Fetal Ventriculomegaly

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.

Fetal and neonatal neuroimaging in twin-twin transfusion syndrome

OBJECTIVES

To describe the types of brain injury and subsequent neurodevelopmental outcome in fetuses and neonates from pregnancies with twin-twin transfusion syndrome (TTTS). Additionally, to determine risk factors for brain injury and to review the use of neuroimaging modalities in these cases.

METHODS

This was a retrospective cohort study of consecutive TTTS pregnancies treated with laser surgery in a single fetal therapy center between January 2010 and January 2020. The primary outcome was the incidence of brain injury, classified into predefined groups. Secondary outcomes included adverse outcome (perinatal mortality or neurodevelopmental impairment), risk factors for brain injury and the number of magnetic resonance imaging (MRI) scans.

RESULTS

Cranial ultrasound was performed in all 466 TTTS pregnancies and in 685/749 (91%) liveborn neonates. MRI was performed in 3% of pregnancies and 4% of neonates. Brain injury was diagnosed in 16/935 (2%) fetuses and 37/685 (5%) neonates and all predefined injury groups were represented. Four fetal and four neonatal cases of cerebellar hemorrhage were detected. Among those with brain injury, perinatal mortality occurred in 11/16 (69%) fetuses and 8/37 (22%) neonates. Follow-up was available for 29/34 (85%) long-term survivors with brain injury and the mean age at follow-up was 46 months. Neurodevelopmental impairment was present in 9/29 (31%) survivors with brain injury. Adverse outcome occurred in 28/53 (53%) TTTS individuals with brain injury. The risk of brain injury was increased after recurrent TTTS/post-laser twin anemia-polycythemia sequence (TAPS) (odds ratio (OR), 3.095 (95% CI, 1.581-6.059); P = 0.001) and lower gestational age at birth (OR per 1-week decrease in gestational age, 1.381 (95% CI, 1.238-1.541); P < 0.001).

CONCLUSIONS

Based on dedicated neurosonography and limited use of MRI, brain injury was diagnosed in 2% of fetuses and 5% of neonates with TTTS. Adverse outcome was seen in over half of cases with brain injury. Brain injury was related to recurrent TTTS/post-laser TAPS and a lower gestational age at birth. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Prenatal diagnosis and pregnancy outcomes in fetuses with ventriculomegaly

Objective

Genetic etiology plays a critical role in fetal ventriculomegaly (VM). However, the studies on chromosomal copy number variants (CNVs) in fetal VM are limited. This study aimed to investigate the chromosomal CNVs in fetuses with mild to moderate VM, and explore its genotype-phenotype correlation.

Methods

A total of 242 fetuses with mild to moderate VM detected by prenatal ultrasound were enrolled in our study from October 2018 to October 2022. All cases underwent chromosomal microarray analysis (CMA) and G-banding simultaneously. All VM cases were classified different subgroups according to the maternal age, severity, VM distribution and presence/absence of other ultrasound abnormalities. The pregnancy outcomes and health conditions after birth were followed up. We also performed a pooled analysis regarding likely pathogenic and pathogenic CNVs (LP/P CNVs) for VM.

Results

The detection rate of chromosomal abnormalities by karyotyping was 9.1% (22/242), whereas it was 16.5% (40/242) when CMA was conducted (P < 0.05). The total detection rate of chromosomal abnormalities by karyotyping and CMA was 21.1% (51/242). A 12.0% incremental yield of CMA over karyotyping was observed. The detection rate of total genetic variants in fetuses with bilateral VM was significantly higher than in fetuses with unilateral VM (30.0% vs. 16.7%, P = 0.017). No significant differences were discovered between isolated VM and non-isolated VM, or between mild and moderate VM, or between advanced maternal age (AMA) and non-AMA (all P > 0.05). 28 fetuses with VM were terminated and 214 fetuses were delivered: one presented developmental delay and one presented congenital heart disease. The VM cases with both positive CMA and karyotypic results had a higher rate of termination of pregnancy than those with either a positive CMA or karyotypic result, or both negative testing results (P < 0.001).

Conclusion

The combination of CMA and karyotyping should be adopted to improve the positive detection rate of chromosomal abnormalities for VM. The total genetic abnormalities detected using both techniques would affect the final pregnancy outcomes. LP/P CNVs at 16p11.2, 17p13, and 22q11.21 were identified as the top three chromosomal hotspots associated with VM, which would enable genetic counselors to provide more precise genetic counseling for VM pregnancies.

Genotype-phenotype correlation study of structural abnormalities in a fetal brain caused by a novel KDM4B variant

BACKGROUND

Fetal ventriculomegaly (VM), a common brain structure malformation detected during prenatal ultrasound diagnosis, is associated with an increased risk of neurodevelopmental disorders (NDDs) after birth. KDM4B encodes a lysine-specific demethylase that interacts with histone H3K23me3. Variations in KDM4B are reportedly associated with human NDDs; however, only 11 such patients have been reported. Herein, we report a fetus with VM and agenesis of the corpus callosum (ACC), which suggests that KDM4B plays an important role in fetal brain development.

METHODS

Fetal skin tissue and parental peripheral venous blood samples were collected. Whole-exome and Sanger sequencing were performed to analyze fetal germline variants. Human 293T cells transfected with wild-type or mutant KDM4B were used for western blotting (WB) to analyze protein expression levels.

RESULTS

An insertion variant of KDM4B, NM_015015.3: c.2889_2890insGAGAGCATCACGGTGAGCTGTGGGGTGGGGCAGGGGGCGGGGGGAGGCTGGGAGCACAGTGACAACCTGTACCCC, was identified in the fetal tissue; however, the parents carried the wild-type gene. The WB results indicated significantly reduced expression of the mutant protein, likely owing to decreased stability.

CONCLUSIONS

The structural abnormalities in the brain of the studied fetus may be attributed to an insertion variant of KDM4B. This study highlights the importance of screening for KDM4B variants and considering potential copy number variations when observing VM or ACC in prenatal ultrasound imaging.

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.

Enhancing Fetal Anomaly Detection in Ultrasonography Images: A Review of Machine Learning-Based Approaches

Fetal development is a critical phase in prenatal care, demanding the timely identification of anomalies in ultrasound images to safeguard the well-being of both the unborn child and the mother. Medical imaging has played a pivotal role in detecting fetal abnormalities and malformations. However, despite significant advances in ultrasound technology, the accurate identification of irregularities in prenatal images continues to pose considerable challenges, often necessitating substantial time and expertise from medical professionals. In this review, we go through recent developments in machine learning (ML) methods applied to fetal ultrasound images. Specifically, we focus on a range of ML algorithms employed in the context of fetal ultrasound, encompassing tasks such as image classification, object recognition, and segmentation. We highlight how these innovative approaches can enhance ultrasound-based fetal anomaly detection and provide insights for future research and clinical implementations. Furthermore, we emphasize the need for further research in this domain where future investigations can contribute to more effective ultrasound-based fetal anomaly detection.

Automatic biometry of fetal brain MRIs using deep and machine learning techniques

Linear biometric measurements on magnetic resonance images are important for the assessment of fetal brain development, which is expert knowledge dependent and laborious. This study aims to construct a segmentation-based method for automatic two-dimensional biometric measurements of fetal brain on magnetic resonance images that provides a fast and accurate measurement of fetal brain. A total of 268 volumes (5360 images) magnetic resonance images of normal fetuses were included. The automatic method involves two steps. First, the fetal brain was segmented into four parts with a deep segmentation network: cerebrum, cerebellum, and left and right lateral ventricles. Second, the measurement plane was determined, and the corresponding biometric parameters were calculated according to clinical guidelines, including cerebral biparietal diameter (CBPD), transverse cerebellar diameter (TCD), left and right atrial diameter (LAD/RAD). Pearson correlation coefficient and Bland-Altman plots were used to assess the correlation and agreement between computer-predicted values and manual measurements. Mean differences were used to evaluate the errors quantitatively. Analysis of fetal cerebral growth based on the automatic measurements was also displayed. The experiment results show that correlation coefficients for CBPD, TCD, LAD and RAD were as follows: 0.977, 0.990, 0.817, 0.719, mean differences were - 2.405 mm, - 0.008 mm, - 0.33 mm, - 0.213 mm, respectively. The correlation between the errors and gestational age was not statistically significant (p values were 0.2595, 0.0510, 0.1995, and 0.0609, respectively). The proposed automatic method for linear measurements on fetal brain MRI achieves excellent performance, which is expected to be applied in clinical practice and be helpful for prenatal diagnosis and clinical work efficiency improvement.

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.

Diagnostic yield with exome sequencing in prenatal severe bilateral ventriculomegaly: a systematic review and meta-analysis

OBJECTIVE

This study aimed to determine the incremental diagnostic yield of prenatal exome sequencing after negative chromosomal microarray analysis results in prenatally diagnosed bilateral severe ventriculomegaly or hydrocephalus; another objective was to categorize the associated genes and variants.

DATA SOURCES

A systematic search was performed to identify relevant studies published until June 2022 using 4 databases (Cochrane Library, Web of Science, Scopus, and MEDLINE).

STUDY ELIGIBILITY CRITERIA

Studies in English reporting on the diagnostic yield of exome sequencing following negative chromosomal microarray analysis results in cases of prenatally diagnosed bilateral severe ventriculomegaly were included.

METHODS

Authors of cohort studies were contacted for individual participant data, and 2 studies provided their extended cohort data. The incremental diagnostic yield of exome sequencing was assessed for pathogenic/likely pathogenic findings in cases of: (1) all severe ventriculomegaly; (2) isolated severe ventriculomegaly (as the only cranial anomaly); (3) severe ventriculomegaly with other cranial anomalies; and (4) nonisolated severe ventriculomegaly (with extracranial anomalies). To be able to identify all reported genetic associations, the systematic review portion was not limited to any minimal severe ventriculomegaly case numbers; however, for the synthetic meta-analysis, we included studies with ≥3 severe ventriculomegaly cases. Meta-analysis of proportions was done using a random-effects model. Quality assessment of the included studies was performed using the modified STARD (Standards for Reporting of Diagnostic Accuracy Studies) criteria.

RESULTS

A total of 28 studies had 1988 prenatal exome sequencing analyses performed following negative chromosomal microarray analysis results for various prenatal phenotypes; this included 138 cases with prenatal bilateral severe ventriculomegaly. We categorized 59 genetic variants in 47 genes associated with prenatal severe ventriculomegaly along with their full phenotypic description. There were 13 studies reporting on ≥3 severe ventriculomegaly cases, encompassing 117 severe ventriculomegaly cases that were included in the synthetic analysis. Of all the included cases, 45% (95% confidence interval, 30-60) had positive pathogenic/likely pathogenic exome sequencing results. The highest yield was for nonisolated cases (presence of extracranial anomalies; 54%; 95% confidence interval, 38-69), followed by severe ventriculomegaly with other cranial anomalies (38%; 95% confidence interval, 22-57) and isolated severe ventriculomegaly (35%; 95% confidence interval, 18-58).

CONCLUSION

There is an apparent incremental diagnostic yield of prenatal exome sequencing following negative chromosomal microarray analysis results in bilateral severe ventriculomegaly. Although the greatest yield was found in cases of nonisolated severe ventriculomegaly, consideration should also be given to performing exome sequencing in cases of isolated severe ventriculomegaly as the only brain anomaly identified on prenatal imaging.

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.

Perinatal management of pregnancies with Fetal Congenital Anomalies: A guide to Obstetricians and Pediatricians

Background Congenital anomalies are responsible for approximately 20% of all neonatal deaths worldwide. Improvements in antenatal screening and diagnosis have significantly improved the prenatal detection of birth defects; however, these improvements have not translated into the improved neonatal prognosis of babies born with congenital anomalies. Objectives An attempt has been made to summarise the prenatal interventions, if available, the optimal route, mode and time of delivery and discuss the minimum delivery room preparations that should be made if expecting to deliver a fetus with a congenital anomaly. Methods The recent literature related to the perinatal management of the fetus with prenatally detected common congenital anomalies were searched in English peer-reviewed journals from the PubMed database, to work out an evidence-based approach for their management. Results Fetuses with prenatally detected congenital anomalies should be delivered at a tertiary care centre with facilities for neonatal surgery and paediatric intensive care if needed. There is no indication for preterm delivery in the majority of cases. Only a few congenital malformations, like high-risk sacrococcygeal teratoma, congenital lung masses with significant fetal compromise, fetal cerebral lesions or neural tube defects with Head circumference >40 cm or the biparietal diameter is ≥12 cm, gastroschisis with extracorporeal liver, or giant omphaloceles in the fetus warrant caesarean section as the primary mode of delivery. Conclusion The prognosis of a fetus with congenital anomalies can be significantly improved if planning for delivery, including the Place and Time of delivery, is done optimally. A multi-disciplinary team should be available for the fetus to optimize conditions right from when it is born.

Fetal Brain Anatomy

"Fetal brain development has been well studied, allowing for an ample knowledge of the normal changes that occur during gestation. Imaging modalities used to evaluate the fetal central nervous system (CNS) include ultrasound and MRI. MRI is the most accurate imaging modality for parenchymal evaluation and depiction of developmental CNS anomalies. The depiction of CNS abnormalities in a fetus can only be accurately made when there is an understanding of its normal development. This article reviews the expected normal fetal brain anatomy and development during gestation. Additional anatomic structures seen on brain imaging sequences are also reviewed."

Incidence, follow-up, and postnatal clinical progress of children with central nervous system anomalies on fetal MRI

OBJECTIVE

MRI is increasingly employed to assess intrauterine fetal anomalies. Central nervous system (CNS) anomalies are common structural conditions that warrant evaluation with fetal MRI and subsequent prenatal consultation with a pediatric neurosurgeon. As the use of fetal MRI increases, there is greater impetus to understand the most common CNS structural anomalies diagnosed in utero, as well as their natural histories.

METHODS

The authors performed a single-center retrospective review of fetal MRI evaluations performed between January 2012 and December 2020. Children who underwent both prenatal and postnatal neurosurgical evaluations of CNS anomalies were included. Specific CNS anomalies on fetal MRI, associated extra-CNS findings, and suspicion for genetic abnormality or syndromes were noted. Postnatal clinical status and interventions were assessed.

RESULTS

Between January 2012 and December 2020, a total of 469 fetal MRI evaluations were performed; of these, 114 maternal-fetal pairs had CNS anomalies that warranted prenatal consultation and postnatal pediatric neurosurgical follow-up. This cohort included 67 male infants (59%), with a mean ± SD follow-up of 29.8 ± 25.0 months after birth. Fetal MRI was performed at 27.3 ± 5.8 weeks of gestational age. The most frequently reported CNS abnormalities were ventriculomegaly (57%), agenesis or thinning of the corpus callosum (33%), Dandy-Walker complex (DWC) (21%), neuronal migration disorders (18%), and abnormalities of the septum pellucidum (17%). Twenty-one children (18%) required neurosurgical intervention at a mean age of 2.4 ± 3.7 months. The most common surgical conditions included myelomeningocele, moderate to severe ventriculomegaly, encephalocele, and arachnoid cyst. Corpus callosum agenesis or thinning was associated with developmental delay (p = 0.02) and systemic anomalies (p = 0.05). The majority of prenatal patients referred for DWC had Dandy-Walker variants that did not require surgical intervention.

CONCLUSIONS

The most common conditions for prenatal neurosurgical assessment were ventriculomegaly, corpus callosum anomaly, and DWC, whereas the most common surgical conditions were myelomeningocele, hydrocephalus, and arachnoid cyst. Only 18% of prenatal neurosurgical consultations resulted in surgical intervention during infancy. The majority of referrals for prenatal mild ventriculomegaly and DWC were not associated with developmental or surgical sequelae. Patients with corpus callosum abnormalities should be concurrently referred to a neurologist for developmental assessments.

A comparison of Adult and Pediatric Hydrocephalus

Hydrocephalus is a common clinical problem encountered in neurosurgical practice. With greater subspecialisation, pediatric neurosurgery has emerged as a special discipline in several countries. However, in the developing world, which inhabits a large pediatric population, a limited number of neurosurgeons manage all types of hydrocephalus across all ages. There are some essential differences in pediatric and adult hydrocephalus. The spectrum of hydrocephalus of dysgenetic origin in a neonate and that of normal pressure hydrocephalus of the old age has a completely different strategy of management. Endoscopic third ventriculostomy outcomes are known to be closely associated with age at presentation and surgery. Efficacy of alternative pathways of CSF absorption also differs according to age. Managing this disease in various age groups is challenging because of these differences in etiopathology, tempo of the disease, modalities of investigations and various treatment protocols as well as prognosis.

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.