Neurodevelopmental outcome in isolated mild fetal ventriculomegaly: systematic review and meta-analysis

Clinical characteristics and perinatal outcome of fetuses with ventriculomegaly

PURPOSE

To assess the incidence of associated structural anomalies, chromosomal/genetic abnormalities, infections, and perinatal outcomes of fetuses with ventriculomegaly (VM), also to evaluate the role of fetal magnetic resonance imaging (MRI) in detecting associated intracranial anomalies.

METHODS

Retrospective cohort study of 149 prenatally diagnosed pregnancies with fetal VM. VM was classified as mild (Vp = 10-12 mm), moderate (Vp = 12.1-15 mm), and severe (Vp > 15 mm). Fetal MRI was performed to 97 pregnancies.

RESULTS

The incidences of an associated CNS, non-CNS, chromosomal anomaly, genetic abnormality and fetal infection were 42.3%, 11.4%, 6.1%, 2.1% and 1.3%, respectively. Fetal MRI identified additional CNS anomalies in 6.7% of cases, particularly in severe VM. The incidences of perinatal outcomes were 18.8% termination of pregnancy, 4% intrauterine and 8.1% neonatal or infant death. The rates of fetuses alive at > 12 months of age with neurological morbidity were 2.6%, 11.1% and 76.9% for mild, moderate and severe isolated VM, respectively.

CONCLUSION

The prognosis of fetuses with VM mostly depends on the severity and the associated anomalies. Mild to moderate isolated VM generally have favorable outcomes. Fetal MRI is particularly valuable in fetuses with isolated severe VM.

Volume development changes in the occipital lobe gyrus assessed by MRI in fetuses with isolated ventriculomegaly correlate with neurological development in infancy and early childhood

OBJECTIVE

This study was to systematically assess the occipital lobe gray and white matter volume of isolated ventriculomegaly (IVM) fetuses with MRI and to follow up the neurodevelopment of participants.

METHOD

MRI was used to evaluate 37 IVM fetuses and 37 control fetuses. The volume of gray and white matter in each fetal occipital gyrus was manually segmented and compared, and neurodevelopment was followed up and assessed in infancy and early childhood.

RESULT

Compared with the control group, the volume of gray matter in occipital lobe increased in the IVM group, and the incidence of neurodevelopmental delay increased.

CONCLUSION

We tested the hypothesis that prenatal diagnosis IVM represents a biological marker for development in fetal occipital lobe. Compared with the control group, the IVM group showed differences in occipital gray matter development and had a higher risk of neurodevelopmental delay.

Is choroid plexus growth altered in isolated ventriculomegaly on fetal neuro-ultrasound?

OBJECTIVES

Reveal developmental alterations in choroid plexus volume (CPV) among fetuses with isolated ventriculomegaly (VM) through neuro-ultrasound.

METHODS

This prospective study aimed to assess the development of fetal CPV in normal fetuses and those with isolated VM through neuro-ultrasound. The fetuses of isolated VM were categorized into mild, moderate, and severe groups, and subsequently, the lateral ventricle evolution was monitored. The developmental alterations in CPV among fetuses with isolated VM were determined by comparing the CPV z-scores with those of normal fetuses. Receiver operating characteristics curve analysis was used to assess the predictive value of altered CPV in lateral ventricle evolution.

RESULTS

A total of 218 normal fetuses and 114 isolated VM fetuses from 22 weeks to 35 weeks of gestation were included. The CPV decreased as the isolated VM was getting worse. Both fetuses with isolated moderate ventriculomegaly and those with isolated severe ventriculomegaly exhibited reduced CPV compared to normal fetuses. The CPV in fetuses with isolated mild ventriculomegaly (IMVM) varied, with some showing a larger CPV compared to normal fetuses, while others exhibited a smaller CPV. The larger CPV in cases of IMVM may serve as a predictive factor for either regression or stability of the lateral ventricle, while reduced CPV in cases of isolated VM may indicate worsening of the lateral ventricle.

CONCLUSION

The growth volume of fetal CP exhibited alterations in fetuses with isolated VM, and these changes were found to be correlated with the evolution of the lateral ventricle.

CLINICAL RELEVANCE STATEMENT

Neuro-ultrasound revealed varying degrees of alterations in the volume development of the choroid plexus within the fetus with isolated VM. The findings can help predict lateral ventricle prognosis, greatly contributing to prenatal diagnosis strategies for fetuses with isolated VM.

KEY POINTS

The volume of choroid plexus growth is altered in fetuses with isolated VM. The altered CPV in isolated VM was associated with lateral ventricle evolution. The findings are useful for prenatal counseling and managing fetuses with isolated VM.

Fetal Cerebral Ventriculomegaly: A Narrative Review and Practical Recommendations for Pediatric Neurologists

Fetal cerebral ventriculomegaly is one of the most common fetal neurological disorders identified prenatally by neuroimaging. The challenges in the evolving landscape of conditions like fetal cerebral ventriculomegaly involve accurate diagnosis and how best to provide prenatal counseling regarding prognosis as well as postnatal management and care of the infant. The purpose of this narrative review is to discuss the literature on fetal ventriculomegaly, including postnatal management and neurodevelopmental outcome, and to provide practice recommendations for pediatric neurologists.

Sonographic Cortical Development and Anomalies in the Fetus: A Systematic Review and Meta-Analysis

The aim of this systematic review is to report the normal cortical development of different fetal cerebral fissures on ultrasound, describe associated anomalies in fetuses with cortical malformations, and evaluate the quality of published charts of cortical fissures. The inclusion criteria were studies reporting development, anomalies, and reference charts of fetal cortical structures on ultrasound. The outcomes observed were the timing of the appearance of different cortical fissures according to different gestational age windows, associated central nervous system (CNS) and extra-CNS anomalies detected at ultrasound in fetuses with cortical malformation, and rate of fetuses with isolated anomaly. Furthermore, we performed a critical evaluation of the published reference charts for cortical development on ultrasound. Random-effect meta-analyses of proportions were used to combine the data. Twenty-seven studies (6875 fetuses) were included. Sylvian fissure was visualized on ultrasound in 97.69% (95% CI 92.0-100) of cases at 18-19, 98.17% (95% CI 94.8-99.8) at 20-21, 98.94% (95% CI 97.0-99.9) at 22-23, and in all cases from 24 weeks of gestation. Parieto-occipital fissure was visualized in 81.56% (95% CI 48.4-99.3) of cases at 18-19, 96.59% (95% CI 83.2-99.8) at 20-21, 96.85% (95% CI 88.8-100) at 22-23, and in all cases from 24 weeks of gestation, while the corresponding figures for calcarine fissure were 37.27% (95% CI 0.5-89.6), 80.42% (95% CI 50.2-98.2), 89.18% (95% CI 74.0-98.2), and 96.02% (95% CI 96.9-100). Malformations of cortical development were diagnosed as an isolated finding at ultrasound in 6.21% (95% CI 2.9-10.9) of cases, while they were associated with additional CNS anomalies in 93.79% (95% CI 89.1-97.2) of cases. These findings highlight the need for large studies specifically looking at the timing of the appearance of the different brain sulci. Standardized algorithms for prenatal assessment of fetuses at high risk of malformations of cortical development are also warranted.

Follow-up outcome analysis of 324 cases of early-onset and late-onset mild fetal ventriculomegaly: a retrospective cohort study

BACKGROUND

Mild fetal ventriculomegaly (VM) is a nonspecific finding common to several pathologies with varying prognosis and is, therefore, a challenge in fetal consultation. We aimed to perform a constant, detailed analysis of prenatal findings and postnatal outcomes in fetuses with early-onset and late-onset mild ventriculomegaly, and provide a new evidence basis and new perspective for prenatal counseling.

METHODS

This is a retrospective cohort study of women with a diagnosis of mild fetal VM between January 2018 and October 2020. The population was divided into two groups according to the gestational ages (GAs) at initial diagnosis: the early-onset group (diagnosed at/before 24+6 weeks) and the late-onset group (diagnosed after 24+6 weeks). Clinical data and pregnancy outcomes were obtained from hospital records. The children's neurodevelopment status was assessed using the Ages and Stages Questionnaire, Third Edition (ASQ-3) and telephone interviews.

RESULTS

Our study cohort comprised 324 fetuses, out of which 94 (29%) were classified as early-onset group and 230 (71%) late-onset group. Early-onset group was more likely to have concurrent additional abnormalities, whereas in the late-onset group, isolated enlargement was more common (P = 0.01). Unilateral enlargement was more common in the late-onset group (P = 0.05), and symmetrical enlargement in the early-onset group (P < 0.01). In addition, early-onset mild VM cases were more likely to have intrauterine progression (P = 0.03), and many had a higher proportion of complex multisystem abnormalities. Compared with the late-onset group, the early-onset group was more often associated with congenital brain structure malformations. Approximately 11% of fetuses with mild VM had postnatal neurodevelopmental delay/disorders, and the risk was higher in the early-onset group (19.4% vs. 7.4%). Regression analysis showed that the GA at first diagnosis, non-isolated, and intrauterine progression significantly correlated with neurodevelopmental abnormalities.

CONCLUSIONS

Early-onset and late-onset mild VM had significantly different ultrasound features and outcomes. Early-onset mild VM may have more complex potential abnormalities and are more likely to predict poor prognosis than the late-onset.

Percutaneous fetal endoscopic third ventriculostomy for severe isolated cerebral ventriculomegaly

OBJECTIVE

To demonstrate the feasibility and preliminary results of percutaneous fetal endoscopic third ventriculostomy (ETV) in human fetuses (pfETV) with isolated progressive and/or severe bilateral cerebral ventriculomegaly (IPSBV).

METHODS

The initial results of pfETV for IPSBV were described. Perioperative, perinatal and postnatal variables were described. The Ages and Stages Questionnaire (ASQ-3), 3rd edition (ASQ-3) was used for follow-up of all infants.

RESULTS

Successful pfETV was performed in 10/11 (91%) fetuses, at a median gestational age (GA) of 28.7 weeks (25.3-30.7). There were no perioperative complications. After pfETV, 70% (7/10) of the fetuses had a decreased or stabilized lateral ventricle atria|lateral ventricle's atria. The median GA at delivery was 38.2 weeks (35.9-39.3). There were no perinatal complications. The postnatal ventriculoperitoneal shunt rate was 80% (8/10). Among neonates/infants who had prenatal stabilization or a decrease in the LVAs, 4 (4/7: 57.1%) had abnormal scores on the ASQ-3. Among neonates/infants that experienced prenatal increases in the LVAs, all of them (3/3: 100%) had abnormal scores on the ASQ-3.

CONCLUSION

Percutaneous ETV is feasible in human fetuses with progressive and/or severe cerebral ventriculomegaly and seems to be a safe procedure for both the mother and the fetus.

Natural history and mid-term neurodevelopmental outcome of fetuses with isolated mild ventriculomegaly diagnosed in the second half of pregnancy

INTRODUCTION

Prenatal diagnosis and counseling of isolated ventriculomegaly (VM) represent a considerable challenge. We aimed to analyze the intrauterine evolution, associated anomalies, and neurodevelopmental outcome using the Battelle Development Inventory (BDI) of fetuses with an initial diagnosis of isolated mild VM.

MATERIAL AND METHODS

Retrospective cohort study of fetuses diagnosed with mild isolated VM (10 -12 mm) between 2012 and 2016 in a tertiary hospital. In 2018, parents were invited to complete the structured BDI test for the neurodevelopmental evaluation of their children in five domains (personal-social skills, adaptive behavior, psychomotor ability, communication, and cognition). Results exceeding two standard deviations were considered abnormal and referred to an expert neuropediatrician.

RESULTS

We identified 43 cases of mild isolated VM. In 5 (11%), structural abnormalities were detected during prenatal follow-up, being related to non-regressive forms (p = .01) and bilateral VM (p = .04). The BDI test was completed by 19/43 (44%). The global score was abnormal in 10/19 (53%). Of them, the neuropediatrician confirmed a neurodevelopmental delay solely in 3 cases that had already been diagnosed with neurological disorders. The most affected domains were gross motor skills (63%), personal-social (63%), and adaptive domains (47%). Communicative and cognitive areas were abnormal in 26% of cases.

CONCLUSION

In fetuses with isolated mild VM detected in the second half of pregnancy, 53% had an abnormal BDI test at 2-6 years, but a neurological disorder was only confirmed in the 30% of them.

Pregnancy outcomes and genetic analysis for fetal ventriculomegaly

Introduction: Fetal ventriculomegaly (VM) is associated with neurodevelopmental disorders, partly caused by genetic factor. Methods: To systematically investigate the genetic etiology of fetal VM and related pregnancy outcomes in different subgroups: IVM (isolated VM) and NIVM (non-isolated VM); unilateral and bilateral VM; mild, moderate, and severe VM, a retrospective study including 131 fetuses with VM was carried out from April 2017 to August 2022. Results: 82 cases underwent amniocentesis or cordocentesis, of whom 8 cases (9.8%) were found chromosomal abnormalities by karyotyping. Meanwhile, additional 8 cases (15.7%) with copy number variations (CNVs) were detected by copy number variation sequencing (CNV-seq). The detection rate (DR) of chromosomal abnormalities was higher in NIVM, bilateral VM and severe VM groups. And CNVs frequently occurred in NIVM, bilateral VM and moderate VM groups. In the NIVM group, the incidence of chromosomal aberrations and CNVs in multiple system anomalies (19.0%, 35.7%) was higher than that in single system anomalies (10.0%, 21.1%). After dynamic ultrasound follow-up, 124 cases were available in our cohort. 12 cases were further found other structural abnormalities, and lateral ventricular width was found increased in 8 cases and decreased in 15 cases. Meanwhile, 82 cases underwent fetal brain MRI, 10 cases of brain lesions and 11 cases of progression were additionally identified. With the involvement of a multidisciplinary team, 45 cases opted for termination of pregnancy (TOP) and 79 cases were delivered with live births. One infant death and one with developmental retardation were finally found during postnatal follow-ups. Discussion: CNV-seq combined with karyotyping could effectively improve the diagnostic rate in fetuses with VM. Meanwhile, dynamic ultrasound screening and multidisciplinary evaluation are also essential for assessing the possible outcomes of fetuses with VM.

A de novo heterozygous POU3F3 genotype for the p.(Q214*) variant in a fetus with transient isolated bilateral mild ventriculomegaly: a case report and review of the literature

The prenatal prevalence of isolated ventriculomegaly is 0.039%-0.087%. Most isolated mild ventriculomegaly (MV) fetuses (>90%) have a favorable prognosis. However, 5.6% to 7.9% of fetuses with isolated MV have adverse neurodevelopmental outcomes. In this study, we reported the first case of prenatal Snijders Blok-Fisher syndrome (OMIM: #618604) caused by a truncating variant of POU3F3 (OMIM: *602480) in a fetus with transient isolated bilateral MV. The results of karyotype analysis, chromosomal microarray analysis, and TORCH infection evaluation for the fetus were all negative. However, a de novo likely pathogenic nonsense variant of NM_006236.3 (POU3F3): c.640C > T [rs1254251078] p.(Q214*) was identified by whole-exome sequencing (WES). Despite sufficient genetic counseling, the mother refused to undertake further brain magnetic resonance imaging (MRI) and decided to keep the fetus. She gave birth to a male infant through a full-term vaginal delivery. With a long-term follow-up, the infant unfortunately gradually presented with delayed motor development. The postnatal brain MRI of the proband showed dysplasia of the corpus callosum and ventriculomegaly. Considering the high probability of misdiagnosis for such cases, we further summarized the prenatal phenotypes from 19 reported patients with variants in POU3F3. The results revealed that 14 patients displayed a normal prenatal ultrasonographic manifestation, while only approximately 26.32% of fetuses showed MV or cysts without structural deformity. Thus our findings expand the variant spectrum of POU3F3 and suggest the importance of undertaking WES and brain MRI when the fetus has isolated bilateral MV.

Hippocampal rotation is associated with ventricular atrial size

BACKGROUND

Fetal ventriculomegaly is a source of apprehension for expectant parents and may present prognostic uncertainty for physicians. Accurate prenatal counseling requires knowledge of its cause and associated findings as the differential diagnosis is broad. We have observed an association between ventriculomegaly and incomplete hippocampal inversion.

OBJECTIVE

To determine whether ventricular size is related to incomplete hippocampal inversion.

MATERIALS AND METHODS

We retrospectively evaluated pre- and postnatal brain MRIs in normal subjects (mean GA, 31 weeks; mean postnatal age, 27 days) and patients with isolated ventriculomegaly (mean GA, 31 weeks; mean postnatal age, 68 days) at a single academic medical center. Lateral ventricular diameter, multiple qualitative and quantitative markers of hippocampal inversion, and evidence of intraventricular hemorrhage were documented.

RESULTS

Incomplete hippocampal inversion and ventricular size were associated in both normal subjects (n=51) and patients with ventriculomegaly (n=32) (P<0.05). Severe ventriculomegaly was significantly associated with adverse clinical outcome in postnatal (P=0.02) but not prenatal (P=0.43) groups. In all additional cases of isolated ventriculomegaly, clinical outcome was normal over the time of assessment (mean 1±1.9 years; range 0.01 to 10 years).

CONCLUSION

Lateral ventricular atrial diameter and incomplete hippocampal inversion are associated. Less hippocampal inversion correlates with larger atria. For every 1-mm increase in fetal ventricular size, the odds of incomplete hippocampal inversion occurring increases by a factor of 1.6 in normal controls and 1.4 in patients with ventriculomegaly.

White matter changes in fetal brains with ventriculomegaly

Introduction

Ventriculomegaly (VM) is a fetal brain malformation which may present independently (isolated form) or in association with different cerebral malformations, genetic syndromes or other pathologies (non-isolated form).

Methods

This paper aims to study the effect of ventriculomegaly on the internal tridimensional architecture of fetal brains by way of Klingler's dissection. Ventriculomegaly was diagnosed using fetal ultrasonography during pregnancy and subsequently confirmed by necropsy. Taking into consideration the diameter of the lateral ventricle (measured at the level of the atrium), the brains were divided into two groups: moderate ventriculomegaly (with atrial diameter between 13 and 15 mm) and severe ventriculomegaly (with atrial diameter above 15 mm).

Results and discussion

The results of each dissection were described and illustrated, then compared with age-matched reference brains. In the pathological brains, fascicles in direct contact with the enlarged ventricles were found to be thinner and displaced inferiorly, the opening of the uncinate fasciculus was wider, the fornix was no longer in contact with the corpus callosum and the convexity of the corpus callosum was inverted. We have studied the prevalence of neurodevelopmental delay in children born with ventriculomegaly in the literature and discovered that a normal developmental outcome was found in over 90% of the mild VM cases, approximately 75% of the moderate and 60% in severe VM, with the correlated neurological impairments ranging from attention deficits to psychiatric disorders.

Diagnostic approach to fetal ventriculomegaly

Ventriculomegaly (VM) is defined as an enlargement of the lateral ventricles of the developing fetal brain. The diagnosis is easily made by measuring the lateral ventricle width at the level of the atrium, which is normally <10 mm. VM is defined as mild when the atrial width is 10-12 mm, moderate 12-15 mm, severe >15 mm. VM is a non-specific sonographic sign which is common to different pathological entities and genetic conditions. When no associated anomaly can be found VM is defined as isolated. Since the prognosis of fetal VM mainly depends on the presence of associated anomalies, a careful diagnostic approach is necessary to rule out CNS and extra- CNS fetal anomalies. Magnetic Resonance Imaging can be a useful diagnostic tool complementary to ultrasound in order to recognize subtle brain anomalies, particularly cortical disorders. In this review the diagnostic approach to fetal VM will be discussed starting from ultrasound screening, moving to neurosonographic and MRI examination and genetic evaluation, in order to recognize the cause of VM and offer the appropriate counselling to the parents.

Fetal cerebral ventriculomegaly: What do we tell the prospective parents?

Fetal cerebral ventriculomegaly is a relatively common finding, observed during approximately 1% of obstetric ultrasounds. In the second and third trimester, mild (≥10 mm) and severe ventriculomegaly (≥15 mm) are defined according to the measurement of distal lateral ventricles that is included in the routine sonographic examination of central nervous system. A detailed neurosonography and anatomy ultrasound should be performed to detect other associated anomalies in the central nervous system and in other systems, respectively. Fetal MRI might be useful when neurosonography is unavailable or suboptimal. The risk of chromosomal and non-chromosomal genetic disorders associated with ventriculomegaly is high, therefore invasive genetic testing, including microarray, is recommended. Screening for prenatal infections, in particular cytomegalovirus and toxoplasmosis, should also be carried out at diagnosis. The prognosis is determined by the severity of ventriculomegaly and/or by the presence of co-existing abnormalities. Fetal ventriculoamniotic shunting in progressive isolated severe ventriculomegaly is an experimental procedure. After delivery, ventricular-peritoneal shunting or ventriculostomy are the two available options to treat hydrocephalus in specific conditions with similar long-term outcomes. A multidisciplinary fetal neurology team, including perinatologists, geneticists, pediatric neurologists, neuroradiologists and neurosurgeons, can provide parents with the most thorough prenatal counseling. This review outlines the latest evidence on diagnosis and management of pregnancies complicated by fetal cerebral ventriculomegaly.

Prenatal findings and associated survival rates in fetal ventriculomegaly: A prospective observational study

OBJECTIVES

Fetal ventriculomegaly is associated with varying degrees of genetic and structural abnormalities. The objective was to present the experience of fetal ventriculomegaly in a large European center in relation to: 1. grade of ventriculomegaly; 2. additional chromosomal/structural abnormalities; and 3. perinatal survival rates.

METHODS

This was a prospective observational study of patients referred with fetal ventriculomegaly from January 2011 to July 2020. Data were obtained from the hospital database and analyzed to determine the rate of isolated ventriculomegaly, associated structural abnormalities, chromosomal/genetic abnormalities, and survival rates. Data were stratified into three groups; mild (Vp = 10-12 mm), moderate (Vp = 13-15 mm) and severe (Vp > 15 mm) ventriculomegaly.

RESULTS

There were 213 fetuses included for analysis. Of these 42.7% had mild ventriculomegaly, 44.6% severe and 12.7% had moderate ventriculomegaly. Initial ultrasound assessment reported isolated ventriculomegaly in 45.5% fetuses, with additional structural abnormalities in 54.5%. The rate of chromosomal/genetic abnormalities was high,16.4%. After all investigations, the true rate of isolated VM was 36.1%. The overall survival was 85.6%. Survival was higher for those with isolated VM across all groups (P < 0.05).

CONCLUSION

Ventriculomegaly is a complex condition and patients should be counselled that even with apparently isolated VM, there remains the possibility of additional genetic and/or structural problems being diagnosed in up to 10% of fetuses.

Study on the Effect of B-Ultrasound NT Scan in Early Pregnancy Combined with Serum Screening in Early and Middle Pregnancy for Down Syndrome

Objective

Down syndrome (DS), also known as trisomy 21 syndrome, is a common and most harmful congenital chromosomal genetic disease. This study is aimed at exploring the effect of B-ultrasound NT scan in early pregnancy combined with serum screening in early and middle pregnancy for Down syndrome.

Methods

A total of 168 pregnant women who were diagnosed and treated in the obstetric clinic of our hospital from January 2019 to December 2021 were selected as the research objects. B-ultrasound NT scanning and serum detection in the early and middle trimester of pregnancy were performed, respectively. The accuracy of single detection and combined detection was analyzed and compared with the results of amniotic fluid cell chromosome examination as the gold standard.

Results

There were 4 cases of DS and 165 cases of non-DS. The serum PAPP-A, AFP, and UE levels in DS group were lower than those in non-DS group. β-HCG level and NT value were higher than those in non-DS group (all p < 0.05). Among 168 pregnant women, 5 cases were diagnosed as abnormal by ultrasonography, and 1 case was diagnosed as normal. By serological test, 20 cases with high risk of DS were diagnosed in 4 cases, and 148 cases with low risk of DS were diagnosed in 2 cases. Among 168 cases examined by serology combined with ultrasound, 10 cases with high risk of DS were found, and 4 cases were diagnosed; 158 cases had low risk of DS, and 0 cases were diagnosed. The negative predictive value, specificity, and coincidence rate of DS screening by the three methods were higher, and the positive predictive value and coincidence rate of combined screening were the highest (p < 0.05). The screening risk of Down syndrome was correlated with pregnancy outcome. The abnormal pregnancy rate in high-risk group was significantly higher than that in low-risk group, and the difference was statistically significant (p < 0.05). ROC curve showed that the sensitivity, specificity, and AUC of the combined detection were greater than those of serology and NT.

Conclusion

The application of B-ultrasound NT scan in early pregnancy combined with early and mid-term serum comprehensive screening in the screening of Down's infants is helpful to improve the diagnostic coincidence rate and reduce the occurrence of misdiagnosis.

Assessment of foetal ventriculomegaly from prenatal to early postnatal period: a single-centre retrospective cohort study

The aim of this study was to evaluate the early neonatal outcomes of cases with foetal ventriculomegaly (VM) and to investigate the aetiological and prognostic factors according to the degree of VM in a single tertiary referring centre. The medical records of 87 foetuses diagnosed with VM (≥10 mm) within 6 years were evaluated. Postnatal evaluation and early neonatal prognosis were determined in 39 cases divided into two groups as mild (10-15 mm, 30 cases) and severe (>15 mm, 9 cases) according to the ventricular size. The mean gestational age at which foetal VM was detected was 22 + 3 weeks. In terms of severity, severe cases of VM were more frequent in terminated pregnancies. There was no difference in gestational age, birth weight, fifth minute Apgar scores, or cord blood gases between mild and severe cases at delivery. Isolated VM was detected in 63% of mild and 22% of severe cases. In severe cases, the need for intensive care and surgery was higher than in mild cases. Antenatal VM regressed in 50% of mild cases and 22% of severe cases. Increasing knowledge about neonatal prognosis, the factors involved in aetiology, and the degree of VM will guide the management of foetal VM.IMPACT STATEMENTWhat is already known in this subject? Some cases of foetal VM resolve spontaneously, and postnatal ultrasonography can detect normal ventricle sizes. While 74.6% of isolated VM cases show spontaneous regression, this rate is 52.1% in nonisolated cases. The gestational week at the time of diagnosis, the degree and cause of VM, intrauterine progression and the presence of any genetic, infectious, cerebral, or extracerebral disorders all influence the prognosis.What do the results of this study add? Antenatal VM regressed in 50% of mild cases and 22% of severe cases. In severe cases, the need for intensive care and surgery was higher than in mild cases. The higher frequency of accompanying cerebral findings in severe cases was striking.What are the implications of these findings for clinical practice and/or further research? The current study revealed that isolated VM with ventricular diameter less than 15 mm, after excluding out chromosomal abnormalities and prenatal infections, and no prior history of VM, has a favourable neonatal prognosis in terms of mortality and morbidity. In cases of foetal VM, increased knowledge of neonatal prognosis will guide pregnancy care and postnatal follow-up planning. Prospective multicentre studies on the neonatal period are required to bridge the gap between foetal VM and long-term consequences.

Predicting neurodevelopmental outcomes in fetuses with isolated mild ventriculomegaly

BACKGROUND

Fetal ventriculomegaly is the the most common intracranial abnormality detected antenatally. When ventriculomegaly is mild and the only, isolated, abnormality detected (isolated mild ventriculomegaly (IMVM)) the prognosis is generally considered to be good. We aim to determine if there are features on in utero MRI (iuMRI) that can identify fetuses with IMVM who have lower risks of abnormal neurodevelopment outcome.

METHODS

We studied cases recruited into the MRI to enhance the diagnosis of fetal developmental brain abnormalities in utero (MERIDIAN) study, specifically those with: confirmed IMVM, 3D volume imaging of the fetal brain and neurodevelopmental outcomes at 3 years. We explored the influence of sex of the fetus, laterality of the ventriculomegaly and intracranial compartmental volumes in relation to neurodevelopmental outcome.

FINDINGS

Forty-two fetuses met the criteria (33 male and 9 female). There was no obvious correlation between fetal sex and the risk of poor neurodevelopmental outcome. Unilateral IMVM was present in 23 fetuses and bilateral IMVM in 19 fetuses. All fetuses with unilateral IMVM had normal neurodevelopmental outcomes, while only 12/19 with bilateral IMVM had normal neurodevelopmental outcomes. There was no obvious correlation between measure of intracranial volumes and risk of abnormal developmental outcomes.

INTERPRETATION

The most important finding is the very high chance of a good neurodevelopmental outcome observed in fetuses with unilateral IMVM, which is a potentially important finding for antenatal counselling. There does not appear to be a link between the volume of the ventricular system or brain volume and the risk of poor neurodevelopmental outcome.

Fetal Brain Development: Regulating Processes and Related Malformations

This paper describes the contemporary state of knowledge regarding processes that regulate normal development of the embryonic–fetal central nervous system (CNS). The processes are described according to the developmental timetable: dorsal induction, ventral induction, neurogenesis, neuronal migration, post-migration neuronal development, and cortical organization. We review the current literature on CNS malformations associated with these regulating processes. We specifically address neural tube defects, holoprosencephaly, malformations of cortical development (including microcephaly, megalencephaly, lissencephaly, cobblestone malformations, gray matter heterotopia, and polymicrogyria), disorders of the corpus callosum, and posterior fossa malformations. Fetal ventriculomegaly, which frequently accompanies these disorders, is also reviewed. Each malformation is described with reference to the etiology, genetic causes, prenatal sonographic imaging, associated anomalies, differential diagnosis, complimentary diagnostic studies, clinical interventions, neurodevelopmental outcome, and life quality.

Clinical significance of soft markers in second trimesterr ultrasonography for pregnant Korean women: a multicenter study and literature review

Objective

To evaluate the clinical significance of soft markers for aneuploidy screening in Korean women.

Methods

We retrospectively reviewed the medical records of 5,428 singleton pregnant women who underwent sonography during the second trimester at seven institutions in South Korea. We evaluated the prevalence of the following soft markers: intracardiac echogenic focus, choroid plexus cysts, pyelectasis, echogenic bowel, and mild ventriculomegaly. We developed best-fitted regression equations for the fetal femur and humerus length using our data and defined a short femur and humerus as both long bones below the fifth centile. The results of genetic testing and postnatal outcomes were investigated in patients who had been diagnosed with aforementioned soft markers.

Results

The median maternal age of our study population was 33 years, and the median gestational age at the time of ultrasonographic examination was 21 weeks. We detected soft markers in 10.0% (n=540) of fetuses: 9.3% (n=504) were isolated cases and 0.7% (n=36) of cases had two or more markers. We identified only two aneuploides (trisomy 18, 46,XX,t[8;10][q22.1;p13]), of which one was clinically significant. We presented the neonatal outcomes of the fetuses with the respective soft markers. Preterm delivery, low birth weight, and small-for-gestational-age (SGA) were significantly more common in women with a shortened fetal femur (P<0.001, all). However, the presence of a shortened fetal humerus was not associated with those outcomes excluding SGA.

Conclusion

Soft markers in second-trimester ultrasonography have limited use in screening for fetal aneuploidy in Korean women. However, these markers can be used as a screening tool for adverse outcomes other than chromosomal abnormality.

Antenatal counselling for prospective parents whose fetus has a neurological anomaly: part 2, risks of adverse outcome in common anomalies

After diagnosis of a fetal neurological anomaly, prospective parents want to know the best and worst-case scenarios and an estimation of the risk to their infant of having an atypical developmental outcome. The literature on developmental outcomes for fetal neurological anomalies is poor: studies are characterized by retrospective design, small sample size, often no standardized assessment of development, and differing definitions of anomalies. This review provides an aide-memoir on the risks of adverse neurodevelopmental outcome for ventriculomegaly, cortical anomalies, microcephaly, macrocephaly, agenesis of the corpus callosum, posterior fossa anomalies, and myelomeningocele, to assist healthcare professionals in counselling. The data in this review should be used alongside recommendations on counselling and service design described in part 1 to provide antenatal counselling.

Prenatal work-up, associated anomalies and postnatal outcomes of foetuses with 9-9.9 mm cerebral ventricular atria width

OBJECTIVE

To analyse prenatal work-up, associated anomalies and postnatal outcomes of foetuses with cerebral lateral ventricular width 9-9.9 mm.

METHOD

This retrospective, observational, case-control study included 121 foetuses with initial presentation of isolated cerebral lateral ventricular width 9-9.9 mm detected during routine ultrasound scans, 21-24 weeks' gestation, in a tertiary referral centre, January 2001-December 2018. Controls included 123 foetuses with lateral ventricular width <9 mm measured under the same parameters. Clinical characteristics, obstetrical history, ultrasound findings, prenatal work-up and pregnancy outcomes were collected from medical records. Information about postnatal functional and neurodevelopmental sequelae were obtained from telephone-based questionnaires.

RESULTS

The study group had more males (82/116 (70.6%) versus 65/123 (52.8%), p = 0.004), more prenatal testing, including brain magnetic resonance imaging (28/116 (24.1%) versus 0/123 (0%), p < 0.001), echocardiography (46/116 (39.7%) versus 15/123 (12.2%), p < 0.001) and targeted anomaly scans (102/116 (87.9%) versus 1/123 (0.008%), p < 0.001). Long-term follow-up did not reveal more neurodevelopmental sequelae compared to controls. Gender-based analysis found more males with ventricular dilatation 9-9.9 mm treated for developmental delay compared to females with similar findings (15/82 (18.2%) versus 1/34 (2.9%), p = 0.010).

CONCLUSION

Foetuses with 9-9.9 mm cerebral lateral ventricular width versus <9 mm underwent more prenatal testing but had similar rates of neurodevelopmental sequelae.

Severe fetal ventriculomegaly: Fetal morbidity and mortality, caesarean delivery rates and obstetrical challenges in a large prospective cohort

INTRODUCTION

Severe fetal ventriculomegaly (VM) is defined as an enlargement of the atria of the lateral cerebral ventricles (Vp) of greater than 15 mm. While it is well established that it confers significant risk of morbidity and mortality to the neonate, there is limited information pertaining to the caesarean delivery rates and the obstetric management of these complex cases. The aim of this study was twofold: firstly, to determine survival rates in fetuses with severe VM, and secondly to determine the caesarean delivery rates in continuing pregnancies. We explore the obstetric challenges associated with these difficult cases.

METHODS

This was a prospective observational study of patients with antenatal severe VM, attending the Department of Fetal Medicine, National Maternity Hospital, Dublin, Ireland, from 1st January 2011 to 31st July 2020. Data were obtained from the hospital database and those with severe VM (Vp > 15 mm) were identified. The rates of chromosomal abnormalities, the survival rates and the caesarean delivery (CD) rates for the overall group were then determined. The data were then further sub-divided into two groups: 1. Vp < 20 mm and 2. Vp > 20 mm, and the results compared. Statistical analysis was performed using the Chi-Square test.

RESULTS

A total of N = 95 pregnancies with severe VM were included for analysis, of which additional structural abnormalities on ultrasound were apparent in 67/95 (70.5%) and 28/95 (29.5%) had isolated severe VM. Chromosomal abnormalities were diagnosed in 15/95 (15.8%) of cases, with (2/28) 7.1% in the isolated SVM group versus (13/67) 19.4% in the non-isolated SVM group. The overall survival rate (excluding TOP) was 53/74 (71.6%), with 20/23 (86.9%) in the isolated SVM group. The overall CD rate was 47/72 (65.3%), which was significantly higher than the CD for the hospital during the same time period of 25.4% (P < 0.01). The data were subdivided into Vp < 20 and Vp > 20 and those with a Vp > 20 had higher rates of additional intracranial findings on ultrasound (Vp < 20 13/41 (31.7%) versus Vp > 20 32/54 (59.3%) (P < 0.05)) and macrocrania (Vp < 20 14/41 (34.1%) versus Vp > 20 35/54 (64.8%) (P < 0.05)). No significant difference was observed in the overall survival or CD rates between the two groups.

CONCLUSION

In conclusion this study reports significant fetal morbidity and mortality with severe VM with high CD rates observed in this cohort. Significant challenges exist in relation to the obstetric management and counseling of parents regarding an often uncertain neonatal prognosis. In continuing pregnancies with significant macrocrania delivery plans should be individualized to improve neonatal outcomes where possible and minimize harm to the mother.

Role of prenatal magnetic resonance imaging in fetuses with isolated severe ventriculomegaly at neurosonography: A multicenter study

OBJECTIVE

The aim of this study was to report the rate of additional anomalies detected exclusively at prenatal magnetic resonance imaging (MRI) in fetuses with isolated severe ventriculomegaly undergoing neurosonography.

METHOD

Multicenter, retrospective, cohort study involving 20 referral fetal medicine centers in Italy, United Kingdom, Spain and Denmark. Inclusion criteria were fetuses affected by isolated severe ventriculomegaly (≥15 mm), defined as ventriculomegaly with normal karyotype and no other additional central nervous system (CNS) and extra-CNS anomalies on ultrasound. In all cases, a multiplanar assessment of fetal brain as suggested by ISUOG guidelines on fetal neurosonography had been performed. The primary outcome was the rate of additional CNS anomalies detected exclusively at fetal MRI within two weeks from neurosonography. Subgroup analyses according to gestational age at MRI (<vs ≥ 24 weeks of gestation) and the laterality of ventriculomegaly (unilateral vs bilateral) were also performed. Univariate and multivariate logistic regression analysis was used to analyze the data.

RESULTS

187 fetuses with a prenatal diagnosis of isolated severe ventriculomegaly on neurosonography were included in the analysis. Additional structural anomalies were detected exclusively at prenatal MRI in 18.1% of cases. When considering the type of anomaly, malformations of cortical development were detected on MRI in 32.4% cases, while midline or acquired (hypoxemic/hemorrhagic) lesions were detected in 26.5% and 14.7% of cases, respectively. There was no difference in the rate of additional anomalies when stratifying the analysis according to either gestational age at MRI or laterality of the lesion. At multivariate logistic regression analysis, the presence of additional anomalies only found at MRI was significantly higher in bilateral compared versus unilateral ventriculomegaly (OR: 4.37, 95% CI 1.21-15.76; p = 0.04), while neither maternal body mass index, age, severity of ventricular dilatation, interval between ultrasound and MRI, nor gestational age at MRI were associated with the likelihood of detecting associated anomalies at MRI.

CONCLUSION

The rate of associated anomalies detected exclusively at prenatal MRI in fetuses with isolated severe ventriculomegaly is lower than previously reported, but higher compared to isolated mild and moderate ventriculomegaly. Fetal MRI should be considered as a part of the prenatal assessment of fetuses presenting with isolated severe ventriculomegaly at neurosonography.

Prenatal Ventriculomegaly - Diagnosis, Prognostication and Management

Fetal ventriculomegaly (VM) refers to the abnormal enlargement of one or more ventricles of the brain in-utero. The enlargement may or may not be related to ventricular obstruction and increased intracranial pressure; therefore, the term "hydrocephalus" is not used. VM is diagnosed usually in the mid-trimester when the atrial diameter (AD) of the lateral ventricle is more than 10 mm on one or both sides. A thorough workup is then required to identify the cause as the etiology is diverse. Fetal magnetic resonance imaging (MRI) may yield additional information. Serial ultrasound follow-up would be required to assess its progression with advancing gestation. The prognosis and long-term outcomes greatly depend upon the etiology, the severity at diagnosis, progression, and associations. This article reviews the definitions, diagnosis, and workup of fetal VM, discusses follow-up protocols and prognosis, and examines the role of fetal therapy, including fetoscopic surgery in its prenatal management.

The Term Newborn: Postnatal Screening and Testing

Prenatal genetic screening, including evaluation for inherited genetic disorders, aneuploidy risk assessment, and sonographic assessment, combined with a thorough newborn examination and standard newborn screening, including blood, hearing, and congenital heart disease screening, can reveal conditions requiring further evaluation after delivery. Abnormal prenatal or newborn screening results should prompt additional diagnostic testing guided by maternal fetal medicine, perinatal genetics, or pediatric specialists.

Classifying and Evaluating Fetuses With Ventriculomegaly in Genetic Etiologic Studies

The association between genetics and fetuses with ventriculomegaly (VM) is unknown. This study aimed to classify and evaluate abnormal copy number variations (CNVs) in fetuses with VM. From December 2016 to September 2020, amniotic fluid or umbilical cord blood from 293 pregnant women carrying fetuses with VM was extracted for single-nucleotide polymorphism microarray (SNP array). Among 293 fetuses with VM, 31 were detected with abnormal CNVs, including 22 with pathogenic CNVs (7.51%) and nine with variation of uncertain clinical significance (VUS) CNVs (3.07%). Of the 22 fetuses with pathogenic CNVs, 13 had known disease syndromes. Among the 293 fetuses, 133 had mild isolated VM [pathogenic CNVs, 7/133 (5.26%)]; 142 had mild non-isolated VM [pathogenic CNVs, 13/142 (9.15%)]; 12 had severe isolated VM [pathogenic CNVs, 2/12 (16.67%)]; and six had severe non-isolated VM (no abnormal CNVs was detected). There was no statistical significance in the rate of pathogenic CNVs among the four groups (P = 0.326, P > 0.05). Among the 267 fetuses with successful follow-up, 38 were terminated (of these, 21 had pathogenic CNVs). Of the 229 fetuses, two had developmental delay and the remaining 227 had a good prognosis after birth. Overall, the results are useful for the detection of fetal microdeletion/microduplication syndrome and for the accurate assessment of fetal prognosis in prenatal consultation.

The added value of third trimester fetal brain MRI in cases of isolated ventriculomegaly

OBJECTIVES

To assess the added value of third trimester fetal brain MRI, performed in one tertiary referral center, in cases of isolated ventriculomegaly as established by a dedicated multiplanar neurosonography.

METHODS

Fetal brain MRI scans performed in a single tertiary center during a 3-year period were assessed for possible inclusion. Only cases diagnosed with ventriculomegaly without additional findings in a neurosonography preceding the MRI were included. Fetal MRI was performed at a median gestational of 32 weeks (IQR 31-34 weeks).

RESULTS

A total of 68 cases met the inclusion criteria. Of them, in four cases MRI identified additional findings including three cases of intraventricular hemorrhage and one case of cortical infarction. The overall rate of MRI-findings in the study population was (5.9%, 95% CI 2.3-14.2%). No additional findings were detected in cases of mild ventriculomegaly, 6.1% in moderate and 25% in severe ventriculomegaly. The combined rate of additional findings in mild to moderate ventriculomegaly was 3.3% (95%CI 0.9-11.4%).

CONCLUSIONS

MRI was able to detect additional findings in 5.9% of cases with seemingly isolated ventriculomegaly after a dedicated neurosonography. The severity of ventriculomegaly is associated with a higher chance of detecting abnormalities in fetal brain MRI.

Neurodevelopmental outcomes in mild and moderate isolated ventriculomegaly originating in utero

OBJECTIVE

To determine the differences in outcomes between mild and moderate isolated ventriculomegaly (IVM).

METHODS

We conducted a prospective cohort study on 94 fetuses with IVM and evaluated the neurodevelopmental outcomes at 12 months of age using the ASQ-3 and BSID-I neurodevelopmental assessment tools. Progression of VM was defined as an increase in the width of the ventricular by at least 3 mm during sequential ultrasound monitoring. The population was divided into two groups according to ventricular width: mild (10-12 mm) and moderate (12.1-15 mm), which were further evaluated for VM progression in utero separately.

RESULTS

Neurodevelopmental assessments at 12 months were the main form of evaluations. Neurodevelopmental impairment (NDI) was defined as a mental development index (MDI) or psychomotor development index (PDI) < 85. There were no significant differences in NDI values between the mild and moderate groups (p = .155). Compared with the non-in utero progression group (7.6%), the rate of NDI was significantly higher (p = .004) in the group with progression (33.3%). Using linear regression and correlation, no negative correlation was found between the maximum value of atrial diameter (AD) in utero and the PDI (r = -0.021, p = .914) or MDI (r = -0.073, p = .703) score. However, the maximum change in the AD in utero was negatively correlated with both PDI (r = -0.460, p = .011) and MDI (r=-0.422, p = .020) scores.

CONCLUSION

There were likely no differences in neurodevelopmental outcomes between mild and moderate IVM. In fetuses with mild to moderate VM, intrauterine progression may be a poor prognostic factor for neurodevelopmental outcomes.

The value of prenatal magnetic resonance imaging and postnatal follow-up using Gesell Developmental Schedules score for mild-to-moderate simple bilateral fetal ventriculomegaly

OBJECTIVE

To investigate the relationship of mild-to-moderate simple bilateral fetal ventriculomegaly with postnatal neurological development.

METHODS

Cases of simple lateral ventricular dilatation (273) were divided into bilateral mild dilatation (10.0-12.0 mm, 62), bilateral moderate dilatation (12.1-15.0 mm, 29), unilateral mild dilatation (133), and unilateral moderate dilatation (49) groups. The control group comprised 50 normal fetuses. Neurological development was assessed using Gesell Developmental Schedules (GDS) at postnatal 3, 6, 12, and 18 months.

RESULTS

At postnatal 6, 12, and 18 months, the GDS score was higher for bilateral than for unilateral dilatation (p < .05). At postnatal 3 and 6 months, the GDS score was higher for the bilateral dilatation groups than for the control group (p < .05). At postnatal 6, 12, and 18 months, the GDS score was higher for the bilateral moderate dilatation group than for the unilateral moderate dilatation group (p < .05). Further, at postnatal 3, 6, 12, and 18 months, the GDS score was higher for the bilateral moderate dilatation group than for the control group (p < .05).

CONCLUSION

At postnatal month 6, the GDS evaluation results of the bilateral dilatation groups were significantly inferior compared to those of the unilateral dilatation group.

Estimating cerebral venous oxygenation in human fetuses with ventriculomegaly using quantitative susceptibility mapping

RATIONALE AND OBJECTIVES

The goal of this study was to estimate venous blood oxygen saturation (SvO2) in the superior sagittal sinus (SSS) in fetal brains with ventriculomegaly (VM) using quantitative susceptibility mapping (QSM).

MATERIALS AND METHODS

A radiofrequency spoiled gradient echo sequence was used to evaluate data on 19 fetuses with VM (gestational age(GA): median = 29.9 weeks (range 23 to 37.3 weeks)) and 20 healthy fetuses (GA: median = 30.9 (range 22.7 to 38.7 weeks)) at 1.5 T. Susceptibility weighted images encompassing the entire fetal brain were acquired within 1 min. An iterative, geometry constraint-based thresholded k-space division algorithm was used for generating QSM data of the fetal brain. The venous oxygen saturation was calculated using the magnetic susceptibility of the SSS obtained from the QSM data. Mixed-model analysis of variance and interobserver variability assessment were used to analyze the results.

RESULTS

The median SvO2 values in the entire VM cohort as well as for second and third trimester fetuses (with interquartile range) were: 67.8% (63.2%, 73.6%), 73.1% (69.1%, 77.3%) and 63.8% (59.4%, 68.1%), respectively. The corresponding median SvO2 value in the healthy control group was: 65.3% (58.3%, 68.2%), 67.5% (61.7%, 69.2%) and 60.8% (53.6%, 68.2%), respectively. However, the difference of SvO2 between VM and control groups was not significant at the p = 0.05 level (p = 0.076). The SvO2 was found decreasing significantly with GA in the healthy control group (p < 0.05).

CONCLUSIONS

We report for the first time the estimation of cerebral SvO2 in human fetuses with VM using QSM. This measure of oxygen saturation might be beneficial in assessing and monitoring the metabolic status of the fetus in various clinical conditions.

Asymmetric cortical development and prognosis in fetuses with isolated mild fetal ventriculomegaly: an observational prospective study

BACKGROUND

Assessments of cortical development and identifying factors that may result in a poor prognosis for fetuses with isolated mild ventriculomegaly (IMVM) is a hot research topic. We aimed to perform a constant, detailed assessment of cortical development in IMVM fetuses using ultrasound and determine whether asymmetric cortical development occurred. Moreover, we aimed to estimate the prognosis of IMVM fetuses and compare the difference in the prognosis of IMVM fetuses presenting symmetric and asymmetric cortical maturation.

METHODS

IMVM was diagnosed by regular ultrasound, neurosonography and fetal MRI. Genetic and TORCH examinations were conducted to exclude common genetic abnormalities and TORCH infection of fetuses. Ultrasound examinations were conducted at an interval of 2-3 weeks to record sulcus development in IMVM fetuses using a scoring system. The neonatal behavioral neurological assessment (NBNA), the Ages and Stages Questionnaire, Third Edition (ASQ-3) and the Bayley Scales of Infant Development, First Edition (BSID-I) were performed after birth.

RESULTS

Forty fetuses with IMVM were included: twenty showed asymmetric cortical maturation and twenty showed symmetric cortical maturation. For IMVM fetuses presenting asymmetric cortical maturation, the mean gestational age (GA) at the first diagnosis of relatively delayed development was 24.23 weeks for the parieto-occipital sulcus, 24.71 weeks for the calcarine sulcus, and 26.43 weeks for the cingulate sulcus. All the sulci with delayed development underwent 'catch-up growth' and developed to the same grade as the sulci of the other hemisphere. The mean GA at which the two sides developed to the same grade was 29.40 weeks for the parieto-occipital sulcus, 29.30 weeks for the calcarine sulcus and 31.27 weeks for the cingulate sulcus. The NBNA, ASQ-3 and BSID-I scores of all patients were in the normal range.

CONCLUSIONS

IMVM fetuses may show mild asymmetric cortical maturation in the second trimester, but the relatively delayed sulci undergo 'catch-up growth'. The neurodevelopment of IMVM fetuses presenting asymmetric cortical maturation and 'catch-up growth' is not statistically significantly different from IMVM fetuses presenting symmetric cortical maturation.

Outcomes of Isolated Fetal Ventriculomegaly That Resolve In Utero

OBJECTIVE

Isolated fetal ventriculomegaly is often an incidental finding on antenatal ultrasound. It is benign in up to 90% of cases, although it can be associated with genetic, structural, and neurocognitive disorders. The literature suggests that over 40% of isolated mild ventriculomegaly will resolve in utero, but it is unclear if resolution decreases the associated risks.The aim of this study is to compare the fetal and neonatal genetic outcomes of ventriculomegaly that persists or resolves on subsequent ultrasound.

STUDY DESIGN

This is a retrospective cohort study of women diagnosed with isolated ventriculomegaly via fetal ultrasound at a tertiary referral center between 2011 and 2019. Patients were excluded if other structural anomalies were identified on ultrasound.

RESULTS

A total of 49 patients were included in the study, 19 in the resolved ventriculomegaly group and 30 in the persistent ventriculomegaly group. Women in the resolved ventriculomegaly group were more likely to be diagnosed earlier (24 vs. 28 weeks, p = 0.007). Additionally, they were more likely to have mild ventriculomegaly (63 vs. 84%, p = 0.15), and less likely to have structural neurological abnormalities diagnosed on postnatal imaging (5 vs. 17%, p = 0.384), although these were not statistically significant. Aneuploidy risk for resolved compared with persistent ventriculomegaly was similar (5 vs. 7%, p = 0.999).

CONCLUSION

This study suggests that resolution of isolated ventriculomegaly in utero may not eliminate the risk of genetic or chromosomal abnormalities in this population and may warrant inclusion as part of the counselling of these at-risk patients. Larger prospective studies are needed to confirm these findings.

KEY POINTS

· Ventriculomegaly is known to be associated with genetic and chromosomal abnormalities.. · Resolution of the ventriculomegaly in utero may not eliminate those risks.. · Patients with resolved ventriculomegaly should be offered aneuploidy screening or testing..

Correlation between mild fetal ventriculomegaly, chromosomal abnormalities, and copy number variations

BACKGROUND

Lateral ventriculomegaly is the most common abnormality of the fetal nervous system. This study investigated the incidence of chromosomal abnormalities and copy number variations (CNVs) in fetuses with mild ventriculomegaly (MV) based on various ultrasonic manifestations, identifying their corresponding features via ultrasound examination.

METHODS

A retrospective analysis was performed on ultrasound and neurosonogram (NSG) manifestations and genetic profiles of 334 cases with MV and invasive prenatal diagnosis.

RESULTS

Three hundred thirty-four cases with fetal MV were assessed via karyotyping. Further chromosomal microarray analysis (CMA) was performed in 182 cases with normal chromosome karyotypes; pathogenic chromosomal copy number variations (CNVs) were found in eight cases with a prevalence of 4.4% (8/182). In this study, the incidence rate of pathogenic abnormalities of chromosomes and CNVs was 5.7% (19/334). Based on whether lateral ventriculomegaly was complicated with other ultrasonic features, the 334 patients were divided into two groups: (1) 175 cases exhibited isolated ventriculomegaly (IVM; 52.4%, 175/334 group A) including two (1.1%, 2/175) with pathogenic chromosomal karyotype abnormalities-both trisomy 21; (2) 159 cases exhibited non-isolated ventriculomegaly (N-IVM; 47.6%, 159/334) with pathogenic chromosomal abnormalities and CNVs detected in17 cases (10.7%, 17/159). The N-IVM group was further divided into two groups: 105 cases exhibited MV with undetermined ultrasonic abnormalities (31.4%, 105/334, group B) with pathogenic chromosomal abnormalities and CNVs detected in eight cases (7.6%, 8/105); 54 cases exhibited MV with structural malformations (16.2%, 54/334, group C) of which nine cases (16.7%, 9/54) presented both pathogenic chromosomal abnormalities and CNVs, and five cases (55.6%, 5/9) were diagnosed with various cortical malformations. The pathogenicity rates of the IVM and N-IVM groups were statistically different (χ ²=14.159, p = 0.000). There were significant differences (χ²=7.992, p = 0.005) among groups A, B, and C.

CONCLUSIONS

Combinations of various ultrasonic abnormalities significantly affect the risk of pathogenic chromosomal abnormalities and CNVs in fetuses with MV. Cases involving cortical malformations require particular attention to the occurrence of pathogenic genetic abnormalities. When fetal MV is detected, a comprehensive ultrasound examination focusing on undetermined ultrasonic abnormalities is critical. Fetal NSG should be conducted to detect potential cerebral cortical malformation easily missed by routine ultrasound.

Sonographic spectrum and postnatal outcomes of early-onset versus late-onset fetal cerebral ventriculomegaly

OBJECTIVES

To review the prenatal characteristics and postnatal outcomes of Early-onset and Late-onset cerebral ventriculomegaly (VM).

METHODS

Single-center retrospective study 2013-2017; VM cases grouped into Early-onset VM (EVM; Diagnosis at/before 24 weeks) and Late-onset VM (LVM; Beyond 24 weeks). LVM cases had normal ventricle width measurement at mid-trimester scan. Infection serology, cytogenetics, MRI, sonographic follow-up, perinatal and neurodevelopmental outcomes were analyzed.

RESULTS

During the 5-year period, 64,662 women underwent an anomaly screening scan and 302 fetuses were identified with ventriculomegaly; 183 (60.6%) classified as early-onset and 119 (39.4%) LVM. The mean ventricular width was significantly higher in LVM cohort (14.1 mm vs 11.6 mm; p < .01). EVM cases were more often associated with structural anomalies (p < .05). Possible etiologies for EVM were aneuploidy and cerebral malformations like Absent Corpus Callosum, spina bifida, Dandy-Walker malformation, etc., whereas LVM followed aqueductal stenosis, hemorrhage, porencephaly, cerebral tumors, etc. Pregnancy outcomes were available for 251 cases. The pregnancy resulted in more live births in LVM group (87.4% vs 65.6%, p = < .01). Multivariate regression analysis demonstrated additional malformations (p < .0001, OR11.5 [95%CI: 4-35.2]), progression of VM (p = .004, OR 10.2 [95% CI: 2.1-52.3]) and severity of VM (OR 5.3 [95%CI: 0.8-37.7]) were significant predictors of Neurodevelopmental Impairment (NDI). Late gestation at diagnosis was more often associated with NDI (p = .063, OR2.4 [95%CI: 0.9-6.2]), although statistically insignificant.

CONCLUSIONS

EVM has a significantly different sonographic spectrum and outcomes compared to LVM. EVM is milder and associated with an increased risk of aneuploidy and structural malformations. LVM often occurs secondary to acquired brain lesions.

The normal fetal Cavum Septum Pellucidum in MR imaging - New biometric data

BACKGROUND AND PURPOSE

The cavum septum pellucidum (CSP) is an important landmark in the evaluation of the fetal neural axis. A deviation from the ultrasonic normal values may be associated with unfavorable outcomes, and a normal CSP provides reassurance of normal central forebrain development. Today, there is biometric data regarding the normal values for the width of the CSP in fetal ultrasound, but there is no such data for fetal MRI. The aim of this study was to determine the normal values for the measurements of the fetal CSP on MRI.

MATERIALS AND METHODS

We retrospectively examined 307 MRI scans of fetuses between 25 and 41 weeks gestation. Data was collected from the electronic charts of patients who underwent fetal MR imaging at a single tertiary Medical Center. The width and length of the CSP were measured in the axial plane, and the width and height were measured in the coronal plane.

RESULTS

The width and height of the CSP in fetuses tend to decrease starting from the 27th week of gestation onwards. High levels of intraobserver and interobserver agreements were calculated. The sex of the fetus does not appear to influence the biometry of the CSP.

CONCLUSION

This study provides MRI reference values for the dimensions of the CSP starting from the 25th week of gestation. Knowing the normal values for MRI could provide valuable information for researchers and in the decision-making process in patient's consultations.

Imaging of fetal ventriculomegaly

Fetal ventriculomegaly is the most common central nervous system abnormality detected by prenatal imaging. It has a high association with other anomalies. Etiologies and prognoses for fetal ventriculomegaly range from normal outcomes to significant neurodevelopmental sequelae. In this paper, we review the development, terminology, pathogenesis, imaging and prognosis of fetal ventriculomegaly.

Prenatal diagnosis of chromosomal aberrations by chromosomal microarray analysis in foetuses with ventriculomegaly

Ventriculomegaly is considered to be linked to abnormal neurodevelopment outcome. The aim of this retrospective study was to investigate the current applications of chromosomal microarray analysis (CMA) in foetuses with ventriculomegaly. A total of 548 foetuses with ventriculomegaly detected by prenatal ultrasound underwent single nucleotide polymorphism (SNP) array testing and were subjected to long-term follow-up. The overall prevalence of chromosomal aberrations was 7.30% (40/548), including 4.20% (23/548) with pathogenic/likely pathogenic copy number variants. The incidence of chromosomal aberrations was significantly higher in foetuses with bilateral ventriculomegaly than in those with unilateral ventriculomegaly (10.56% vs. 5.71%, P = 0.040), in foetuses with non-isolated ventriculomegaly than in those with isolated ventriculomegaly (12.99% vs. 2.38%, P < 0.0001), and in foetuses with severe ventriculomegaly than in those with mild-to-moderate ventriculomegaly (23.08% vs. 6.51%, P = 0.005). The outcome in foetuses with mild ventriculomegaly was significantly better than in those with moderate ventriculomegaly (95.60% vs. 84.00%, P = 0.003). Thus, CMA should be regarded as the first-tier test for prenatal diagnosis of foetal ventriculomegaly, especially in foetuses with bilateral or non-isolated ventriculomegaly. The outcome of foetuses with mild ventriculomegaly is favourable; however, there is an increased risk of neurodevelopmental disabilities in foetuses with moderate ventriculomegaly.

Role of prenatal magnetic resonance imaging in fetuses with isolated mild or moderate ventriculomegaly in the era of neurosonography: international multicenter study

OBJECTIVES

To assess the role of fetal magnetic resonance imaging (MRI) in detecting associated anomalies in fetuses presenting with mild or moderate isolated ventriculomegaly (VM) undergoing multiplanar ultrasound evaluation of the fetal brain.

METHODS

This was a multicenter, retrospective, cohort study involving 15 referral fetal medicine centers in Italy, the UK and Spain. Inclusion criteria were fetuses affected by isolated mild (ventricular atrial diameter, 10.0-11.9 mm) or moderate (ventricular atrial diameter, 12.0-14.9 mm) VM on ultrasound, defined as VM with normal karyotype and no other additional central nervous system (CNS) or extra-CNS anomalies on ultrasound, undergoing detailed assessment of the fetal brain using a multiplanar approach as suggested by the International Society of Ultrasound in Obstetrics and Gynecology guidelines for the fetal neurosonogram, followed by fetal MRI. The primary outcome of the study was to report the incidence of additional CNS anomalies detected exclusively on prenatal MRI and missed on ultrasound, while the secondary aim was to estimate the incidence of additional anomalies detected exclusively after birth and missed on prenatal imaging (ultrasound and MRI). Subgroup analysis according to gestational age at MRI (< 24 vs ≥ 24 weeks), laterality of VM (unilateral vs bilateral) and severity of dilatation (mild vs moderate VM) were also performed.

RESULTS

Five hundred and fifty-six fetuses with a prenatal diagnosis of isolated mild or moderate VM on ultrasound were included in the analysis. Additional structural anomalies were detected on prenatal MRI and missed on ultrasound in 5.4% (95% CI, 3.8-7.6%) of cases. When considering the type of anomaly, supratentorial intracranial hemorrhage was detected on MRI in 26.7% of fetuses, while polymicrogyria and lissencephaly were detected in 20.0% and 13.3% of cases, respectively. Hypoplasia of the corpus callosum was detected on MRI in 6.7% of cases, while dysgenesis was detected in 3.3%. Fetuses with an associated anomaly detected only on MRI were more likely to have moderate than mild VM (60.0% vs 17.7%; P < 0.001), while there was no significant difference in the proportion of cases with bilateral VM between the two groups (P = 0.2). Logistic regression analysis showed that lower maternal body mass index (adjusted odds ratio (aOR), 0.85 (95% CI, 0.7-0.99); P = 0.030), the presence of moderate VM (aOR, 5.8 (95% CI, 2.6-13.4); P < 0.001) and gestational age at MRI ≥ 24 weeks (aOR, 4.1 (95% CI, 1.1-15.3); P = 0.038) were associated independently with the probability of detecting an associated anomaly on MRI. Associated anomalies were detected exclusively at birth and missed on prenatal imaging in 3.8% of cases.

CONCLUSIONS

The incidence of an associated fetal anomaly missed on ultrasound and detected only on fetal MRI in fetuses with isolated mild or moderate VM undergoing neurosonography is lower than that reported previously. The large majority of these anomalies are difficult to detect on ultrasound. The findings from this study support the practice of MRI assessment in every fetus with a prenatal diagnosis of VM, although parents can be reassured of the low risk of an associated anomaly when VM is isolated on neurosonography. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Should chromosomal microarray be offered to fetuses with ultrasonographic soft markers in second trimester: A prospective cohort study and meta-analysis

OBJECTIVE

To evaluate whether chromosomal microarray (CMA) should be offered to fetuses with ultrasonographic soft markers (USMs) in the second trimester.

METHODS

A prospective cohort study and meta-analysis were conducted. In the prospective cohort study, 564 fetuses with USMs were enrolled. In the meta-analysis, eligible articles describing copy number variations in fetuses with USMs were included.

RESULTS

In the prospective cohort study, the diagnostic yields of CMA over non-invasive prenatal testing (NIPT) and karyotyping were significantly higher in fetuses with mild ventriculomegaly (MVM) than those in local control cohorts with normal ultrasound. However, the yields of CMA over NIPT and karyotyping in fetuses with other USMs were similar to controls. About ten studies, involving 405 fetuses with MVM and 1412 fetuses with other USMs, were included in the meta-analysis. The pooled diagnostic yields of CMA over NIPT and karyotyping in fetuses with MVM were 4.9% and 3.2%, respectively. In fetuses with other USMs, the yields of CMA over NIPT and karyotyping were 1.2% and 0.4%, respectively.

CONCLUSION

It is reasonable to offer CMA as a first-tier test to fetuses with MVM. However, for fetuses with other USMs, the considerations to perform CMA should not differ from pregnancies with normal ultrasound.

Prenatal genetic considerations in congenital ventriculomegaly and hydrocephalus

BACKGROUND

Fetal ventriculomegaly (VM) is a frequent finding in prenatal ultrasound. Rather than a proper diagnosis, VM is a sonographic sign, making prenatal counseling a complex and challenging undertaking. VM can range from severe pathologic processes leading to severe neurodevelopmental delay to normal variants.

DISCUSSION

A growing number of genetic conditions with different pathophysiological mechanisms, inheritance patterns, and long-term prognosis have been associated both to isolated and complex fetal VM. These include chromosomal abnormalities, copy number variants, and several single gene diseases. In this review, we describe some of the most common genetic conditions associated with fetal VM and provide a simplified diagnostic workflow for the clinician.

Not all ventriculomegaly is created equal: diagnostic overview of fetal, neonatal and pediatric ventriculomegaly

Fetal ventriculomegaly refers to a condition in which there is enlargement of the ventricular spaces, typically on prenatal ultrasound. It can be associated with other CNS or extra-CNS abnormalities, and this relationship is crucial to understand as it affects overall neonatal outcome. Isolated ventriculomegaly has been described in the literature with variable clinical outcome. Typically, outcome is based on the etiology and degree of ventriculomegaly. When associated with a pathologic condition, ventriculomegaly can be a result of hydrocephalus. While initial diagnosis is usually made on prenatal ultrasound, fetal magnetic resonance imaging is preferred to further elucidate any associated CNS malformations. In this paper, the authors aim to provide a comprehensive review of the diagnosis, associated etiologies, prognosis, and treatment options related to fetal, neonatal, and pediatric ventriculomegaly and hydrocephalus. In addition, preliminary data is provided from our institutional cohort of patients with a prenatal diagnosis of ventriculomegaly followed through the perinatal period.

Prenatal clinical manifestations in individuals with COL4A1/2 variants

BACKGROUND

Variants in the type IV collagen gene (COL4A1/2) cause early-onset cerebrovascular diseases. Most individuals are diagnosed postnatally, and the prenatal features of individuals with COL4A1/2 variants remain unclear.

METHODS

We examined COL4A1/2 in 218 individuals with suspected COL4A1/2-related brain defects. Among those arising from COL4A1/2 variants, we focused on individuals showing prenatal abnormal ultrasound findings and validated their prenatal and postnatal clinical features in detail.

RESULTS

Pathogenic COL4A1/2 variants were detected in 56 individuals (n=56/218, 25.7%) showing porencephaly (n=29), schizencephaly (n=12) and others (n=15). Thirty-four variants occurred de novo (n=34/56, 60.7%). Foetal information was available in 47 of 56 individuals, 32 of whom (n=32/47, 68.1%) had one or more foetal abnormalities. The median gestational age at the detection of initial prenatal abnormal features was 31 weeks of gestation. Only 14 individuals had specific prenatal findings that were strongly suggestive of features associated with COL4A1/2 variants. Foetal ventriculomegaly was the most common initial feature (n=20/32, 62.5%). Posterior fossa abnormalities, including Dandy-Walker malformation, were observed prenatally in four individuals. Regarding extrabrain features, foetal growth restriction was present in 16 individuals, including eight individuals with comorbid ventriculomegaly.

CONCLUSIONS

Prenatal observation of ventriculomegaly with comorbid foetal growth restriction should prompt a thorough ultrasound examination and COL4A1/2 gene testing should be considered when pathogenic variants are strongly suspected.

Prenatal detection of chromosomal abnormalities and copy number variants in fetuses with ventriculomegaly

OBJECTIVES

To systematically investigate chromosomal abnormalities and copy number variants (CNVs) in fetuses with different types of ventriculomegaly (VM) by karyotyping and/or chromosomal microarray analysis (CMA).

METHODS

This retrospective study included 312 fetuses diagnosed with VM. Amniotic fluid and umbilical blood samples were collected by amniocentesis and cordocentesis, respectively, and subjected to karyotyping and/or CMA. Subgroup analysis by VM type, including mild VM (MVM) and severe VM (SVM), unilateral and bilateral VM, isolated VM (IVM), and non-isolated VM (NIVM), was performed.

RESULTS

The detection rate of chromosomal abnormalities was 12.1% (34/281) by karyotyping and 20.6% when CMA was additionally performed (P < 0.05). Abnormalities were identified by CMA in 17.4% (38/218) of fetuses and pathogenic CNVs in 5.0% (11/218). Notably, CMA detected CNVs in 10.6% (23/218) of fetuses with normal karyotypes. The incidence of chromosomal abnormalities by karyotyping was higher in bilateral than in unilateral VM (20.5% versus 6.5%), whereas the incidence detected by CMA was higher in NIVM than in IVM (21.4% versus 10.3%; both P < 0.05). In NIVM, CMA provided an additional detection rate of 11.4% (16/140) and a detection rate of 10.0% for pathogenic CNVs and aneuploidies. Central nervous system (CNS) abnormalities were the most common other ultrasonic abnormalities.

CONCLUSIONS

CMA is highly recommended for prenatal diagnosis of fetal VM together with karyotyping, especially in fetuses with bilateral VM and NIVM with abnormal CNS findings. Further study is necessary to explore the relationships between genotypes and phenotypes to facilitate prenatal diagnosis of fetal VM.

Evaluation of Hemodynamic Changes in Fetuses With Isolated Mild-to-Moderate Ventriculomegaly by Transabdominal Ultrasound

OBJECTIVES

To investigate fetal hemodynamic alterations using transabdominal ultrasound in fetuses with isolated mild-to-moderate ventriculomegaly (VM).

METHODS

Fetuses diagnosed with isolated mild-to-moderate VM by transabdominal ultrasound were evaluated for hemodynamic changes, including changes in fetal cardiac function, the umbilical artery, the ductus venosus, and the middle cerebral artery. The fetuses with isolated mild-to-moderate VM were divided into 2 groups, namely, before 32 weeks' gestation (20 weeks-31 weeks 6 days) and after 32 weeks' gestation (32-38 weeks), and matched to corresponding healthy control fetuses.

RESULTS

The 53 fetuses with VM before 32 weeks had a longer mean isovolumetric relaxation time (IRT; mean ± SD, 42.9 ± 6.8 versus 40.4 ± 5.0 milliseconds; P < .05) and an apparently higher modified myocardial performance index 0.46 ± 0.06 versus 0.43 ± 0.05; P < .01) than the healthy control fetuses. The 43 fetuses with VM after 32 weeks had a significantly longer mean IRT (45.5 ± 6.7 versus 40.9 ± 7.2 milliseconds; P < .01) and a lower UA pulsatility index (0.81 ± 0.13 versus 0.89 ± 0.11; P < .01). The optimal cutoff levels for the IRT in the prediction of adverse perinatal outcomes were 40 and 43 milliseconds before and after 32 weeks, respectively (sensitivity, 100% versus 100%; specificity, 40.4% versus 50.0%; area under the curve, 0.601 versus 0.748; 95% confidence interval, 0.457-0.733 versus 0.590-0.869; P = .291 versus .005).

CONCLUSIONS

Some fetuses with isolated mild-to-moderate VM may have impaired cardiac function, characterized by a higher modified myocardial performance index or longer IRT. This finding might be useful for improving fetal surveillance.