Fetal Magnetic Resonance Imaging Research Articles

Fetal intracranial hemorrhage: role of fetal MRI.

To date, prenatal diagnosis of intracranial hemorrhage (ICH) is mainly based on ultrasound (US) findings rather than magnetic resonance imaging (MRI). We aimed to investigate the role of MRI in the diagnosis of fetal ICH among pregnancies referred to fetal MRI and to characterize the topography of fetal ICH using MRI. We retrospectively identified fetal ICH cases diagnosed by MRI from 2008 to 2015 and reviewed their prenatal and postnatal medical records. Of the 2638 MRIs performed during the study period, 36 had ICH (median age 27weeks). The most common US indication for MRI was a suspected cerebral anomaly (86%): 20 (55%) fetuses were referred for ventriculomegaly, 8 (22%) for ICH, and the other 8 had a variety of different indications. We distinguished two broad topographic patterns: (1) those related to hemorrhage of the periventricular germinal matrix (GMH, n=24; 67%) and (2) those not related to GMH (non-GMH, n=12; 33%). GMH fetuses were referred to MRI later (median 28 vs 22weeks, p=0.005). Intrauterine demise was more frequent in non-GMH (58% vs 4%, p<0.001). Magnetic resonance imaging is an important tool in prenatal diagnosis of ICH, especially when US describes nonspecific intracranial abnormalities. GMH occurs more frequently and later in pregnancy than non-GMH. © 2017 John Wiley & Sons, Ltd.

Should isolated fetal ventriculomegaly measured below 12 mm be viewed as a variant of the norm? Results of a 5-year experience in a prenatal referral center

Background: Fetal ventriculomegaly (VM) is defined as lateral ventricles measured above 10 mm. Some authors believe VM <12 mm are variants of the norm and need not be addressed for referral ultrasound.Methods: A retrospective continuous cohort study of 127 confirmed fetal VM was divided into three groups after initial referral sonographic assessment: isolated VM <12 mm (group A), isolated VM ≥12 mm (group B), and VM associated with other malformations (group C). We reviewed obstetric outcome and neonate evolution after 1 month with the aim of defining a pertinent prenatal workup.Results: We reported fetal infections in all groups (p = .24) and chromosomal abnormalities only in group C (p = .41). Fetal magnetic resonance imaging (MRI) found initially undiagnosed brain abnormalities in groups B and C (12.5 and 14.1%, p < .05). Ratios of healthy children after 1 month stemming, respectively, from groups A, B, and C were 66.7, 62.5, and 20.2% (p < .05).Conclusions: Our results are in favor of a systematic referral ultrasound for every fetal VM, regardless of size, as soon as definition criterion is met. Additional paraclinical assessment (maternal serologic status for toxoplasmosis and cytomegalovirus, amniocentesis, fetal cerebral MRI) should be discussed depending on the situation.

Different information by MRI compare to ultrasound in fetal intracranial space occupying lesions.

The purpose of this study was to evaluate the value of prenatal magnetic resonance imaging (MRI) in characterizing fetal intracranial space occupying lesions in comparison to prenatal ultrasound. This retrospective study included 50 fetuses (mean age 26years, mean gestational weeks 31+1 GW) with intracranial space occupying lesions, suspected by prenatal screening ultrasound. T2-weighted, T1-weighted, SSFP, and diffusion-weighted sequences of the fetal brain were obtained on a 1.5T unit. Pathology (n=5), postmortem MRI (n=3), or postnatal US (n=42) was available as standard of reference. The fetal MRI provided correct diagnosis in 49 cases (98%), while 35 (70%) by ultrasound, and MRI failed in 1 case (2%), while ultrasound failed in 15 cases (30%). Fetal MR and ultrasound were concordant in 35 of 50 cases (70%), completely discordant in 4 (8%), and partially discordant in 11 (22%) cases. MRI could provide detailed information about the minor lesions, such as focal hemorrhage and periventricular nodules. Meanwhile, it could provide whole view of the lesion in order to delineate the surrounding anatomical structure. But there are still some limitations of its soft-tissue resolution in a case with teratoma; more effort is needed to improve the sequences.

Serial Head and Brain Imaging of 17 Fetuses With Confirmed Zika Virus Infection in Colombia, South America.

To evaluate fetal ultrasound and magnetic resonance imaging findings among a series of pregnant women with confirmed Zika virus infection to evaluate the signs of congenital Zika syndrome with respect to timing of infection. We conducted a retrospective case series of pregnant women referred to two perinatal clinics in Barranquilla and Ibagué, Colombia, who had findings consistent with congenital Zika syndrome and Zika virus infection confirmed in maternal, fetal, or neonatal samples. Serial ultrasound measurements, fetal magnetic resonance imaging results, laboratory results, and perinatal outcomes were evaluated. We describe 17 cases of confirmed prenatal maternal Zika virus infection with adverse fetal outcomes. Among the 14 symptomatic women, the median gestational age for maternal Zika virus symptoms was 10 weeks (range 7-14 weeks of gestation). The median time between Zika virus symptom onset and microcephaly (head circumference less than 3 standard deviations below the mean) was 18 weeks (range 15-24 weeks). The earliest fetal head circumference measurement consistent with microcephaly diagnosis was at 24 weeks of gestation. The earliest sign of congenital Zika syndrome was talipes equinovarus, which in two patients was noted first at 19 weeks of gestation. Common findings on fetal magnetic resonance imaging were microcephaly, ventriculomegaly, polymicrogyria, and calcifications. Our analysis suggests a period of at least 15 weeks between maternal Zika virus infection in pregnancy and development of microcephaly and highlights the importance of serial and detailed neuroimaging.

Auto-Context Convolutional Neural Network (Auto-Net) for Brain Extraction in Magnetic Resonance Imaging.

Brain extraction or whole brain segmentation is an important first step in many of the neuroimage analysis pipelines. The accuracy and the robustness of brain extraction, therefore, are crucial for the accuracy of the entire brain analysis process. The state-of-the-art brain extraction techniques rely heavily on the accuracy of alignment or registration between brain atlases and query brain anatomy, and/or make assumptions about the image geometry, and therefore have limited success when these assumptions do not hold or image registration fails. With the aim of designing an accurate, learning-based, geometry-independent, and registration-free brain extraction tool, in this paper, we present a technique based on an auto-context convolutional neural network (CNN), in which intrinsic local and global image features are learned through 2-D patches of different window sizes. We consider two different architectures: 1) a voxelwise approach based on three parallel 2-D convolutional pathways for three different directions (axial, coronal, and sagittal) that implicitly learn 3-D image information without the need for computationally expensive 3-D convolutions and 2) a fully convolutional network based on the U-net architecture. Posterior probability maps generated by the networks are used iteratively as context information along with the original image patches to learn the local shape and connectedness of the brain to extract it from non-brain tissue. The brain extraction results we have obtained from our CNNs are superior to the recently reported results in the literature on two publicly available benchmark data sets, namely, LPBA40 and OASIS, in which we obtained the Dice overlap coefficients of 97.73% and 97.62%, respectively. Significant improvement was achieved via our auto-context algorithm. Furthermore, we evaluated the performance of our algorithm in the challenging problem of extracting arbitrarily oriented fetal brains in reconstructed fetal brain magnetic resonance imaging (MRI) data sets. In this application, our voxelwise auto-context CNN performed much better than the other methods (Dice coefficient: 95.97%), where the other methods performed poorly due to the non-standard orientation and geometry of the fetal brain in MRI. Through training, our method can provide accurate brain extraction in challenging applications. This, in turn, may reduce the problems associated with image registration in segmentation tasks.

Magnetic resonance imaging of fetal persistent left superior vena cava

This study aimed to evaluate the diagnostic accuracy of fetal magnetic resonance imaging (MRI) for persistent left superior vena cava (LSVC). Prenatal echocardiography (echo) and/or ultrasound (US) and MRI data for 49 fetuses with persistent LSVC, confirmed via postnatal diagnoses between January 2010 and October 2015, were retrospectively reviewed. All prenatal MRI was performed at 1.5 T. Imaging sequences included steady-state free-precession (SSFP), single-shot turbo spin echo (SSTSE), and other sequences. All 49 cases of fetal persistent LSVC were correctly diagnosed via MRI, but only 34 cases (69.4%) were correctly diagnosed via an initial US and/or echo before MRI. Of the 15 cases that were not correctly diagnosed via US and/or echo, 8 had congenital heart diseases (CHDs) and 7 were without CHDs; however, they were associated with extracardiac abnormalities or maternal obesity. Thirty-five cases were associated with other cardiovascular abnormalities; 8, with extracardiac abnormalities; and 6, with no associated condition. In 44 (89.8%) cases, the innominate veins were absent; the remaining cases had innominate veins. In 14.3% of patients (7 cases), the persistent LSVC drained directly into the atrium. Fetal MRI can detect persistent LSVC and play an adjunctive role along with US in the evaluation of persistent LSVC.

Neurodevelopmental outcome of isolated ventriculomegaly: a prospective cohort study.

Data regarding the neurodevelopmental outcome of children diagnosed in utero with isolated ventriculomegaly (IVM) are limited and principally founded on ultrasound-based studies. Here, we endeavored to assess the outcome of such cases in a large-scale, magnetic resonance imaging (MRI)-based study. We conducted a study on 133 cases of IVM with a documented fetal brain MRI scan. Children were assessed at ages 18 to 36months by using the Vineland Adaptive Behavior Scales (VABS). Vineland Adaptive Behavior Scales scores were within normal range. There was no significant difference between VABS score in symmetric versus asymmetric IVM (101.7 vs. 101.6, respectively; p=0.94), and the VABS score of mild IVM was comparable with that of moderate IVM (101.8 vs. 101; p=0.8). Only five cases (3.8%) were found to have an abnormal score (<85). There was no significant difference in the rate of abnormal scores between mild and moderate IVM (2.8% vs. 8.3%, respectively; p=0.22). In cases of isolated ventriculomegaly, a normal neurodevelopmental outcome is to be expected; moreover, the outcome does not appear to be affected by the severity or asymmetry of the ventriculomegaly. Thus, following a meticulous workup, patients can be given reassuring counseling regarding the child's prognosis. © 2017 John Wiley & Sons, Ltd.

Prenatal diagnosis of spina bifida: from intracranial translucency to intrauterine surgery.

Accurate and timely prenatal diagnosis of spina bifida (SB) is a major goal of modern antenatal care. Prenatal screening for open SB should be first performed at the time of routine first-trimester ultrasound by examining the posterior fossa for obliteration or non-visualization of the fourth ventricle ("intracranial translucency") and cisterna magna. The second step of screening is the second-trimester anatomy scan, at which time the features of the Chiari type II malformation should be looked for, including ventriculomegaly, scalloping of the frontal bones ("lemon" sign), and backward and caudal displacement of the cerebellar vermis with obliteration of the cisterna magna ("banana" sign). In cases with positive findings, evaluation must include a focused examination of the spine for defects. In cases of closed SB and SB occulta, the cranial and posterior fossa features will not be present as they are not associated with leaking of spinal fluid and resultant hindbrain herniation, highlighting the fact that the spine should be examined thoroughly whenever possible during the second-trimester scan. In tertiary fetal medicine centers, two-dimensional and three-dimensional ultrasound allows an accurate determination of the location, type, extent, and upper level of the spinal defect as well as the presence of associated anomalies. Fetal magnetic resonance imaging should be restricted to candidates for intrauterine surgery as part of the preoperative protocol.

Cervical teratomas

Cervical teratomas

Application of MRI in prenatal diagnosis of congenital heart disease

Congenital heart disease(CHD)is one of the main causes of newborn death, which makes the prenatal diagnosis of CHD the hot spot of perinatology.Fetal echocardiography has high sensitivity in diagnosing fetal CHD in mid-gestational age of pregnancy, and is considered world-widely as the gold standard.Rapid advance has been achieved for the past decades in the technology of fetal cardiac magnetic resonance imaging(MRI). The advantages of fetal cardiac MRI including broad vision of interest and good reproducibility could make up for the deficiency of fetal echocardiography.However, some technical problems significantly limit the clinical application of it.Nowadays, fetal cardiac MRI has been utilized as a supplementary method in prenatal diagnosis of fetal CHD.This article reviews the application, advantages and limitations of fetal cardiac MRI in fetal CHD diagnosis. Key words: Fetal congenital heart disease; Fetal cardiac MRI

Predicting postnatal renal function of prenatally detected posterior urethral valves using fetal diffusion-weighted magnetic resonance imaging with apparent diffusion coefficient determination.

The objective of this study was to evaluate the accuracy of fetal diffusion-weighted magnetic resonance imaging with apparent diffusion coefficient (ADC) determination to predict postnatal renal function (nadir creatinine at 1 year and eGFR) of men with posterior urethral valves (PUV). Between 2003 and 2014, 11 MRI were performed on fetuses (between 28 and 32weeks) in whom second trimester sonography suggested severe bilateral urinary tract anomalies, suspected of PUV. The ADC of the 11 fetuses ranged from 1.3 to 2.86mm2 s-1 (median=1.79mm2 s-1 , normal range for fetal kidney: 1.1-1.8). Two pregnancies with ADC>2.6mm2 s-1 were interrupted; the autopsy confirmed PUV and Potter syndrome. For the remaining nine babies, the follow-up was 5.4years (0.8-10). Four children with abnormal ADC (1.8-2.3) had chronic kidney disease. The remaining five cases with normal nadir creatinine and eGFR had normal ADC. One case with unilateral elevated ADC had a poor ipsilateral renal function on dimercaptosuccinic acid scan. Here, it seems that diffusion-weighted magnetic resonance imaging with ADC determination could be useful in accurately evaluating fetal kidneys in PUV and predicting renal function. It may be an additional, non-invasive method when biologic and sonographic findings are inconclusive, especially in the case of oligohydramnios. Further studies are needed to confirm our data. © 2017 John Wiley & Sons, Ltd.

Beyond the uterine environment: a nonhuman primate model to investigate maternal-fetal and neonatal outcomes following chronic intrauterine infection.

BackgroundIntrauterine infection is a significant cause of early preterm birth. We have developed a fetal-neonatal model in the rhesus macaque to determine the impact of chronic intrauterine infection with Ureaplasma parvum on early neonatal reflexes and brain development.MethodsTime-mated, pregnant rhesus macaques were randomized to be inoculated with U. parvum (serovar 1; 105cfu) or control media at ~120 dGA. Neonates were delivered by elective hysterotomy at 135–147 dGA (term=167d) stabilized and cared for in our nonhuman primate neonatal intensive care unit. Neonatal reflex behaviors were assessed from birth and fetal and postnatal brain MRIs were performed.ResultsA total of 13 preterm and 5 term macaque infants entered the study. 10 preterm infants survived to 6 months of age. U. parvum infected preterm neonates required more intensive respiratory support than control infants. MRI suggest potential perturbation of brain growth and white matter maturation with exposure to intra-amniotic infection.ConclusionWe have demonstrated the feasibility of longitudinal fetal-neonatal studies in the preterm rhesus macaque after chronic intrauterine infection. Future studies will examine long-term neurobehavioral outcomes, cognitive development, neuropathology and in vivo brain imaging to determine the safety of antenatal antibiotic treatment for intrauterine infection.

Fetal brain injury in complicated monochorionic pregnancies: diagnostic yield of prenatal MRI following surveillance ultrasound and influence on prognostic counselling.

This study aimed to determine the additional diagnostic information provided by prenatal (fetal) magnetic resonance imaging (pMRI) following tertiary ultrasound (US) for fetal cranial abnormalities in complicated monochorionic gestations. Women with complicated monochorionic gestations complicated by twin-twin transfusion syndrome, co-twin demise (CD), selective intrauterine growth restriction, and/or twin anaemia-polycythaemia sequence who were referred for pMRI after tertiary US were included. Additional diagnostic information by pMRI that changed prognostic counselling was the primary outcome. Thirty-three women with 48 live fetuses had pMRI at a median of 25weeks (range: 21-29). Three of ten survivors of spontaneous CD, one of eight survivors of CD after twin-twin transfusion syndrome and 1/30 co-survivors had diagnostic information added by pMRI that altered counselling; US was normal in two and in the other three underrepresented parenchymal injury (5/33=15%; 95% confidence interval ±0.27-0.03). Additional findings included occipital lobe infarction, hemispheric injury, dural sinus thrombosis, ischaemia-producing polymicrogyria and intraventricular haemorrhage. Another 8/33 women had additional information provided by pMRI that did not alter counselling. Prenatal magnetic resonance imaging resulted in changed prognostic counselling in 5/33 pregnancies. Evaluation of incorporation of pMRI into routine surveillance of complicated monochorionic gestations is needed. © 2017 John Wiley & Sons, Ltd.

Neuroimaging, cardiovascular physiology, and functional outcomes in infants with congenital heart disease.

This review integrates data on brain dysmaturation and acquired brain injury using fetal and neonatal magnetic resonance imaging (MRI), including the contribution of cardiovascular physiology to differences in brain development, and the relationship between brain abnormalities and subsequent neurological impairments in infants with congenital heart disease (CHD). The antenatal and neonatal period are critical for optimal brain development; the developing brain is particularly vulnerable to haemodynamic disturbances during this time. Altered cerebral perfusion and decreased cerebral oxygen delivery in the antenatal period can affect functional and structural brain development, while postnatal haemodynamic fluctuations may cause additional injury. In critical CHD, brain dysmaturation and acquired brain injury result from a combination of underlying cardiovascular pathology and surgery performed in the neonatal period. MRI findings in infants with CHD can be used to evaluate potential clinical risk factors for brain abnormalities, and aid prediction of functional outcomes at an early stage. In addition, information on timing of brain dysmaturation and acquired brain injury in CHD has the potential to be used when developing strategies to optimize neurodevelopment.

Fetal ventriculomegaly: Diagnosis, treatment, and future directions.

Fetal ventriculomegaly (VM) refers to the enlargement of the cerebral ventricles in utero. It is associated with the postnatal diagnosis of hydrocephalus. VM is clinically diagnosed on ultrasound and is defined as an atrial diameter greater than 10mm. Because of the anatomic detailed seen with advanced imaging, VM is often further characterized by fetal magnetic resonance imaging (MRI). Fetal VM is a heterogeneous condition with various etiologies and a wide range of neurodevelopmental outcomes. These outcomes are heavily dependent on the presence or absence of associated anomalies and the direct cause of the ventriculomegaly rather than on the absolute degree of VM. In this review article, we discuss diagnosis, work-up, counseling, and management strategies as they relate to fetal VM. We then describe imaging-based research efforts aimed at using prenatal data to predict postnatal outcome. Finally, we review the early experience with fetal therapy such as in utero shunting, as well as the advances in prenatal diagnosis and fetal surgery that may begin to address the limitations of previous therapeutic efforts.

Erratum.

Annals of NeurologyVolume 81, Issue 6 p. 912-912 ErratumFree Access Erratum This article corrects the following: Pseudofeeders on fetal magnetic resonance imaging predict outcome in vein of Galen malformations Guillaume Saliou MD, PhD, Irène Vraka MD, Jean-Paul Teglas MD, Marie-Victoire Senat MD, PhD, Philippe Durand MD, Claire Colmant MD, Augustin Ozanne MD, Jelena Martinovic MD, Pierre Tissiere MD, PhD, Catherine Adamsbaum MD, PhD, Volume 81Issue 2Annals of Neurology pages: 278-286 First Published online: February 23, 2017 First published: 16 May 2017 https://doi.org/10.1002/ana.24942AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat In the article noted below,1 the affiliations and degrees for Catherine Adamsbaum were set incorrectly. The correct information is “Catherine Adamsbaum, MD,3,8,9”. The typesetter regrets this error. Reference 1 Saliou G, Vraka I, Teglas J-P, et al. Pseudofeeders on fetal magnetic resonance imaging predict outcome in vein of Galen malformations. Ann Neurol 2017; 81: 278– 286. Volume81, Issue6June 2017Pages 912-912 ReferencesRelatedInformation

Prognostic significance of an antenatal magnetic resonance imaging staging system on airway outcomes of fetal craniofacial venolymphatic malformations

BackgroundThe aim of the article was to determine if anatomical findings on fetal magnetic resonance imaging (MRI) of venolymphatic malformations of the face and neck (VLMFN) can be used to create a staging system predictive of airway outcomes. MethodsWe reviewed 13 fetuses evaluated for VLMFN. Stage was assigned based on anatomical findings on fetal MRI. Stage I: no evidence of polyhydramnios with free egress of amniotic fluid and clear visualization of the aryepiglottic folds and larynx. Stage II: lesions of the tongue or epiglottis but with normal aryepiglottic folds without polyhydramnios. Stage III: lesions of the tongue or larynx; nonvisualization of the aryepiglottic folds without free egress of amniotic fluid along with polyhydramnios. ResultsSix met stage I criteria with no airway involvement, nor any subsequent issues. Two met stage II criteria and were managed by ex-utero intrapartum therapy and intubated. One had minimal involvement of the upper airway, was extubated, and had no subsequent issues. Child two had involvement of the tongue and larynx and received a tracheostomy. Five were assigned stage III, delivered by ex-utero intrapartum therapy and intubated. Postnatal evaluation showed involvement of the upper airway by the lesion and was managed with tracheostomy. All treated by tracheostomy remain cannulated because of persistent symptomatic lesions at follow-up (relative risk 4.0; confidence interval 1.2-13.3). Median follow-up was 4 y (range 2-7 y). ConclusionsAlthough numbers are small, data suggest anatomical details obtained by antenatal fetal MRI appear to correlate with airway outcomes in children affected by a VLMFN. This information may be useful when counseling expectant families of affected fetuses.

Outcome of isolated enlarged cisterna magna identified in utero: experience at a single medical center in mainland China

The objective of this study is to explore the effects of prenatal isolated enlarged cisterna magna (IECM) on postnatal development. We followed up 123 fetuses with an enlarged cisterna magna (ECM), who were divided into IECM (group 1) and non-IECM (ECM plus other anomalies, group 2) groups, and compared 60 normal infants with normal fetal ultrasound. We assessed infants postnatally using the Gesell Developmental Schedules. Fetal magnetic resonance imaging, karyotyping, and chromosomal microarray analysis test were offered. The developmental quotients of gross motor and adapting abilities were significantly lower in infants with IECM compared with normal infants (80.81±3.44 vs 99.20±4.54 and 98.70±3.27 vs 100.30±5.33, respectively), and the depths ≥15mm and 13 to 14.90mm were associated with significantly lower adapting abilities (P<0.03 and P<0.05) compared with the normal (97.16±2.17 and 98.21±1.76 vs 100.30±5.33, respectively), while these scores were still within the borderline range, and the other subtests were not significantly different. Furthermore, the group 2 showed a significantly worse performance in the test. The outcome of children with IECM may be guarded, especially some subtle deficits in adapting and gross motor abilities. In contrast, the developmental quotients of infants with prenatal non-IECM were lower than that those of normal infants. © 2017 John Wiley & Sons, Ltd.

Utility of fetal cardiac magnetic resonance imaging to assess fetuses with right aortic arch and right ductus arteriosus

Objective: To evaluate the utility of fetal cardiac magnetic resonance imaging (MRI) to diagnose right aortic arch (RAA) with right ductus arteriosus. Methods: This retrospective study included six fetuses with right aortic arch and right ductus arteriosus. The six fetal cases were examined using a 1.5-T magnetic resonance unit. The steady-state free precession (SSFP) and single-shot turbo spin echo (SSTSE) sequences were used to evaluate the fetal heart and airway. The gestational age of the six fetuses ranged from 22 to 35 weeks (mean, 26.5 weeks). The age of the pregnant women ranged from 23 to 40 years (mean 31 years). Results: Fetal cardiac MRI diagnosed the six fetal cases with RAA with right ductus arteriosus correctly. Among the six fetuses, four were associated with other congenital heart defects. In three of six cases, the diagnoses established using prenatal echocardiography (echo) was correct when compared with postnatal diagnosis. Conclusions: Fetal cardiac MRI is a useful complementary tool to assess fetuses with RAA and right ductus arteriosus.

First 60 fetal in-utero myelomeningocele repairs at Saint Louis Fetal Care Institute in the post-MOMS trial era: hydrocephalus treatment outcomes (endoscopic third ventriculostomy versus ventriculo-peritoneal shunt).

The published results of the Management of Myelomeningocele Study (MOMS) trial in 2011 showed improved outcomes (reduced need for shunting, decreased incidence of Chiari II malformation, and improved scores of mental development and motor function) in the fetal prenatal repair group compared to the postnatal group. Historically, endoscopic third ventriculostomy (ETV) remains as a controversial hydrocephalus treatment option with high failure rates in pediatric patients with a history of myelomeningocele (MMC). We report hydrocephalus treatment outcomes in the fetal in-utero myelomeningocele repair patients who underwent repair at our Saint Louis Fetal Care Institute following the MOMS trial. We looked carefully at ETV outcomes in this patient population and we identified risk factors for failure. At our Saint Louis Fetal Care Institute, we followed the maternal and fetal inclusion and exclusion criteria used by the MOMS trial. The records of our first 60 fetal MMC repairs performed at our institute between 2011 and 2017 were examined. We retrospectively reviewed the charts, prenatal fetal magnetic resonance imaging (MRI) and ultrasound (US) imaging findings, postnatal brain MRI, and Bayley neurodevelopment testing results for infants and children who underwent surgical treatment of symptomatic hydrocephalus (VP shunt versus ETV). Multiple variables possibly related to ETV failure were considered for identifying risk factors for ETV failure. Between May 2011 and March 2017, 60 pregnant female patients underwent the prenatal MMC repair for their fetuses between 20 and 26weeks' gestational age (GA) utilizing the standard hysterotomy for exposure of the fetus, and microsurgical repair of the MMC defect. All MMC defects underwent successful in-utero repair, with subsequent progression of the pregnancy. At the time of this study, 58 babies have been born, 56 are alive since there were 2 mortalities in the neonatal period due to prematurity. One patient was excluded given lack of consent for research purposes. From the remaining 55 patient included in this study, a total of 30 infants and toddlers underwent treatment of hydrocephalus (ETV and VPS groups). Twenty-five patients underwent ETV (24 primary ETV and 1 after shunt failure). Nineteen patients underwent shunt placements (6 primary/13 after ETV failure). Mean GA at time of MMC repair for the ETV group was 24+6/7weeks (range 22+4/7 to 25+6/7). Mean follow up for patients who had a successful ETV was 17.25months (range 4-57months). Bayley neurodevelopmental testing results were examined pre- and post-ETV. Overall ETV success rate was 11/24 (45.8%) at the time of this study. The total number of patients who underwent shunt placement was 19/55 (34.5%), while shunting rate was 40% in the MOMS trial. Using a simple logistic regression analysis to identify predictors of ETV failure, ETV age ≤6months and gestational age ≥23weeks at repair of myelomeningocele were significant predictors for ETV failure while in-utero ventricular stability ≤4mm and in-utero ventricular size post-repair ≤15.5mm were significant predictors for ETV success. None of the listed variables independently predicted classification into ETV success versus ETV failure groups when entered into multiple logistic regression analysis. ETV, as an alternative to initial shunting, may continue to show promising results for treating fetal MMC repair patient population who present with symptomatic hydrocephalus during infancy and early childhood. Although our overall CSF diversion rate (ETV and VPS groups) in our fetal MMC group is higher than the MOMS trial, our shunting rate is lower given our higher incidence of patients with successful ETV. To our knowledge, this is the largest reported ETV series in patients who underwent fetal MMC repair. ETV deserves a closer look in the setting of improved hindbrain herniation in fetal in-utero MMC repair patients. In our series, young age (less than 6months) and late GA at time of fetal MMC repair (after 23weeks GA) were predictors for ETV failure, while in-utero stability of ventricular size (less than 4mm) and in-utero ventricular size post-repair ≤15.5mm were predictors for ETV success. Larger series and potential prospective randomized studies are required for further evaluation of risk factors for ETV failure in the fetal MMC patient population.