Allogenic umbilical cord-derived mesenchymal stromal cells improve motor function in prenatal surgical repair of myelomeningocele: An ovine model study.

OBJECTIVE: To investigate the effects of an adjuvant allogenic umbilical cord mesenchymal stromal cell (UC-MSC) patch applied during fetal surgery on motor and sphincter function in the ovine MMC model. DESIGN: MMC defects were surgically created at 75 days of gestation and repaired 14 days later. POPULATION: Ovine MMC model: fetal lambs. METHODS: We compared lambs that received a UC-MSC patch with a control group of lambs that received an acellular patch. MAIN OUTCOME MEASURES: Clinical neurological assessment was performed at 2 and 24 hours of life and included determination of the Sheep Locomotor Rating scale (SLR), which has been validated in the ovine MMC model. Electrophysical examinations, spine scans and histological analyses were also performed. RESULTS: Of the 13 operated lambs, nine were born alive: five had of these had received a UC-MSC patch and four an acellular patch. At 24 hours of life, lambs in the UC-MSC group had a significantly higher score (14 versus 5, P = 0.04). Amyotrophy was significantly more common in the control group (75% versus 0%, P = 0.02). All the lambs in the control group and none of those in the UC-MSC group were incontinent. No significant differences were observed between the UC-MSC and control groups in terms of the presence of spontaneous EMG activity, nerve conduction or spinal evoked potentials. In the microscopic examination, lambs in the UC-MSC group had less fibrosis between the spinal cord and the dermis (mean thickness, 453 versus 3921 µm, P = 0.03) and around the spinal cord (mean thickness, 47 versus 158 µm, P < 0.001). Examination of the spinal cord in the area of the MMC defect showed a higher large neuron density in the UC-MSC group (14.5 versus 5.6 neurons/mm2, P < 0.001). No tumours were observed. CONCLUSIONS: Fetal repair of MMC using UC-MSC patches improves motor and sphincter function as well as spinal preservation and reduction of fibrosis.

Abnormalities of the corpus callosum. Can prenatal imaging predict the genetic status? Correlations between imaging phenotype and genotype.

OBJECTIVE: Recent studies have evaluated prenatal exome sequencing (pES) for abnormalities of the corpus callosum (CC). The objective of this study was to compare imaging phenotype and genotype findings. METHOD: This multicenter retrospective study included fetuses with abnormalities of the CC between 2018 and 2020 by ultrasound and/or MRI and for which pES was performed. Abnormalities of the CC were classified as complete (cACC) or partial (pACC) agenesis of the CC, short CC (sCC), callosal dysgenesis (CD), interhemispheric cyst (IHC), or pericallosal lipoma (PL), isolated or not. Only pathogenic (class 5) or likely pathogenic (class 4) (P/LP) variants were considered. RESULTS: 113 fetuses were included. pES identified P/LP variants for 3/29 isolated cACC, 3/19 isolated pACC, 0/10 isolated sCC, 5/10 isolated CD, 5/13 non-isolated cACC, 3/6 non-isolated pACC, 8/11 non-isolated CD and 0/12 isolated IHC and PL. Associated cerebellar abnormalities were significantly associated with P/LP variants (OR = 7.312, p = 0.027). No correlation was found between phenotype and genotype, except for fetuses with a tubulinopathy and an MTOR pathogenic variant. CONCLUSIONS: P/LP variants were more frequent in CD and in non-isolated abnormalities of the CC. No such variants were detected for fetuses with isolated sCC, IHC and PL.

Predictive factors for survival in patients with oligohydramnios secondary to antenatal kidney disease.

BACKGROUND: Renal oligohydramnios (ROH) is caused by bilateral congenital abnormalities, either of renal parenchymal or obstructive origin. ROH is a poor prognostic factor of neonatal survival; lung hypoplasia is reported to be the main cause of mortality. We aimed to describe the fetal morbidity and pre- and postnatal mortality in case of ROH due to renal congenital pathologies and to find predictive risk factors for morbidity and mortality. METHODS: All data were collected in Trousseau Hospital in the obstetric, neonatology, and pediatric nephrology units, from 2008 to 2020. RESULTS: We included 66 fetuses with renal parenchymal pathologies posterior urethral valves (PUV) (N = 25), bilateral kidney agenesis (N = 10), hypodysplasia (N = 16), and polycystic kidney disease (N = 10) causing oligohydramnios identified on antenatal ultrasound. Total pre- and postnatal mortality was 76% (50/66). Mortality, excepting termination of pregnancy (TOP), was 65%. The presence of pneumomediastinum and pneumothorax was not different in survivors and non-survivors. Fetuses with kidneys having features of hypodysplasia on ultrasound at T2 and those with oligohydramnios before 32 weeks GA had a higher risk of death. There was a significant difference in plasma creatinine of the surviving patients compared to the deceased patients, from day 3 onwards (183 µmol/L [88; 255] vs. 295 µmol/L [247; 326]; p = 0.038). CONCLUSIONS: The main differences between survivors and non-survivors among patients with "renal oligohydramnios" were oligohydramnios detection before 32 weeks GA, dysplasia detection on the second trimester ultrasound, and increase of serum creatinine from day 3 onwards. A higher resolution version of the Graphical abstract is available as Supplementary information.

Prenatal diagnosis of vermian cyst: a new type of posterior fossa cyst.

BACKGROUND: Prenatal diagnoses of cystic malformations of the posterior fossa mainly encompass arachnoid cysts, Blake's pouch cysts and Dandy-Walker syndrome. To date, vermian cysts have not been reported prenatally. OBJECTIVES: To report a series of fetuses with a vermian cyst. MATERIALS AND METHODS: This was a single-center retrospective study conducted from 2012 to 2021. We included all fetuses presenting with a vermian cyst and excluded all other types of posterior fossa cyst. The cyst was visible at prenatal ultrasound (US) and/or magnetic resonance imaging (MRI). Postnatal imaging and/or clinical outcome data were available. RESULTS: Sixteen fetuses fulfilled the inclusion criteria with a strong female predominance (n=13). US and MRI were performed at a mean gestational age of 29+5 and 33+1 weeks, respectively. In all patients, the cyst was in the vermian horizontal fissure. The mean longest dimension was about 10 mm. The vermis and other posterior fossa structures were otherwise normal. At postnatal imaging, 13 children underwent brain imaging including 11 MRIs with complete regression (n=9), stability (n=1) and increase in size (n=3) of the cyst. Psychomotor development was normal in 14 children. One child (with an inner ear malformation) showed a slight delay in walking and language acquisition. Slight walking ataxia was present in another child. CONCLUSION: We report 16 fetuses with posterior fossa cysts located within the vermis at the level of the horizontal fissure, diagnosed at US and/or MRI and carrying an overall excellent neurological prognosis.

Biodistribution of allogenic umbilical cord-derived mesenchymal stromal cells after fetal repair of myelomeningocele in an ovine model.

BACKGROUND: Myelomeningocele (MMC) is a spinal cord congenital defect that leads to paraplegia, sphincter disorders and potential neurocognitive disabilities. Prenatal surgery of MMC provides a significant benefit compared to surgery at birth. Mesenchymal stromal cell (MSC) therapy as an adjuvant treatment for prenatal surgery showed promising results in animal experiments which could be considered for clinical use in human fetuses. Despite numerous reassuring studies on the safety of MSCs administration in humans, no study focused on MSCs biodistribution after a local MSCs graft on the fetal spinal cord. AIM: The purpose of our study was to assess the biodistribution of umbilical cord-derived mesenchymal stromal cells (UC-MSCs) at birth in lambs who had a prenatal myelomeningocele repair using a fibrin patch seeded with allogenic UC-MSCs. METHODS: After isolation, UC-MSCs were tagged using a green fluorescent protein (GFP)-containing lentiviral vector. MMC defects were surgically created at 75 days of gestation and repaired 15 days later using UC-MSCs patch. Lambs were delivered at 142 days and sacrificed. DNA extraction was performed among biopsies of the different organs and q-PCR analysis was used to detect the expression of GFP (GFP DNA coding sequence). RESULTS: In our 6 surviving lambs grafted with UC-MSCs, GFP lentivirus genomic DNA was not detected in the organs. CONCLUSION: These reassuring data will support translational application in humans, especially since the first human clinical trial using mesenchymal stromal cells for in-utero treatment of MMC started recently in U.S.A.

In utero treatment of myelomeningocele with allogenic umbilical cord-derived mesenchymal stromal cells in an ovine model.

PURPOSE OF THE STUDY: The purpose of our study was to investigate the effects of ovine umbilical cord-derived mesenchymal stromal cells (UC-MSCs) seeded in a fibrin patch as an adjuvant therapy for fetal myelomeningocele repair in the ovine model. MATERIALS AND METHODS: MMC defects were surgically created at 75 days of gestation and repaired 15 days later with UC-MSCs patch or an acellular patch. At birth, motor function, tail movements, and voiding abilities were recorded. Histological and immunohistochemical analysis included study of MMC defect's healing, spinal cord, UC-MSCs survival, and screening for tumors. RESULTS: Six lambs were born alive in each group. There was no difference between the two groups on the median sheep locomotor rating score but all lambs in the control group had a score between lower than 3 compared to 50% in UC-MSCs group. There were more lambs with tail movements and voiding ability in UC-MSCs group (83% vs 0% and 50% vs 0%, respectively). gray matter area and large neurons density were higher in UC-MSCs group (2.5 vs 0.8 mm2 and 19.3 vs 1.6 neurons/mm2 of gray matter, respectively). Fibrosis thickness at the myelomeningocele scar level was reduced in UC-MSCs group (1269 µm vs 2624 µm). No tumors were observed. CONCLUSION: Fetal repair of myelomeningocele using allogenic UC-MSCs patch provides a moderate improvement in neurological functions, gray matter and neuronal preservation and prevented from fibrosis development at the myelomeningocele scar level.

Contribution of computed tomography and magnetic resonance imaging in the analysis of fetal craniofacial malformations.

A wide range of craniofacial malformations can be diagnosed in utero using ultrasonography. However, even with highly experienced sonographers and diagnostic physicians and optimal conditions of examination, some anatomical structures cannot be properly analyzed by this technique. The aim of this pictorial essay is to show the additional value of fetal magnetic resonance imaging and computed tomography in this setting and to illustrate the role of these modalities in facial clefts; craniosynostosis; ear, eye and nose abnormalities; otomandibular dysplasias; and facial cephaloceles.

Open fetal surgery for myelomeningocele repair in France.

INTRODUCTION: Open fetal myelomeningocele (MMC) surgery is currently the standard of care option for prenatal MMC repair. We described the population referred to our center and reviewed outcome after open fetal MMC repair. MATERIAL AND METHODS: All patients referred to our center for MMC were reviewed from July 2014 to June 2020. For all the patients who underwent fetal MMC repair, surgical details, maternal characteristics and data from the neonatal to the three-years-old evaluations were collected. RESULTS: Among the 126 patients referred to our center, 49.2% were eligible and 27.4% (n = 17) of them underwent fetal MMC repair. Average gestational age at fetal surgery was 24+6 weeks. There was no case of fetal complication and the only maternal complication was one case of transfusion. We recorded 70% of premature rupture of membranes and 47% of premature labor. Average gestational age at delivery was 34+2 weeks and no patient delivered before 30 weeks. There was no case of uterine scar dehiscence or maternal complication during cesarean section. After birth, 59% of the children had a hindbrain herniation reversal. At 1-year-old, 42% were assigned a functional level of one or more better than expected according to the prenatal anatomic level and 25% required a ventriculoperitoneal shunt. At 3-year-old, all the children attended school and 75% were able to walk with orthotics or independently. CONCLUSION: Open fetal surgery enables anatomical repair of the MMC lesion, a potential benefit on cerebral anomalies and motor function, with a low rate of perinatal and maternal complications.

Intrahepatic cholestasis of pregnancy associated with azathioprine: A case series.

BACKGROUND: Intrahepatic cholestasis of pregnancy (ICP) is characterised by otherwise unexplained maternal pruritus, increased serum bile acid concentration over 10 µmol/L and spontaneous relief of symptoms and liver abnormalities after delivery. It occurs most frequently during the third trimester and is usually not induced by medication. Besides, azathioprine is recommended as first-line immunosuppressant in patients with steroid-dependent inflammatory bowel disease and is allowed during pregnancy, in order to stabilize maternal disease. METHODS: We reviewed all cases of ICP between 2010 and 2018 in two French perinatal centers. RESULTS: We encountered eight pregnancies complicated by atypical ICP among patients treated with azathioprine. ICP associated with azathioprine appears to be biologically more severe and to occur earlier than "standard" ICP. Furthermore, clinical and biochemical abnormalities related to ICP disappear when azathioprine is discontinued. Azathioprine safety should be reconsidered and practitioners advised to discuss discontinuing this drug as soon as ICP diagnosis is established.

Prevention of Neural Tube Defects by Folic Acid Supplementation: A National Population-Based Study.

Folic acid supplementation is recommended for neural tube defect prevention during pregnancy. We conducted an observational, retrospective national registry study to determine the rate of dispensing of periconceptional folic acid after prescription in a sample of French women representative of the general population. Our study population (n = 186,061) was a representative sample of the French population, recorded in the Health Data System database on pharmacy dispensing of medication and mandatory reporting of pregnancy. Between 2006 and 2016, 14.3% of pregnant women had a prescription for folic acid supplementation during the month preceding conception and for the first 12 weeks of pregnancy. Of these prescriptions, 30.9% were issued before the start of pregnancy. This percentage was lower for first pregnancies. The rate of pharmacy dispensing during the preconception period increased progressively from 3.8% to 8.3% between 2006 and 2016. In France, the rate of pharmacy dispensing of periconceptional folic acid after medical prescription is very low and does not follow international recommendations. It seems essential to implement awareness-raising policies targeting the general population and physicians regarding effective periconceptional supplementation, particularly starting in the preconception period. Clarification of international recommendations and fortification of flour could improve the efficacy of folate supplementation at population level.

Prenatal ultrasonography of autosomal dominant polycystic kidney disease mimicking recessive type: case series.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited renal disease. This pathology has been increasingly diagnosed in utero and several sonographic patterns are well described in the literature. OBJECTIVE: To present a series of fetuses with an unusual imaging pattern of ADPKD, mimicking autosomal recessive polycystic kidney disease (ARPKD). MATERIALS AND METHODS: We retrospectively reviewed second-line ultrasound (US) scans performed for suspicion of fetal kidney pathology between 2006 and 2018. Inclusion criteria were (1) proven ADPKD on the basis of a known family history and/or of genetic testing and (2) US features suggestive of ARPKD. We recorded the clinical, imaging, genetic and pathological findings in cases with pregnancy termination. RESULTS: Three out of 12 patients with proven ADPKD diagnosed in utero presented with US features suggestive of ARPKD. Furthermore, an additional patient observed at another institution was added to the series. History of familial ADPKD was present in three cases. US showed enlarged kidneys with increased cortical echogenicity, decreased corticomedullary differentiation, multiple medullary cysts and decreased amniotic fluid in all four cases. Pregnancy was terminated in two cases (histology confirmed features in keeping with ADPKD), one premature neonate died (histology in progress) and one child is alive. Genetic testing showed a homozygous mutation of the PKD1 gene in two patients, a heterozygous mutation of the PKD1 gene in one patient and was not performed in the remaining patient. CONCLUSION: This series describes an unusual sonographic prenatal presentation of ADPKD, not yet well described in the radiologic literature, mimicking ARPKD.

Two-Port Fetoscopic Repair of Myelomeningocele in Fetal Lambs.

OBJECTIVE: The aim of this study was to assess the feasibility and the effectiveness of a fetoscopic myelomeningocele (MMC) repair with a running single suture using a 2-port access in the sheep model. METHODS: Eighteen fetuses underwent surgical creation of a MMC defect at day 75. Fetuses were then randomized into 3 groups. Four fetuses remained untreated (control group). In the other 14 fetuses, a prenatal repair was performed at day 90: 7 fetuses had an open repair (oMMC), and 7 fetuses had a fetoscopic repair (fMMC) using a single-layer running suture through a 2-port access. Lambs were sacrificed at term, and histological examinations were performed. RESULTS: Hindbrain herniation was observed in all live lambs in the control group. A complete closure of the defect was achieved in all the lambs of the fMMC group. A complete healing of the defect and no hindbrain herniation were observed in all live lambs of the oMMC and fMMC groups. The durations of surgeries were not statistically different between the oMMC and the fMMC groups (60 vs. 53 min, p = 0.40), as was the risk of fetal loss (fMMC: 1/7, oMMC: 3/7, p = 0.56). DISCUSSION: Fetoscopic repair of MMC can be performed using a single-layer running suture through a 2-port access and may be promising to reduce the risk of premature rupture of membranes.

Variable prenatal presentation of Pfeiffer syndrome: Suggested aids to prenatal sonographic diagnosis.

BACKGROUND: Our purpose was to describe and compare the cranial and extracranial abnormalities of Pfeiffer syndrome on prenatal imaging with postnatal or postmortem findings, which may help in prenatal diagnosis of Pfeiffer syndrome (PS). METHODS: Cases of fetuses with a confirmed diagnosis of PS over a 4-year period (2012-2016) were retrospectively reviewed. Prenatal imaging findings, postnatal, or postmortem investigations and genetic test results were analyzed. RESULTS: Four fetuses were ascertained, 3 with prenatal sonographic findings compatible with PS and one only diagnosed at postmortem. Cases were referred between 22 and 24 weeks' gestation. Three of the 4 cases were terminated, and details of postmortem/postnatal examination were available in all. There was variable presentation of features. Craniosynostosis was present in 3 cases, but only detected prenatally in 2. Extracranial signs included abnormalities of thumbs and/or big toes, detected prenatally in 3 of the 4 cases. A sacral appendage and vertebral or coronal clefts were present at postmortem in 3 cases but only detected prenatally in one. A cartilaginous tracheal sleeve was detected at postmortem in all 3 cases but not detected by prenatal ultrasound. Other findings included ventriculomegaly, posterior fossa, and facial anomalies. Molecular testing revealed mutations of the fibroblast growth factor receptor 2 (FGFR2) gene in all cases. CONCLUSION: Pfeiffer syndrome has a highly variable phenotype, and the absence of craniosynostosis on prenatal US does not exclude the diagnosis. Presence of abnormal thumbs and big toes, a sacral appendage, vertebral fusions, and coronal clefts should lead to prenatal molecular testing for PS.

Fetoscopic patch coverage of experimental myelomenigocele using a two-port access in fetal sheep.

PURPOSE: This study aims to assess the feasibility and the effectiveness of a fetoscopic myelomeningocele (MMC) coverage using a sealed inert patch through a two-port access, in the sheep model. METHODS: Forty-four fetuses underwent surgical creation of a MMC defect at day 75 and were divided into four groups according to the MMC repair technique, performed at day 90. Group 1 remained untreated. Group 2 had an open surgery using suture of the defect. Groups 3 and 4 underwent defect coverage using a Gore®-polytetrafluoroethylene patch secured with surgical adhesive (Bioglue®), with an open approach (group 3) and a fetoscopic one (group 4). Lambs were killed at term, and histological examinations were performed. RESULTS: Fetoscopic patch coverage was achieved in all the lambs of group 4. All the fetuses of group 2 had a complete closure of the defect whereas only 38% in group 3 and 14% in group 4. Fetal loss rate seems to be lower in group 4 than in groups 2 and 3. CONCLUSION: Fetoscopic coverage of MMC defect can be performed using a sealed patch through a two-port access, but the patch and glue correction may not be the ideal technique to repair fetal MMC.