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.

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.

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.

Cerebrospinal fluid cell count variability is a major confounding factor in external ventricular drain-associated infection surveillance diagnostics: a prospective observational study.

BACKGROUND: External ventricular drain (EVD)-related infections (EVDIs) are feared complications that are difficult to rapidly and correctly diagnose, which can lead to unnecessary treatment with broad-spectrum antibiotics. No readily available diagnostic parameters have been identified to reliably predict or identify EVDIs. Moreover, intraventricular hemorrhage is common and affect cerebrospinal fluid (CSF) cellularity. The relationship between leukocytes and erythrocytes is often used to identify suspected infection and triggers the use of antibiotics pending results of cultures, which may take days. Cell count based surveillance diagnostics assumes a homogeneous distribution of cells in the CSF. Given the intraventricular sedimentation of erythrocytes on computed tomography scans this assumption may be erroneous and could affect diagnostics. AIMS: To evaluate the consistency of cell counts in serially sampled CSF from EVDs, with and without patient repositioning, to assess the effect on infection diagnostics. METHODS: We performed a prospective single-center study where routine CSF sampling was followed by a second sample after 10 min, allocated around a standard patient repositioning, or not. Changes in absolute and pairwise cell counts and ratios were analyzed, including mixed regression models. RESULTS: Data from 51 patients and 162 paired samples were analyzed. We observed substantial changes in CSF cellularity as the result of both resampling and repositioning, with repositioning found to be an independent predictor of bidirectional cellular change. Glucose and lactate levels were affected, however clinically non-significant. No positive CSF cultures were seen during the study. Thirty percent (30%) of patients changed suspected EVDI status, as defined by the cell component of local and national guidelines, when resampling after repositioning. CONCLUSIONS: CSF cell counts are not consistent and are affected by patient movement suggesting a heterogeneity in the intraventricular space. The relationship between leukocytes and erythrocytes was less affected than absolute changes. Importantly, cell changes are found to increase with increased cellularity, often leading to changes in suspected EVDI status. Faster and more precise diagnostics are needed, and methods such as emerging next generation sequencing techniques my provide tools to more timely and accurately guide antibiotic treatment. Trial Registration NCT04736407, Clinicaltrials.gov, retrospectively registered 2nd February 2021.

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.

Prognosis of fetuses with ventriculomegaly: An observational retrospective study.

OBJECTIVE: To investigate the prognosis of fetuses with ventriculomegaly (VM). METHODS: Clinical data were collected from 234 cases of fetal VM diagnosed by ultrasound between March 2010 and July 2016. VM progression was monitored, and karyotyping and infection screening performed. Magnetic resonance imaging (MRI) was performed where increasing ventricular diameter was noted. Neonatal behavioral neurological assessment (NBNA) was carried out after birth, and Bayley Scales of Infant Development assessment at 6 months. RESULTS: The in utero outcomes of Group A were better than Group B in 173 pregnancies. Isolated VM (IVM) was associated with better prognosis than nonisolated VM (NIVM); the regression rates were 74.6% (59/79) and 52.1% (49/94), respectively (χ2 = 10.222, .006). The NBNA scores were significantly higher in Group A than Group B (χ2 = 4.231, .004), but not significantly different between IVM and NIVM. The composition ratios of both the psychomotor and mental developmental index (PDI and MDI) scores were not significantly different between Groups A and B (Z = 1.869, .062 and Z = 0.826, .409, respectively). Significant differences in in utero outcomes were observed between IVM and NIVM cases in Groups A and B. CONCLUSIONS: Fetal VM prognosis is affected by the width of ventricle, chromosome abnormalities, coexisted abnormalities, and in utero progression.

Clinical value of prenatal MRI for diagnosis of isolated ventriculomegaly and prediction of early postnatal developmental outcomes.

OBJECTIVE: To investigate the relationship of ventriculomegaly (VM) with postnatal neurological development. METHODS: Fetuses with isolated VM on MRI (n = 160; VM group) were separated into three subgroups according to lateral ventricle width: subgroup A (10.0-12.0 mm; n = 113), subgroup B (12.1-15.0 mm; n = 37), and subgroup C (>15.0 mm; n = 10). Fifty normal fetuses formed a control group. Post-delivery changes in ventricular width and neurological development were assessed with MRI/ultrasonography and the Gesell Development Schedules (GDS), respectively, at 3, 6, 12, and 18 months. RESULTS: GDS scores of subgroup A and subgroup B did not differ from that of the controls at 3 and 6 months. Subgroup B scores differed significantly from the control scores at 12 and 18 months. Subgroup C scores differed from the control scores at all-time points (all P < 0.05). In the VM group, GDS scores at 12 and 18 months were significantly different from the scores at 3 months, and the score at 18 months was significantly different from the score at 6 months (P < 0.05 for all). CONCLUSION: The milder the VM, the more likely it was to disappear or improve in the postnatal period. However, specific postnatal rehabilitation should be considered when fetal ventricular width is greater than 12.1 mm.

Genomic detection of a familial 382 Kb 6q27 deletion in a fetus with isolated severe ventriculomegaly and her affected mother.

Terminal deletions of the chromosome 6q27 region are rare genomic abnormalities, linked to specific brain malformations and other neurological phenotypes. Reported cases have variable sized genomic deletions that harbor several genes including the DLL1 and TBP. We report on an inherited 0.38 Mb terminal deletion of chromosome 6q27 in a 22-week fetus with isolated bilateral ventriculomegaly and her affected mother using microarray-based comparative genomic hybridization and fluorescent in situ hybridization (FISH). The deleted region harbors at least seven genes including DLL1 and TBP. The affected mother had a history of hydrocephalus, developmental delay, and seizures commonly associated with DLL1 and TBP 6q27 deletions. This deletion is one of the smallest reported isolated 6q27 terminal deletions. Our data provides additional evidence that haploinsufficiency of the DLL1 and TBP genes may be sufficient to cause the ventriculomegaly, seizures, and developmental delays associated with terminal 6q27 deletions, indicating a plausible role in the abnormal development of the central nervous system.

Neuroendoscopic Management of Coexisting Congenital Agenesis of Bilateral Foramen of Monro with Aqueductal Stenosis and Chiari Malformation: Case Report and Review of the Literature.

BACKGROUND: Bilateral occlusion of the foramen of Monro with aqueductal stenosis is a rare entity. Only 1 previous case has been reported in the literature. CASE DESCRIPTION: We present a 25-year-old female who presented with chronic headache of 7 years duration. Neurologic examination revealed only papilledema. Imaging showed symmetrical dilation of both lateral ventricles with mild dilation of the third ventricle and a normal fourth ventricle, suggesting occlusion of both foramina of Monro with membranous web formation in the upper part of the aqueduct. There was tonsillar herniation without syrinx. She underwent neuroendoscopic foraminoplasty, septostomy, and third ventriculostomy. The patient experienced total relief of headache and showed reduced volume of both lateral ventricles at follow-up. CONCLUSIONS: Bilateral occlusion of foramen of Monro with aqueductal stenosis and tonsillar herniation is rare cause of obstructive hydrocephalus, and can be managed effectively with neuroendoscopic procedure.

Obstructive Hydrocephalus in Newborn Due to Cerebral Atrium Diverticulum Formation: Complete Resolution After Subdural Hematoma Evacuation.

BACKGROUND: Cerebral atrium diverticula are focal enlargements of the ventricular system that may develop in the presence of persistent intracranial hypertension, but they are rarely described in cases of acute intracranial hypertension. Here we present a unique case of obstructive hydrocephalus in a newborn due to the formation of a cerebral atrium diverticulum compressing the ventricular system. CASE DISCUSSION: A preterm 38-week-old boy was born with urgent caesarian section due to severe hydrocephalus. Magnetic resonance imaging showed the presence of a subacute right subdural hematoma with secondary obstructive hydrocephalus. The cystic lesion was characterized as a right ventricular atrium diverticulum. The child underwent urgent burr-hole evacuation of the right subdural hematoma with complete regression of the obstructive hydrocephalus and right atrial diverticulum. CONCLUSION: Cerebral atrium diverticula are rare focal dilatations of the ventricular system, and their radiologic diagnosis may be challenging. Accurate diagnosis of atrial diverticula and understanding of the underlying physiopathology is mandatory to establish the appropriate operative strategy.

Neurodevelopmental outcome of fetal isolated ventricular asymmetry without dilation: a cohort study.

OBJECTIVE: Fetal isolated ventricular asymmetry (IVA) is a relatively common finding in pregnancy, but data regarding its effect on neurodevelopmental outcome are scarce and founded principally on ultrasound-based studies. The purpose of this study was to assess the neurodevelopmental outcome of IVA cases in a magnetic resonance imaging (MRI)-based study. METHODS: Cases referred for fetal brain MRI as part of the assessment of IVA without ventriculomegaly (lateral ventricular atrial diameter ≤ 10 mm), identified during routine ultrasound examination, were assessed for possible inclusion. Asymmetry was defined as a difference in width of ≥ 2 mm between the two lateral ventricles. Forty-three cases were included in the study group and compared with a control group of 94 normal cases without IVA. Children were assessed at ages 13-74 months using the Vineland-II Adaptive Behavior Scales (VABS-II). RESULTS: VABS-II scores were within normal range. There was no significant difference in composite VABS-II score between the study and control groups (106.5 vs 108.0; P = 0.454). VABS-II scores did not differ between the groups when matched for gender and age at VABS-II interview (109.6 in study group vs 107.8 in control group; P = 0.690). CONCLUSION: In cases of IVA without ventriculomegaly on MRI, neurodevelopmental test scores were normal and did not differ from cases without IVA. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Outcome of fetuses with prenatal diagnosis of isolated severe bilateral ventriculomegaly: systematic review and meta-analysis.

OBJECTIVE: To quantify from the published literature survival and neurodevelopmental outcome of fetuses with prenatally detected isolated severe bilateral ventriculomegaly. METHODS: MEDLINE, EMBASE and the Cochrane Library were searched electronically. Only cases with a prenatal diagnosis of apparently isolated severe ventriculomegaly and postnatal neurodevelopmental assessment were selected and included. Severe ventriculomegaly was defined as enlargement of the ventricular atria, with a diameter of greater than 15 mm in the transventricular plane. All cases in which the investigators were unable to detect associated structural abnormality, chromosomal abnormality or fetal infection, and in which the ventriculomegaly was therefore regarded as apparently isolated, were included. Those for which the etiology was identified prenatally were excluded, whereas those with postnatal identification of the underlying cause were not excluded, since this information was not available prenatally. The quality of the included studies was assessed using the Newcastle-Ottawa Scale (NOS) for cohort studies. Pregnancy outcomes such as termination, stillbirth, neonatal survival and developmental outcome of the baby, were recorded. The degree of disability was classified as no, mild or severe disability. Statistical assessment was performed by meta-analysis of proportions to combine data, weighting the studies using the inverse variance method and a random-effects model. Proportions and CIs were reported. RESULTS: Eleven studies including 137 fetuses were found. Twenty-seven pregnancies underwent termination and were excluded. The remaining 110 fetuses with apparently isolated severe ventriculomegaly for which continuation of pregnancy was intended, form the study population. Overall quality assessed using NOS for cohort studies was good. Survival was reported in 95/110 (pooled proportion 87.9% (95% CI, 75.6-96.2%)) cases. In 15/110 (pooled proportion 12.1% (95% CI, 3.8-24.4%)), either stillbirth or neonatal demise was reported. No disability was reported in 41/95 survivors (pooled proportion 42.2% (95% CI, 27.5-57.6%)). However, 17/95 showed mild/moderate disability (pooled proportion 18.6% (95% CI, 7.2-33.8%)) and 37/95 were reported to have severe disability (pooled proportion 39.6% (95% CI, 30.0-50.0%)). CONCLUSIONS: Four-fifths of fetuses with severe ventriculomegaly survive and, of these, just over two-fifths show normal neurodevelopment. The overall survivors without disability account for more than one third of the total. Given that many cases undergo termination of pregnancy and require longer follow-up in order to detect subtle abnormalities, mortality and prevalence of developmental delay may be even higher than that reported in this paper. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Single-Shot Version of FLAIR Sequence in the Detection of Intraventricular Anomalies: Preliminary Experience in Fetal MR Imaging.

OBJECTIVE: To evaluate single-shot (ss) FLAIR sequence in the detection of intraventricular anomalies in a series of fetuses showing mild-moderate ventriculomegaly at ultrasound. SUBJECTS AND METHODS: Fetuses with mild-moderate isolated ventriculomegaly, which underwent MR imaging between 2003 and 2014 were considered eligible. Fetuses were examined by standard MR protocol and ss-FLAIR sequence, tailored for snapshot imaging. Two paediatric neuroradiologists evaluated MR images. RESULTS: 542 cases were selected. MR imaging was performed at mean 26 weeks of gestation. ss-FLAIR sequence detected intraventricular findings, consistent with cysts in 10 cases. In 3/10 intraventricular cysts were also evident on ss-FSE T2 and FSE T1-weighted images. In no case diffusion weighted imaging was able to detect cyst. No cyst was highlighted on ss-FSE-T2 and FSE-T1-weighted images, without being visible also on ss-FLAIR. CONCLUSION: ss-FLAIR sequence may be useful to detect intraventricular anomalies especially when fetal position or maternal obesity prevents adequate visualization by ultrasound.

Anatomical subgroup analysis of the MERIDIAN cohort: ventriculomegaly.

OBJECTIVE: To assess the contribution of fetal magnetic resonance imaging (MRI) in fetuses of the MERIDIAN cohort diagnosed with ventriculomegaly (VM) as the only abnormal intracranial finding on antenatal ultrasound. METHODS: This was a subgroup analysis of the MERIDIAN study of fetuses with only VM diagnosed on ultrasound in women who had a subsequent MRI examination within 2 weeks and for whom outcome reference data were available. The diagnostic accuracy of ultrasound and MRI was reported in relation to the severity of VM. The difference in measurements of trigone size on the two imaging methods and the clinical impact of adding MRI to the diagnostic pathway were also studied. RESULTS: In 306 fetuses with VM, ultrasound failed to detect 31 additional brain abnormalities, having an overall diagnostic accuracy of 89.9% for ultrasound, whilst MRI correctly detected 27 of the additional brain abnormalities, having a diagnostic accuracy of 98.7% (P < 0.0001). There were other brain abnormalities in 14/244 fetuses with mild VM on ultrasound (diagnostic accuracy, 94.3%) and MRI correctly diagnosed 12 of these (diagnostic accuracy, 99.2%; P = 0.0005). There was a close agreement between the size of trigones measured on ultrasound and on MRI, with categorical differences in only 16% of cases, showing that MRI did not systematically overestimate or underestimate trigone size. Complete prognostic data were available in 295/306 fetuses and the prognosis category changed after MRI in 69/295 (23.4%) cases. The overall effect of MRI on clinical management was considered to be 'significant', 'major' or 'decisive' in 76/295 (25.8%) cases. CONCLUSION: Our data suggest that a woman carrying a fetus with VM as the only intracranial finding on ultrasound should be offered an adjuvant investigation by MRI for further evaluation. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Risk factors for periventricular echodensities and outcomes in preterm infants.

OBJECTIVES: To determine the incidence, risk factors and outcomes associated with transient and/or persistent periventricular echodensities (PVED) among preterm infants. METHODS: Medical records of preterm infants born at ≤ 32 weeks gestational age (GA) with PVED and no other brain pathology were reviewed and compared to matched control infants in a case-controlled retrospective study. Neurodevelopmental outcomes at 8-24 months corrected age were documented. RESULTS: A 17.8% incidence of PVED was recorded, with the highest incidence of 30-40% recorded at 29-31 weeks GA. Study and control groups were similar for all maternal parameters and neonatal morbidities, except for a higher incidence of respiratory distress syndrome among the study group. PVED at one month of age was predicted by 5 min Apgar score < 7 [OR = 33.78 (CI 2.94-388.06, p = 0.005)]. PVED was not associated with long-term neurodevelopmental disability. CONCLUSIONS: No risk factors or specific associated morbidities were identified among preterm infants with transient PVED. PVED at one month of age was predicted by low 5 min Apgar scores, possibly suggesting different pathogenesis or timing between the groups. Long-term outcome studies are needed to determine PVED impact.

Magnetic resonance imaging based correlation analysis between calcarine sulcus development and isolated fetal ventriculomegaly.

Fetal ventriculomegaly development leads to neurological, motor, and/or cognitive impairment, and is presently diagnosed based on the width of the atrium in the lateral ventricle. But in this study, we have tried to assess the relationship between the development of calcarine sulcus and width of fetal lateral ventricles, to assess if calcarine sulcus can also be used for fetal ventriculomegaly diagnosis. We conducted a retrospective analysis of the magnetic resonance imaging (MRI) data from 45 subjects with isolated mild fetal ventriculomegaly (IMVM). The calcarine sulcus development was divided into three categories based on the depth; Grade 1 (undeveloped), Grade 2 (underdeveloped), and Grade 3 (fully developed), and its correlation with fetal ventriculomegaly was analyzed based on Spearman's partial rank correlation test. Based on this analysis, the width of left and right lateral ventricles showed significant downward trend with the calcarine sulcus maturation [undeveloped (Left 13.88 ± 2.70 mm, Right 14.27 ± 3.13 mm) â†’ underdeveloped (Left 12.95 ± 1.93 mm, Right 11.93 ± 2.24 mm) â†’ fully developed (Left 11.06 ± 2.10 mm, Right 10.42 ± 2.10 mm)] (FLeft  = 5.12, P = 0.01; FRight  = 10.72, P = 1.73 × 10-4 ). In addition, significant correlations were also observed between the width of the lateral ventricles and the maturity of the calcarine sulcus (Spearman's rank correlation coefficient; -0.47 for the left lateral ventricles and -0.56 for the right, both P < 0.001). Overall, our data indicated a negative correlation between the fetal morphological development of calcarine sulcus and the width of lateral ventricles in subjects having isolated fetal ventriculomegaly.