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

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.

Anomalies of the Corpus Callosum in Prenatal Ultrasound: A Narrative Review for Diagnosis and Further Counseling

The corpus callosum is the major interhemispheric tract that plays an important role in neurological function. Understanding the etiology and embryology development helps the ultrasound diagnosis for disorders of the corpus callosum and further counseling. The nonvisualization of cavum septum pellucidum or dysmorphic cavum septum pellucidum in axial view are indirect signs for beginners to diagnose complete agenesis of corpus callosum (cACC) and partial agenesis of the corpus callosum (pACC). Further coronal view, sagittal view, and fetal magnetic resonance imaging are also important for evaluation. Genetic testing plays an essential tool in anomalies of corpus callosum by revealing the underlying genetic pathophysiology, such as chromosomal anomalies and numerous monogenetic disorders in 30%-45% of ACC. Diagnosis and prediction of prognosis for hypoplasia or hyperplasia of the corpus callosum are more difficult compared to cACC and pACC because of the limited reports in the literature. However, the complex types often had poorer prognostic outcomes compared to the isolated types. Hence, it is important to evaluate and follow fetal conditions thoroughly to rule out intracranial or extracranial anomalies in other systems.

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.

Fetal neuroimaging applications for diagnosis and counseling of brain anomalies: Current practice and future diagnostic strategies

Advances in fetal brain neuroimaging, especially fetal neurosonography and brain magnetic resonance imaging (MRI), allow safe and accurate anatomical assessments of fetal brain structures that serve as a foundation for prenatal diagnosis and counseling regarding fetal brain anomalies. Fetal neurosonography strategically assesses fetal brain anomalies suspected by screening ultrasound. Fetal brain MRI has unique technological features that overcome the anatomical limits of smaller fetal brain size and the unpredictable variable of intrauterine motion artifact. Recent studies of fetal brain MRI provide evidence of improved diagnostic and prognostic accuracy, beginning with prenatal diagnosis. Despite technological advances over the last several decades, the combined use of different qualitative structural biomarkers has limitations in providing an accurate prognosis. Quantitative analyses of fetal brain MRIs offer measurable imaging biomarkers that will more accurately associate with clinical outcomes. First-trimester ultrasound opens new opportunities for risk assessment and fetal brain anomaly diagnosis at the earliest time in pregnancy. This review includes a case vignette to illustrate how fetal brain MRI results interpreted by the fetal neurologist can improve diagnostic perspectives. The strength and limitations of conventional ultrasound and fetal brain MRI will be compared with recent research advances in quantitative methods to better correlate fetal neuroimaging biomarkers of neuropathology to predict functional childhood deficits. Discussion of these fetal sonogram and brain MRI advances will highlight the need for further interdisciplinary collaboration using complementary skills to continue improving clinical decision-making following precision medicine principles.

Case Report: Occlusion of the foramen of Monro treated with endoscopic septostomy and foraminotomy in a preterm neonate

Background

Hydrocephalus is a brain abnormality frequently encountered in neonates. There are several known etiologies of hydrocephalus, which can be classified as either congenital or acquired. Occlusion of the foramen of Monro (FOM) is a cause of hydrocephalus and can be either congenital or secondary to various disorders. Idiopathic obstruction of the FOM presenting as prenatal ventriculomegaly is extremely rare but has been reported.

Case presentation

We present the case of a preterm newborn with severe bilateral hydrocephalus due to FOM occlusion in the prenatal period. Although the neonate had normal head circumference and no clinical symptoms after birth, brain sonography revealed progressive ventriculomegaly. Further image revealed bilateral ventriculomegaly with normal-sized third and fourth ventricles. We suspected a complete obstruction of the right and a partial obstruction of the left of the FOM. The neonate underwent endoscopic septostomy and foraminotomy, resulting in improvement.

Conclusion

We report a case of preterm FOM occlusion in the youngest and smallest neonate to date. Endoscopic septostomy and foraminotomy were performed in order to avoid ventriculoperitoneal shunt-related complications, highlighting the viability of endoscopic procedures which should be the primary treatment in preterm neonates with FOM occlusion.

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.

Prenatal ultrasound for the diagnosis of the agenesis of corpus callosum: a meta-analysis

BACKGROUND

Prenatal ultrasound has been regularly used as the screening tool for agenesis of corpus callosum (ACC) of the fetuses, which were mainly suspected on the basis of indirect signs rather than the visualization of the CC. However, the diagnostic accuracy of prenatal ultrasound for ACC, compared to the gold standard of postmortem diagnosis or postnatal images, is still unknown. This meta-analysis was performed to comprehensively evaluate the efficacy of prenatal ultrasound for the diagnosis of ACC.

METHODS

Studies evaluating the diagnostic accuracy of prenatal ultrasound for ACC compared to postmortem diagnosis or postnatal images were retrieved by searching PubMed, Embase, and Web of Science databases. Pooled sensitivity and specificity were calculated with a random-effects model. The diagnostic accuracy was measured by summarized area under the receiver operating characteristic (AUC) curve.

RESULTS

Twelve studies involving 544 fetuses with suspected anomalies of central nervous system were included, and 143 of them were with validated diagnosis of ACC. Pooled results showed that prenatal ultrasound has satisfying diagnostic efficacy for ACC, with the pooled sensitivity, specificity, positive and negative likelihood ratios of 0.72 (95% confidence interval [CI]: 0.39-0.91), 0.98 (95% CI: 0.79-1.00), 43.73 (95% CI: 3.42-558.74, and 0.29 (95% CI: 0.11-0.74), respectively. The pooled AUC was 0.94 (95% CI: 0.92-0.96), suggesting good diagnostic performance of prenatal ultrasound. Subgroup analysis according to the prenatal ultrasound procedures showed a better diagnostic efficacy of neurosonography than that of regular ultrasound screening (sensitivity: 0.84 versus 0.57, specificity: 0.98 versus 0.89, and AUC: 0.97 versus 0.78).

CONCLUSIONS

Prenatal ultrasound, particularly for the neurosonography, confers satisfying efficacy for the diagnosis of ACC.

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

INTRODUCTION

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Use of artificial intelligence in obstetrics: not quite ready for prime time

Artificial intelligence is finding several applications in healthcare settings. This study aimed to report evidence on the effectiveness of artificial intelligence application in obstetrics. Through a narrative review of literature, we described artificial intelligence use in different obstetrical areas as follows: prenatal diagnosis, fetal heart monitoring, prediction and management of pregnancy-related complications (preeclampsia, preterm birth, gestational diabetes mellitus, and placenta accreta spectrum), and labor. Artificial intelligence seems to be a promising tool to help clinicians in daily clinical activity. The main advantages that emerged from this review are related to the reduction of inter- and intraoperator variability, time reduction of procedures, and improvement of overall diagnostic performance. However, nowadays, the diffusion of these systems in routine clinical practice raises several issues. Reported evidence is still very limited, and further studies are needed to confirm the clinical applicability of artificial intelligence. Moreover, better training of clinicians designed to use these systems should be ensured, and evidence-based guidelines regarding this topic should be produced to enhance the strengths of artificial systems and minimize their limits.

Prenatal predictors of adverse perinatal outcome in congenital cytomegalovirus infection: a retrospective multicenter study

OBJECTIVES

To identify predictors of adverse perinatal outcome in congenital cytomegalovirus (CMV) infection.

METHODS

In a multicenter study fetuses with congenital CMV infection diagnosed by PCR on amniotic fluid and normal prenatal imaging at the time of diagnosis were included. Primary outcome was the occurrence of structural anomalies at follow-up ultrasound or prenatal magnetic resonance imaging (MRI). Secondary outcomes were the occurrence of anomalies detected exclusively postnatally and the rate of symptomatic infection.

RESULTS

One hundred and four fetuses with congenital CMV were included in the study. Anomalies were detected at follow-up ultrasound or MRI in 18.3% (19/104) cases. Additional anomalies were found after birth in 11.9% (10/84) of cases and 15.5% (13/85) of newborns showed clinical symptoms related to CMV infection. There was no difference in either maternal age (p=0.3), trimester (p=0.4) of infection and prenatal therapy (p=0.4) between fetuses with or whiteout anomalies at follow-up. Conversely, median viral load in the amniotic fluid was higher in fetuses with additional anomalies at follow-up (p=0.02) compared to those without. At multivariate logistic regression analysis, high viral load in the amniotic fluid, defined as ≥100,000 copies/mL was the only independent predictor for the occurrence of anomalies detected exclusively at follow-up ultrasound assessment or MRI, with an OR of 3.12.

CONCLUSIONS

Viral load in the amniotic fluid is a strong predictor of adverse perinatal outcome in congenital CMV infection. The results of this study emphasize the importance of adequate follow up even in case of negative neurosonography to better predict postnatal adverse outcomes of infected newborns, especially in amniotic fluid high viral load.

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.

AFFIRM: Affinity Fusion-Based Framework for Iteratively Random Motion Correction of Multi-Slice Fetal Brain MRI

Multi-slice magnetic resonance images of the fetal brain are usually contaminated by severe and arbitrary fetal and maternal motion. Hence, stable and robust motion correction is necessary to reconstruct high-resolution 3D fetal brain volume for clinical diagnosis and quantitative analysis. However, the conventional registration-based correction has a limited capture range and is insufficient for detecting relatively large motions. Here, we present a novel Affinity Fusion-based Framework for Iteratively Random Motion (AFFIRM) correction of the multi-slice fetal brain MRI. It learns the sequential motion from multiple stacks of slices and integrates the features between 2D slices and reconstructed 3D volume using affinity fusion, which resembles the iterations between slice-to-volume registration and volumetric reconstruction in the regular pipeline. The method accurately estimates the motion regardless of brain orientations and outperforms other state-of-the-art learning-based methods on the simulated motion-corrupted data, with a 48.4% reduction of mean absolute error for rotation and 61.3% for displacement. We then incorporated AFFIRM into the multi-resolution slice-to-volume registration and tested it on the real-world fetal MRI scans at different gestation stages. The results indicated that adding AFFIRM to the conventional pipeline improved the success rate of fetal brain super-resolution reconstruction from 77.2% to 91.9%.

Role of fetal magnetic resonance imaging in fetuses with congenital cytomegalovirus infection: multicenter study

OBJECTIVE

To investigate the role of fetal brain magnetic resonance imaging (MRI) in detecting associated anomalies in fetuses with congenital cytomegalovirus (CMV) infection and normal neurosonography.

METHODS

This was a multicenter, retrospective cohort study of patients examined between 2012 and 2021 in 11 referral fetal medicine centers in Italy. Inclusion criteria were fetuses with congenital CMV infection diagnosed by polymerase chain reaction analysis of amniotic fluid, pregnancies that underwent detailed multiplanar ultrasound assessment of the fetal brain as recommended by the International Society of Ultrasound in Obstetrics and Gynecology, maternal age ≥ 18 years, normal fetal karyotype and MRI performed within 3 weeks after the last ultrasound examination. The primary outcome was the rate of central nervous system (CNS) anomalies detected exclusively on MRI and confirmed after birth or autopsy in fetuses with a prenatal diagnosis of congenital CMV infection and normal neurosonography at diagnosis. Additional CNS anomalies were classified into anomalies of the ventricular and the periventricular zone, intracranial calcifications in the basal ganglia or germinal matrix, destructive encephalopathy in the white matter, malformations of cortical development, midline anomalies, posterior fossa anomalies and complex brain anomalies. We evaluated the relationship between the incidence of structural CNS malformations diagnosed exclusively on fetal MRI and a number of maternal and gestational characteristics. Univariate and multivariate logistic regression analyses were used to identify and adjust for potential independent predictors of the MRI diagnosis of fetal anomalies.

RESULTS

The analysis included 95 fetuses with a prenatal diagnosis of congenital CMV infection and normal neurosonography referred for prenatal MRI. The rate of structural anomalies detected exclusively at fetal MRI was 10.5% (10/95). When considering the type of anomaly, malformations of cortical development were detected on MRI in 40.0% (4/10) of fetuses, destructive encephalopathy in 20.0% (2/10), intracranial calcifications in the germinal matrix in 10.0% (1/10) and complex CNS anomalies in 30.0% (3/10). On multivariate logistic regression analysis, only CMV viral load in the amniotic fluid, expressed as a continuous variable (odds ratio (OR), 1.16 (95% CI, 1.02-1.21); P = 0.02) or categorical variable (> 100 000 copies/mL) (OR, 12.0 (95% CI, 1.2-124.7); P = 0.04), was independently associated with the likelihood of detecting fetal anomalies on MRI. Associated anomalies were detected exclusively at birth and missed by both prenatal neurosonography and fetal MRI in 3.8% (3/80) of fetuses with congenital CMV infection.

CONCLUSIONS

Fetal brain MRI can detect additional anomalies in a significant proportion of fetuses with congenital CMV infection and negative neurosonography. Viral load in the amniotic fluid was an independent predictor of the risk of associated anomalies in these fetuses. The findings of this study support a longitudinal evaluation using fetal MRI in congenital CMV infection, even in cases with negative neurosonography at diagnosis. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Fetal Neurology: From Prenatal Counseling to Postnatal Follow-Up

Brain abnormalities detected in fetal life are being increasingly recognized. Child neurologists are often involved in fetal consultations, and specific fetal neurology training has been implemented in many countries. Pediatric neurologists are asked to examine the data available and to contribute to the definition of the long-term outcomes. Ventriculomegaly, posterior fossa malformations, and agenesis/dysgenesis of corpus callosum are among the most common reasons for antenatal neurological consultations. Fetuses with central nervous system and extra-CNS anomalies should ideally be managed in secondary/tertiary hospitals where obstetricians who are experts in fetal medicine and pediatric specialists are available. Obstetricians play a critical role in screening, performing detailed neurosonography, and referring to other specialists for additional investigations. Clinical geneticists are frequently asked to propose diagnostic tests and counsel complex fetal malformations whose phenotypes may differ from those during postnatal life. Advances in fetal MRI and genetic investigations can support the specialists involved in counseling. Nevertheless, data interpretation can be challenging, and it requires a high level of expertise in a multidisciplinary setting. Postnatally, child neurologists should be part of an integrated multidisciplinary follow-up, together with neonatologists and pediatricians. The neurodevelopmental outcomes should be assessed at least up to school age. Children should be evaluated with formal tests of their gross motor, cognitive, language, fine motor/visuo-perceptual skills, and their behavior. In this perspective, fetal neurology can be regarded as the beginning of a long journey which continues with a prolonged, structured follow-up, support to the families, and transition to adult life. A review of the most common conditions is presented, along with the long-term outcomes and a proposal of the neurodevelopmental follow-up of children with CNS malformation which are diagnosed in uterus.

Maternal blood inflammatory marker levels increased in fetuses with ventriculomegaly

Background

Fetal ventriculomegaly (VM) is one of the most common abnormalities of the central nervous system (CNS), which can be significantly identified by brain anomalies prenatally by magnetic resonance imaging (MRI). Aberrant white blood cells (WBCs) levels indicate that the maternal is suffering from the infection. Previous studies have confirmed that prenatal infection can affect fetal brain structure, but there is no research revealed the association between maternal blood parameters with fetal VM until now.

Methods

We measured the width of the lateral ventricle of 142 fetuses, which were divided into the fetal VM group (n = 70) and the normal lateral ventricle group (n = 72). We compared maternal blood cell levels between the two groups and investigate potential biomarkers of fetal VM.

Result

High levels of maternal WBC and neutrophil (NE#) levels were observed in fetuses with VM (p < 0.001), while lymphocyte percentage, monocytes (MO#), neutrophil/lymphocyte ratio (NLR), and platelet were also increased in the fetal VM group (p = 0.033, 0.027, 0.034, and 0.025, respectively). receiver-operator curve (ROC) analysis suggested that WBC and NE# counts might be useful to distinguish fetuses with enlarged lateral ventricles (AUC = 0.688, 0.678, respectively).

Conclusion

The current study emphasizes the importance of maternal infection for fetal brain growth, which could provide important information for prenatal diagnosis of CNS anomalies. Future research needs longitudinal analysis and exploration of the influence of maternal blood inflammatory marker levels on fetal brain development.

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.

Early detection of ischemic brain injuries by diffusion-weighted imaging after radiofrequency ablation for fetal reduction in monochorionic pregnancies

BACKGROUND

This study aimed to investigate the additional advantages of magnetic resonance imaging (MRI), particularly diffusion-weighted imaging (DWI) over fetal ultrasound in the detection of acute ischemic cerebral injuries in complicated monochorionic (MC) pregnancies that underwent selective reduction by radiofrequency ablation (RFA).

METHODS

This prospective cohort study was conducted on 40 women with complicated MC pregnancies who were treated by RFA. Fetal brain imaging by DWI and conventional MRI was performed either in the early (within 10 days after RFA) or late phase (after 3-6 weeks) in the surviving fetuses to detect both acute and chronic ischemic injuries. The presence of anemia after RFA was also evaluated by Doppler ultrasound.

RESULTS

Overall, 13 of the total 43 fetuses (30.23%) demonstrated MRI abnormalities with normal brain ultrasound results including germinal matrix hemorrhage (GMH), extensive cerebral ischemia, and mild ventriculomegaly. Although seven fetuses with GMH eventually survived, fetuses that demonstrated ischemic lesions and ventriculomegaly on MRI died in the uterus.

CONCLUSION

The absence of abnormal cerebral lesions or anemia on ultrasound and Doppler exams does not necessarily rule out fetal brain ischemia. Performing early MRI, particularly DWI seems to be a reasonable option for detection of early intracranial ischemic changes and better management of complicated multiple pregnancies which were treated by RFA.

Fetal corpus callosum abnormalities: Ultrasound and magnetic resonance imaging role

The corpus callosum (CC) is the major interhemispheric commissure and its abnormalities include agenesis, hypoplasia, and hyperplasia. The CC anomalies are typically related to other central nervous system (CNS) or extra-CNS malformations. The antenatal diagnosis of complete CC agenesis is easy after mid-trimester by ultrasound (US) even in the axial plane. The non-visualization of cavum septum pellucidum and colpocephaly are critical signs in the axial view. More subtle findings (i.e., hypoplasia and partial agenesis) might also be recognized antenatally. In this review, the focus was given on the prenatal diagnosis of CC abnormalities in US and magnetic resonance imaging.

Contribution of fetal magnetic resonance imaging in the evaluation of neurosonographically detected cases of isolated mild and moderate cerebral ventriculomegaly

AIM

This study aimed to present the contribution of prenatal magnetic resonance imaging (MRI) in the diagnosis of fetuses that were previously identified as isolated mild and moderate cerebral ventriculomegaly (VM) by ultrasound (US).

METHODS

The data between February 2013 and August 2020 were collected for women who were diagnosed with isolated mild or moderate fetal VM by US and subsequently underwent a fetal MRI.

RESULTS

Among 321 women, 21 (6.5%) had a clinically important additional finding after MRI. Twelve of 276 (4.3%) fetuses with mild VM and 9 of 45 (20%) with moderate VM had turned out to have additional central nervous system abnormalities. Additional findings were detected more in fetuses with moderate VM, mothers with an anterior-located placenta, and mothers with higher body mass indexes (BMIs) with statistical significance (p = 0.001, p = 0.013, p = 0.036, respectively). The most common additional MRI finding was grade 3 or 4 germinal matrix hemorrhage, which was detected in 11 of 21 fetuses (52.3%).

CONCLUSIONS

Considering the countries' health policies, prenatal MRI would contribute mostly to the diagnosis of fetuses with moderate VM, pregnancies with anterior-located placenta, and mothers with high BMIs. According to our data, we believe that MRI will be valuable, especially in the diagnosis of grade 3 and 4 intracranial hemorrhage group.

Fetal periventricular pseudocysts: is MRI evaluation needed? What is the long-term neurodevelopmental outcome? Systematic review and meta-analysis

OBJECTIVE

To explore the value of magnetic resonance imaging (MRI) in fetuses with periventricular pseudocysts (PVPC) and the neurodevelopmental outcomes of these fetuses via meta-analysis.

METHODS

MEDLINE and EMBASE database were searched for studies reporting on the MRI assessment of fetuses diagnosed with PVPC on neurosonography. The neurosonography was conducted according to the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG) guidelines or standard axial, coronal and sagittal planes for advanced central nervous system (CNS) assessment. Single-shot fast spin-echo T2-weighted sequences of MRI technique in three orthogonal planes were necessarily performed. The pooled proportion of CNS anomalies missed on neurosonography and detected only at prenatal MRI was calculated. Subanalysis was performed according to the types of intracranial anomalies. The pregnancy outcomes (including normal, abnormal, termination of pregnancy, and perinatal death) of PVPC fetuses were also analyzed.

RESULTS

Five studies comprising 136 fetuses were included in this meta-analysis. Mean gestational age was 29.8 weeks (16-38 weeks) at ultrasonography and 31.5 weeks (25-37 weeks) at MRI. Overall, MRI detected exclusively CNS anomalies in 25.2% (95% CI 15.9-35.8%) of cases. Among them, the highest incidence was white matter abnormalities with the pooled proportion of 16.3% (95% CI 9.7-24.2%). When getting rid of white matter abnormalities, the risk of associated CNS anomalies only detected on MRI was reduced to 9.1% (95% CI 1.8-21.4%). Meanwhile, 130 cases were studied to assess the pregnancy outcomes with the scope of 1 month to 10 years. The pooled proportion of normal outcomes in isolated PVPC fetuses was as high as 95.0% (95% CI 83.9-99.8%). When analyzing the neurodevelopmental outcomes in non-isolated PVPC fetuses, the incidence of normal neurodevelopmental outcomes was about 22.1% (95% CI 5.6-45.5%) with mild and single additional abnormalities, the rate of abnormal neurodevelopmental outcomes was 19.5% (95% CI 11.0-29.7%) with apparent and/or multiple abnormalities. Besides, 53.6% (95% CI 35.4-71.3%) of non-isolated PVPC cases were terminated mainly due to infections, genetic anomalies, metabolic disorders and hemorrhage.

CONCLUSIONS

MRI assessment of PVPC fetuses is recommended to detect associated intracranial anomalies that may be missed on dedicated neurosonography. White matter abnormalities on MRI account for the majority of additional anomalies, which might to be the clue of CMV infection, aminoacidopathy or white matter disease. Moreover, the neurodevelopmental outcome of isolated PVPC fetuses remains favorable, while the neurodevelopmental outcomes of non-isolated PVPC fetuses depend on the accompanying anomaly.

Fetal brain imaging: A comparison between fetal ultrasonography and intra uterine magnetic resonance imaging (a systematic review and meta-analysis)

OBJECTIVE

The aim of this study was to compare ultrasound (US) and intra uterine MRI (IUMRI) of the brain in the diagnosis of fetal brain abnormalities.

METHODS

The present systematic review is done based on guidelines for preferred reporting items for systematic reviews and meta-analysis. All major articles comparing fetal US with IUMRI in fetuses with suspected brain abnormalities were qualified. Articles published before 2010 were excluded from the study. An I²  > 20% was considered as a sign of significant change. The statistical analysis was done using STATA -15 and Meta-Disk 1.4 applications.

RESULTS

Five articles were considered for meta-analysis. The sensitivity of US and IUMRI in diagnosing fetal abnormalities were 86% and 95%, respectively. The corresponding rates for specificity were 77% and 80%. IUMRI and US were concordant in 72.5% (95% CI: 68%-77%) of diagnoses. However, IUMRI added information in 21.7% of cases, while US added value was only 1.48.

CONCLUSION

Our results approved the good diagnostic performance of both US and IUMRI in confirming fetal brain normal development and emphasized that US is an appropriate screening technique in pregnancy. In cases of detected abnormalities in US, IUMRI is suggested as it was the most accurate imaging method and added information about the diagnosis in 22.2% of cases.

Methodological quality of fetal brain structure charts for screening examination and targeted neurosonography: a systematic review

Introduction: The methodological quality of fetal brain charts has not been critically appraised yet. Material and methods: MEDLINE, EMBASE, CINAHL and the Web of Science databases were searched electronically up to December 31, 2020. The primary outcome was to evaluate the methodology of the studies assessing the growth of fetal brain structures throughout gestation. A list of 28 methodological quality criteria divided into three domains according to “study design”, “statistical and reporting methods”, and “specific relevant neurosonography aspects” was developed in order to assess the methodological appropriateness of the included studies. The overall quality score was defined as the sum of low risk of bias marks, with the range of possible scores being 0–28. This quality assessment was applied to each individual study reporting reference ranges for fetal brain structures. Results: Sixty studies were included in the systematic review. The overall mean quality score of the studies included in this review was 51.3%. When focusing on each of the assessed domains, the mean quality score was 53.7% for “study design”, 54.2% for “statistical and reporting methods” and 38.6% for “specific relevant neurosonography aspects”. The sample size calculation, the correlation with a postnatal imaging evaluation and the whole fetal brain assessment were the items at the highest risk of bias for each domain assessed, respectively. The subgroup analysis according to different anatomical location showed the lowest quality score for ventricular and periventricular structures and the highest for cortical structures. Conclusions: Most previously published studies reporting fetal brain charts suffers from poor methodology and are at high risk of biases, mostly when focusing on neurosonography issues. Further prospective longitudinal studies aiming at constructing specific growth charts for fetal brain structures should follow rigorous methodology to minimize the risk of biases, guarantee higher levels of reproducibility and improve the standard of care.

Reference ranges for fetal brain structures using magnetic resonance imaging: systematic review

OBJECTIVE

To evaluate the methodology of studies reporting reference ranges for fetal brain structures on magnetic resonance imaging (MRI).

METHODS

MEDLINE, EMBASE, CINAHL and the Web of Science databases were searched electronically up to 31 December 2020 to identify studies investigating biometry and growth of the fetal brain and reporting reference ranges for brain structures using MRI. The primary aim was to evaluate the methodology of these studies. A list of 26 quality criteria divided into three domains, including 'study design', 'statistical and reporting methods' and 'specific aspects relevant to MRI', was developed and applied to evaluate the methodological appropriateness of each of the included studies. The overall quality score of a study, ranging between 0 and 26, was defined as the sum of scores awarded for each quality criterion and expressed as a percentage (the lower the percentage, the higher the risk of bias).

RESULTS

Fifteen studies were included in this systematic review. The overall mean quality score of the studies evaluated was 48.7%. When focusing on each domain, the mean quality score was 42.0% for 'study design', 59.4% for 'statistical and reporting methods' and 33.3% for 'specific aspects relevant to MRI'. For the 'study design' domain, sample size calculation and consecutive enrolment of women were the items found to be at the highest risk of bias. For the 'statistical and reporting methods' domain, the presence of regression equations for mean and SD for each measurement, the number of measurements taken for each variable and the presence of postnatal assessment information were the items found to be at the highest risk of bias. For the 'specific aspects relevant to MRI' domain, whole fetal brain assessment was not performed in any of the included studies and was therefore considered to be the item at the highest risk of bias.

CONCLUSIONS

Most of the previously published studies reporting fetal brain reference ranges on MRI are highly heterogeneous and have low-to-moderate quality in terms of methodology, which is similar to the findings reported for ultrasound studies. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

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.

Lissencephaly: Update on diagnostics and clinical management

Lissencephaly represents a spectrum of rare malformations of cortical development including agyria, pachygyria and subcortical band heterotopia. The progress in molecular genetics has led to identification of 31 lissencephaly-associated genes with the overall diagnostic yield over 80%. In this review, we focus on clinical and molecular diagnosis of lissencephaly and summarize the current knowledge on histopathological changes and their correlation with the MRI imaging. Additionally we provide the overview of clinical follow-up recommendations and available data on epilepsy management in patients with lissencephaly.

Magnetic Resonance Imaging (MRI) Diagnosis of Fetal Corpus Callosum Abnormalities and Follow-up Analysis

OBJECTIVES

We analyzed the magnetic resonance imaging (MRI) manifestations of fetal corpus callosum abnormalities and discussed their prognosis based on the results of postnatal follow up.

METHODS

One hundred fifty-five fetuses were diagnosed with corpus callosum abnormalities by MRI at our hospital from 2004 to 2019. Gesell Development Scales were used to evaluate the prognosis of corpus callosum abnormalities after birth.

RESULTS

Corpus callosum abnormalities were diagnosed in 149 fetuses from singleton pregnancies, and 6 pairs of twins, 1 in each pair is a corpus callosum abnormality. Twenty-seven cases (27/155) were lost to follow up, whereas 128 cases (128/155) were followed up. Of these, 101 cases were induced for labor, whereas 27 cases were born naturally. Among the 27 cases of corpus callosum abnormality after birth, 22 cases were from singleton pregnancies (22/27). Moreover, 1 twin from each of 5 pairs of twins (5/27) demonstrated corpus callosum abnormalities. The average Gesell Development Scale score was 87.1 in 19 cases of agenesis of the corpus callosum and 74.9 in 3 cases of hypoplasia of the corpus callosum. Among the 5 affected twins, 2 had severe neurodevelopmental delay, 2 had mild neurodevelopmental delay, and 1 was premature and died.

CONCLUSION

The overall prognosis of agenesis of the corpus callosum is good in singleton pregnancies. Hypoplasia of the corpus callosum is often observed with other abnormalities, and the development quotient of hypoplasia of the corpus callosum is lower compared with agenesis of the corpus callosum. Corpus callosum abnormalities may occur in one twin, in whom the risk may be increased.

The Assessment of the Usefulness of Prenatal Magnetic Resonance Imaging in the Diagnosis of Central Nervous System Defects

Central nervous system (CNS) abnormalities cause about 40% of infant deaths in the first year of life. In case of the detection of abnormalities by ultrasound, a pregnant woman should be offered prenatal magnetic resonance imaging (pMRI). The aims of our study were: (1) to evaluate the effectiveness of pMRI in the diagnosis of selected fetal CNS defects; and (2) to assess the possibility of replacing postnatal tests with prenatal magnetic resonance. The prospective and observational study was conducted between 2014 and 2017 at the University Hospital in Krakow. Patients with suspected CNS defects of the fetus were qualified for pMRI in the third trimester of pregnancy. Sixty patients were included in the study group. Prenatal MRI was characterized by low accuracy in the diagnosis of complex brain defects. Cohen’s kappa coefficient κ = 0.21 (95% CI 0.00–0.46). No evidence was found suggesting the replacement of postnatal tests with pMRI. MRI was characterized by low consistency of diagnoses in the case of complex brain defects. The possibility of replacing postnatal studies with pMRI was not supported.

Prenatal diagnosis and postnatal management of congenital unilateral hydrocephalus for stenosis of the foramen of Monro

Congenital hydrocephalus and ventriculomegaly can be diagnosed reliably with prenatal ultrasound and Magnetic Resonance Imaging (MRI). Unilateral hydrocephalus is uncommon, and the prognosis depends on etiology and postnatal management. Here, we present a case of a 32-years-old woman with prenatal diagnosis of unilateral hydrocephalus associated with stenosis of the foramen of Monro. Unilateral hydrocephalus is an uncommon feature that can be detected prenatally on ultrasound and MRI. In case of isolated stenosis of the foramen of Monro prognosis is good.

Risk of neural tube defects according to maternal body mass index: a systematic review and meta-analysis

INTRODUCTION

The aim of our systematic review and meta-analysis was to evaluate the risk of neural tube defects (NTDs) according to the pre-pregnancy body mass index.

MATERIALS AND METHODS

Electronic databases were searched (MEDLINE, EMBASE, Web of Sciences, Scopus, ClinicalTrial.gov, OVID, and Cochrane Library). Selection criteria included prospective and retrospective cohort studies reporting the prevalence of fetal NTDs in obese, overweight, and underweight pregnant women. Odds ratios (ORs) comparing risk among these subsets of pregnancies with normal weight mothers were determined with 95% confidence intervals (CI). The evaluated outcome was the association between maternal underweight, overweight, and obesity and the risk of NTDs.

RESULTS

We included ten studies published between 2000 and 2017, including underweight, overweight, and obese pregnant women with fetal NTD (cases) and pregnant women with recommended BMI with fetal NTD (controls). Compared with normal BMI women, obese mothers were at significantly higher risk of fetal NTDs (0.53 vs. 0.33%; OR 1.62 95% CI 1.32-1.99, p < .0001), while no difference for the risk of NTDs was found when comparing overweight (0.34 vs. 0.32%; OR 1.09 95% CI 0.92-1.3, p = .3) and underweight (0.65 vs. 0.24%; OR 1.34 95% CI 0.73-2.47, p = .34) with normal weight pregnant women.

DISCUSSION

Obese pregnant women are at significantly higher risk NTDs, while no significant difference has been found in overweight and underweight pregnant women. Key message Obese pregnant women are at significantly higher risk of NTDs, such as spina bifida compared with normal weight women. No difference was found when comparing overweight and underweight with normal weight women.

Role of prenatal magnetic resonance imaging in fetuses with isolated anomalies of corpus callosum: multinational study

OBJECTIVE

To assess the performance of fetal magnetic resonance imaging (MRI) in detecting associated anomalies in fetuses diagnosed with isolated corpus callosal (CC) anomaly on multiplanar ultrasound evaluation of the fetal brain (neurosonography).

METHODS

This was a multicenter, retrospective cohort study involving 14 fetal medicine centers in Italy, UK, Portugal, Canada, Austria and Spain. Inclusion criteria were fetuses with an apparently isolated CC anomaly, defined as an anomaly of the CC and no other additional central nervous system (CNS) or extra-CNS abnormality detected on expert ultrasound, including multiplanar neurosonography; normal karyotype; maternal age ≥ 18 years; and gestational age at diagnosis ≥ 18 weeks. The primary outcome was the rate of additional CNS abnormalities detected exclusively on fetal MRI within 2 weeks following neurosonography. The secondary outcomes were the rate of additional abnormalities according to the type of CC abnormality (complete (cACC) or partial (pACC) agenesis of the CC) and the rate of additional anomalies detected only on postnatal imaging or at postmortem examination.

RESULTS

A total of 269 fetuses with a sonographic prenatal diagnosis of apparently isolated CC anomalies (207 with cACC and 62 with pACC) were included in the analysis. Additional structural anomalies of the CNS were detected exclusively on prenatal MRI in 11.2% (30/269) of cases, with malformations of cortical development representing the most common type of anomaly. When stratifying the analysis according to the type of CC anomaly, the rate of associated anomalies detected exclusively on MRI was 11.6% (24/207) in cACC cases and 9.7% (6/62) in pACC cases. On multivariate logistic regression analysis, only maternal body mass index was associated independently with the likelihood of detecting associated anomalies on MRI (odds ratio, 1.07 (95% CI, 1.01-1.14); P = 0.03). Associated anomalies were detected exclusively after delivery and were missed on both types of prenatal imaging in 3.9% (8/205) of fetuses with prenatal diagnosis of isolated anomaly of the CC.

CONCLUSION

In fetuses with isolated anomaly of the CC diagnosed on antenatal neurosonography, MRI can identify a small proportion of additional anomalies, mainly malformations of cortical development, which are not detected on ultrasound. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

[Prenatal ultrasound prognostic of myelomeningocele at the era of fetal surgery]

Myelomeningocele (MMC) is a severe congenital condition responsible for motor and sensory impairments of the lower limbs, incontinence and cognitive impairment. Its screening, sometimes as early as the first trimester, is one of the major goals of modern prenatal care, supported by the emergence of prenatal surgery that results in a significant improvement in motor function, ambulation and ventriculoperitoneal shunt rate in patients undergoing in-utero surgery. From screening to pre- and post-operative prognostic evaluation, prenatal ultrasound is now an essential tool in the antenatal management of this condition. Using the multi planar and three-dimensional modes, it can be used to assess the vertebral level of MMC, which remains the key antenatal prognostic marker for motor function and ambulation, incontinence and the need for a ventriculo-peritoneal shunt. A careful and systematic ultrasound examination also makes it possible to assess the severity and progression of ventriculomegaly, to search for associated cerebral, spinal cord or vertebral anomalies, or to rule out exclusion criteria for in-utero surgery such as severe kyphosis or serious cortical anomalies. New tools from post-natal evaluation, such as the "metameric" ultrasound assessment of lower limb mobility, appear to be promising either for the initial examination or after in-utero surgery. Ultrasonography, associated with fetal MRI, cytogenetic and next generation sequencing, now allows a highly customized prognostic evaluation of these fetuses affected by MMC and provides the parents with the best possible information on the expected benefits and limitations of fetal surgery.

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.

Outcome of fetuses with congenital cytomegalovirus infection and normal ultrasound at diagnosis: systematic review and meta-analysis

OBJECTIVE

To report the outcome of fetuses with congenital cytomegalovirus (CMV) infection and normal ultrasound at the time of diagnosis, and to evaluate the rate of an additional anomaly detected only on magnetic resonance imaging (MRI).

METHODS

Medline, EMBASE, CINAHL and Cochrane databases were searched for studies reporting on the outcome of fetuses with congenital CMV infection. Inclusion criteria were fetuses with confirmed CMV infection and normal ultrasound assessment at the time of the initial evaluation. The outcomes observed were an anomaly detected on a follow-up ultrasound scan, an anomaly detected on prenatal MRI but missed on ultrasound, an anomaly detected on postnatal assessment but missed prenatally, perinatal mortality, symptomatic infection at birth, neurodevelopmental outcome and hearing and visual deficits. Neurodevelopmental outcome was assessed only in cases of isolated CMV infection confirmed at birth. Subgroup analysis was performed according to the trimester in which maternal infection occurred. Random-effects meta-analysis of proportions was used to analyze the data.

RESULTS

Twenty-six studies were included, comprising 2603 fetuses with congenital CMV infection, of which 1178 (45.3%) had normal ultrasound at the time of diagnosis and were included in the analysis. The overall rate of an associated central nervous system (CNS) anomaly detected on a follow-up ultrasound scan was 4.4% (95% CI, 1.4-8.8%) (32/523; 15 studies), while the rates of those detected exclusively on prenatal MRI or on postnatal imaging were 5.8% (95% CI, 1.9-11.5%) (19/357; 11 studies) and 3.2% (95% CI, 0.3-9.0%) (50/660; 17 studies), respectively. The rate of an associated extra-CNS anomaly detected on a follow-up ultrasound scan was 2.9% (95% CI, 0.8-6.3%) (19/523; 15 studies), while the rates of those detected exclusively on MRI or on postnatal imaging were 0% (95% CI, 0.0-1.7%) (0/357; 11 studies) and 0.9% (95% CI, 0.3-1.8%) (4/660; 17 studies), respectively. Intrauterine death and perinatal death each occurred in 0.7% (95% CI, 0.3-1.4%) (2/824; 23 studies) of cases. In cases without an associated anomaly detected pre- or postnatally, symptomatic infection was found in 1.5% (95% CI, 0.7-2.7%) (6/548; 19 studies) of infants, the overall rate of a neurodevelopmental anomaly was 3.1% (95% CI, 1.6-5.1%) (16/550; 19 studies), and hearing problems affected 6.5% (95% CI, 3.8-10.0%) (36/550; 19 studies) of children. Subanalyses according to the trimester in which maternal infection occurred were affected by the very small number of included cases and lack of comparison of the observed outcomes in the original studies. Compared with fetuses infected in the second or third trimester, those infected in the first trimester had a relatively higher risk of having an additional anomaly detected on follow-up ultrasound or MRI, abnormal neurodevelopmental outcome and hearing problems.

CONCLUSIONS

In fetuses with congenital CMV infection in which no anomalies are detected on prenatal ultrasound or MRI, the risk of adverse postnatal outcome is lower than that reported previously in the published literature when not considering the role of antenatal imaging assessment. The results from this review also highlight the potential role of MRI, even in fetuses with no anomalies detected on ultrasound, as an anomaly can be detected exclusively on MRI in about 6% of cases. The findings from this study could enhance prenatal counseling of pregnancies with congenital CMV infection with normal prenatal imaging. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

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.

Diagnostic accuracy of prenatal ultrasound in identifying the level of the lesion in fetuses with open spina bifida: A systematic review and meta-analysis

INTRODUCTION

The role of prenatal ultrasound in correctly identifying the level of the lesion in fetuses with open spina bifida has yet to be determined. The primary aim of this systematic review was to report the diagnostic accuracy of ultrasound in determining the level of the lesion in fetuses with open spina bifida. The secondary aim was to elucidate whether prenatal magnetic resonance imaging (MRI) improves the diagnostic performance of prenatal imaging in correctly identifying the level of the lesion.

MATERIAL AND METHODS

Inclusion criteria were studies reporting the agreement between ultrasound, MRI and postnatal or postmortem assessment of fetuses with spina bifida. Agreement was defined as: complete (when the upper level of the lesion detected prenatally was the same recorded at postnatal or postmortem evaluation), within one (when the upper level of the lesion recorded prenatally was within one vertebral body higher or lower than that reported postnatally) and within two vertebral bodies (when the upper level of the lesion recorded prenatally was within two vertebral bodies higher or lower than that reported postnatally or postmortem evaluation). Meta-analyses of proportions were used to combine data.

RESULTS

Fourteen studies (655 fetuses) were included. Ultrasound was able to identify the correct level of the lesion in 40.9% (95% confidence interval [CI] 26.9-55.6) of cases. The upper level of the lesion recorded on ultrasound was within one vertebral body in 76.2% (95% CI 65.0-85.9) of cases and within two segments in 92.4% (95% CI 84.3-97.7). Fetal MRI detected the exact level of the lesion in 42.5% (95% CI 35.9-45.2) of cases; the level of the lesion recorded on MRI was higher in 26.4% (95% CI 20.0-33.3) of cases and lower in 32.4% (95% CI 25.5-39.7) than that confirmed postnatally. The upper level of the lesion recorded on MRI was within one vertebral body in 76.2% (95% CI 65.9-85.2) of cases and within two segments in 94.2% (95% CI 90.2-97.2).

CONCLUSIONS

Both ultrasound and MRI have a moderate diagnostic accuracy in identify the upper level of the lesion in fetuses with open spina bifida.

Risk factors associated with adverse fetal outcomes in pregnancies affected by Coronavirus disease 2019 (COVID-19): a secondary analysis of the WAPM study on COVID-19

Objectives To evaluate the strength of association between maternal and pregnancy characteristics and the risk of adverse perinatal outcomes in pregnancies with laboratory confirmed COVID-19. Methods Secondary analysis of a multinational, cohort study on all consecutive pregnant women with laboratory-confirmed COVID-19 from February 1, 2020 to April 30, 2020 from 73 centers from 22 different countries. A confirmed case of COVID-19 was defined as a positive result on real-time reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assay of nasal and pharyngeal swab specimens. The primary outcome was a composite adverse fetal outcome, defined as the presence of either abortion (pregnancy loss before 22 weeks of gestations), stillbirth (intrauterine fetal death after 22 weeks of gestation), neonatal death (death of a live-born infant within the first 28 days of life), and perinatal death (either stillbirth or neonatal death). Logistic regression analysis was performed to evaluate parameters independently associated with the primary outcome. Logistic regression was reported as odds ratio (OR) with 95% confidence interval (CI). Results Mean gestational age at diagnosis was 30.6±9.5 weeks, with 8.0% of women being diagnosed in the first, 22.2% in the second and 69.8% in the third trimester of pregnancy. There were six miscarriage (2.3%), six intrauterine device (IUD) (2.3) and 5 (2.0%) neonatal deaths, with an overall rate of perinatal death of 4.2% (11/265), thus resulting into 17 cases experiencing and 226 not experiencing composite adverse fetal outcome. Neither stillbirths nor neonatal deaths had congenital anomalies found at antenatal or postnatal evaluation. Furthermore, none of the cases experiencing IUD had signs of impending demise at arterial or venous Doppler. Neonatal deaths were all considered as prematurity-related adverse events. Of the 250 live-born neonates, one (0.4%) was found positive at RT-PCR pharyngeal swabs performed after delivery. The mother was tested positive during the third trimester of pregnancy. The newborn was asymptomatic and had negative RT-PCR test after 14 days of life. At logistic regression analysis, gestational age at diagnosis (OR: 0.85, 95% CI 0.8-0.9 per week increase; p<0.001), birthweight (OR: 1.17, 95% CI 1.09-1.12.7 per 100 g decrease; p=0.012) and maternal ventilatory support, including either need for oxygen or CPAP (OR: 4.12, 95% CI 2.3-7.9; p=0.001) were independently associated with composite adverse fetal outcome. Conclusions Early gestational age at infection, maternal ventilatory supports and low birthweight are the main determinants of adverse perinatal outcomes in fetuses with maternal COVID-19 infection. Conversely, the risk of vertical transmission seems negligible.

The prevalence of brain lesions after in utero surgery for twin-to-twin transfusion syndrome on third-trimester MRI: a retrospective cohort study

OBJECTIVE

Due to the increased risk of antenatal brain lesions, we offer a third-trimester magnetic resonance imaging (MRI) scan to all patients who underwent an in utero intervention for twin-twin transfusion syndrome (TTTS). However, the usefulness of such a policy has not been demonstrated yet. Therefore, we determined the prevalence of antenatal brain lesions detected on third-trimester MRI and the proportion of lesions detected exclusively on MRI.

MATERIALS AND METHODS

We conducted a retrospective cohort study of monochorionic diamniotic twin pregnancies complicated by TTTS that underwent laser coagulation of the vascular anastomoses or fetal reduction by umbilical cord occlusion between 2010 and 2017. We reviewed the third-trimester MRI findings and compared those with the prenatal ultrasonography.

RESULTS

Of the 141 patients treated with laser coagulation and 17 managed by cord occlusion, 112/141 (79%) and 15/17 (88%) patients reached 28 weeks. Of those, 69/112 (62%) and 11/15 (73%) underwent an MRI between 28 and 32 weeks. After laser coagulation, MRI detected an antenatal brain lesion in 6 of 69 pregnancies (9%) or in 6 of 125 fetuses (5%). In 4 cases (67%), the lesion was detected only on MRI. In the 11 patients treated with cord occlusion, no brain lesions were diagnosed.

CONCLUSION

The prevalence of brain lesions detected by third-trimester MRI is higher compared to prenatal ultrasonography alone, making MRI a useful adjunct to detect antenatal brain lesions in twin pregnancies after in utero treatment for TTTS.

KEY POINTS

• In utero interventions for twin-to-twin transfusion syndrome (TTTS) do not prevent the occurrence of antenatal brain lesions. • Fetal magnetic resonance imaging (MRI) has high accuracy in detecting anomalies of cortical development and can be a useful adjunct to ultrasonography in diagnosing certain brain abnormalities. • After laser coagulation of the anastomoses for TTTS, third-trimester MRI diagnosed a brain lesion that was not detected earlier on ultrasound scan in 6% of pregnancies.

Obstetrical and perinatal outcomes in fetuses with early versus late sonographic diagnosis of short femur length: A single-center, prospective, cohort study

OBJECTIVES

The aim of this study was to evaluate obstetrical and perinatal outcomes in fetuses with short femur length diagnosed before or after 24 weeks of gestation.

STUDY DESIGN

This was a prospective cohort study on singleton pregnancies with a diagnosis of fetal femur < 5 centile. Included patients were divided into two groups: patients with a first diagnosis of femur length < 5th percentile at 14-24 weeks (group A) and those with the first diagnosis made at > 24 weeks (group B).

RESULTS

147 patients were included for the analysis. Group A and group B included 66 (44.9%) and 81 (55.1%) cases. Abnormal fetal karyotype and skeletal dysplasia rates were significantly higher (27.3% vs 3.7%,P < 0.001 and 19.7% vs 3.7%, P = 0.002) in group A. Women in group B had a higher incidence of small for gestational age and intrauterine growth restriction (7.6% vs 24.7%, P = 0.007 and 19.7% vs 44.4%, P = 0.002). There was a significant higher incidence of live births in group B (34.9% vs 97.5%, P < 0.001), while the rate of termination of pregnancy was increased in group A (56.1% vs 1.2%, P < 0.001). No significant difference was found in perinatal outcomes of live births, when comparing group A and B.

CONCLUSIONS

The incidence of abnormal karyotype and skeletal dysplasia is higher when short femur length diagnosed earlier in gestation, while the incidence of small for gestational age, intrauterine growth restriction and the rate of live births are significantly increased when short femur length is diagnosed later during pregnancy.