, despite our endeavor to counsel patients with prenatally diagnosed ACC, the delivery rate in our center was quite low. Therefore, larger, multicenter, retrospective studies including long-term neurological development outcomes are crucial and urgently needed to provide better counseling.

The assessment of fetal brain growth in diabetic pregnancy using in utero magnetic resonance imaging

AIM

To assess fetal brain growth over the third trimester in pregnant women with diabetes using in utero magnetic resonance imaging (iuMRI) to determine if greater brain growth occurs in type 1 (T1DM) when compared to gestational (GDM) diabetes mellitus.

MATERIALS AND METHODS

Each consented participant was scanned at three fixed times during the third trimester using iuMRI. One hundred and fifty-seven patients were approached, 48 participants were recruited, and 36 complete data sets were analysed. Three-dimensional (3D) iuMRI volume data sets were manually segmented using software to construct models of the fetal brain from which brain volumes could be calculated. Inter-rater analysis was performed, and volume differences and growth rates were compared between T1DM and GDM.

RESULTS

Recruitment proved difficult with low uptake and high attrition rates (77.1%). Inter-rater analysis revealed excellent correlation (intraclass correlation coefficient=0.93, p<0.001) and agreement with no significant difference between operators (p=0.194). There was no evidence of increased brain volume in the T1DM group. Growth rates between visit 1 and 3 for T1DM and GDM were not significantly different (p=0.095).

CONCLUSION

T1DM brain volumes were not significantly larger than GDM volumes and there was no significant divergence of brain growth over the third trimester. Constructing volume models from 3D iuMRI acquisitions is a novel technique that can be used to assess fetal brain growth. No specialist software or knowledge is required. Larger studies attempting to recruit pregnant women in the later stages of pregnancy should employ multicentre recruitment to overcome recruitment difficulties and high attrition rates.

Findings and differential diagnosis of fetal intracranial haemorrhage and fetal ischaemic brain injury: what is the role of fetal MRI?

Ventriculomegaly (VM) is a non-specific finding on fetal imaging. Identification of the specific aetiology is important, as it affects prognosis and may even change the course of current or future pregnancies. In this review, we will focus on the application of fetal MRI to demonstrate intracranial haemorrhage and ischaemic brain injury as opposed to other causes of VM. MRI is able to identify the specific aetiology of VM with much more sensitivity and specificity than ultrasound and should be considered whenever VM is identified on obstetric ultrasound. Advances in both fetal and neonatal MRI have the potential to shed further light on mechanisms of brain injury and the impact of chronic hypoxia; such information may guide future interventions.

Analysis of supratentorial cystic abnormalities using in utero MR imaging

OBJECTIVE

Our anecdotal experience from foetal neuroimaging studies suggests that there are often significant disagreements between the findings of ultrasonography (USS) and in utero MR (iuMR) imaging in cases of antenatally detected supratentorial extra-axial cysts. Although this is a relatively rare clinical situation, it warrants further investigation because of the high risk of other intracranial abnormalities that are likely to cause long-term neurodevelopmental problems.

METHODS

We reviewed 957 consecutive referrals for iuMR of the foetal brain over a 3.5-year period and studied all cases where the referral from USS described supratentorial extra-axial cysts in the foetus. The iuMR imaging was reviewed, and a comparison between the results of the two examinations was made.

RESULTS

Supratentorial extra-axial cysts were an unusual referral for iuMR occurring in only 13/957 (1.4%) of cases. The findings on USS and iuMR imaging were conflicting in all 13 cases with intracranial pathology being excluded on iuMR imaging in 4 cases and more significant pathology being shown in 9 cases. Abnormalities of the corpus callosum were recognized in association with a cyst in eight cases, and this was recognized in only two cases on USS. Six of those cases also had abnormalities of cortical formation.

CONCLUSION

iuMR imaging should be used in the assessment of pregnancies in which a supratentorial extra-axial cyst has been detected on USS. This is based on the improved primary diagnosis and a high rate of associated brain abnormalities not detected on USS.

ADVANCES IN KNOWLEDGE

Our retrospective observational study examines a range of foetal intracranial abnormalities which are better defined using iuMRI. This is a previously described spectrum of neurodevelopmental anomalies which we suggest would benefit from MRI.