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Objective: Fetoscopic closure of spina bifida using heated and humidified carbon dioxide gas (hhCO 2 ) has been associated with lower maternal morbidity compared with open closure. Fetal cardiovascular changes during these surgical interventions are poorly defined. Our objective was to compare fetal bradycardia (defined as fetal heart rate (FHR) < 110 bpm for 10 min) and changes in umbilical artery (UA) Doppler parameters during open vs fetoscopic closure., Methods: This was a prospective cohort study of 22 open and 46 fetoscopic consecutive in-utero closures conducted between 2019 and 2023. Both cohorts had similar preoperative counseling and clinical management. FHR and UA Doppler velocimetry were obtained systematically during preoperative assessment, every 5 min during the intraoperative period, and during the postoperative assessment. FHR, UA pulsatility index (PI) and UA end-diastolic flow (EDF) were segmented into hourly periods during surgery, and the lowest values were averaged for analysis. Umbilical vein maximum velocity was measured in the fetoscopic cohort. At each timepoint at which FHR was recorded, maternal heart rate and systolic and diastolic blood pressure were measured., Results: Fetal bradycardia occurred in 4/22 (18.2%) cases of open closure and 21/46 (45.7%) cases of fetoscopic closure (P = 0.03). FHR decreased gradually in both cohorts after administration of general anesthesia and decreased further during surgery. FHR was significantly lower during hour 2 of surgery in the fetoscopic-repair cohort compared with the open-repair cohort. The change in FHR from baseline in the final stage of fetal surgery was significantly more pronounced in the fetoscopic-repair cohort compared with the open-repair cohort (mean, -32.4 (95% CI, -35.7 to -29.1) bpm vs -23.5 (95% CI, -28.1 to -18.8) bpm; P = 0.002). Abnormal UA-EDF (defined as absent or reversed EDF) occurred in 3/22 (13.6%) cases in the open-repair cohort and 23/46 (50.0%) cases in the fetoscopic-repair cohort (P = 0.004). There were no differences in UA-EDF or UA-PI between closure techniques at the individual stages of assessment., Conclusions: We observed a decrease in FHR and abnormalities in UA Doppler parameters during both open and fetoscopic spina bifida closure. Fetal bradycardia was more prominent during fetoscopic closure following hhCO 2 insufflation, but FHR recovered after cessation of hhCO 2 . Changes in FHR and UA Doppler parameters during in-utero spina bifida closure were transient, no cases required emergency delivery and no fetoscopic closure was converted to open closure. These observations should inform algorithms for the perioperative management of fetal bradycardia associated with in-utero spina bifida closure. © 2024 International Society of Ultrasound in Obstetrics and Gynecology., (© 2024 International Society of Ultrasound in Obstetrics and Gynecology.)

Objective: To evaluate whether in fetuses with open spina bifida (OSB) the tentorium can be seen to be displaced downwards and vertically oriented by the time of the 11-13-week scan and whether this is reflected in an alteration of the brainstem-tentorium (BST) angle., Methods: The study population was recruited between 2015 and 2020 from three fetal medicine referral centers and comprised a control group and a study group of pregnancies with OSB. The control group was recruited prospectively and included singleton pregnancies with a normal sonographic examination after first-trimester combined screening for chromosomal abnormalities and normal outcome. The study group was selected retrospectively and included all cases with OSB between 2015 and 2020. All cases underwent detailed ultrasound assessment at 11 + 0 to 13 + 6 weeks' gestation. The position of the torcular Herophili (TH) was identified in the midsagittal view of the fetal brain with the use of color Doppler and was considered as a proxy for the insertion of the tentorium on the fetal skull. The BST angle was calculated in the same view and was compared between the two groups., Results: Sixty normal fetuses were included in the control group and 22 fetuses with OSB in the study group. In both groups, the BST angle was found to be independent of gestational age or crown-rump length (P = 0.8815, R 2  = 0.0003861 in the controls, and P = 0.2665, R 2  = 0.00978 in the OSB group). The mean BST angle was 48.7 ± 7.8° in controls and 88.1 ± 1.18°, i.e. close to 90°, in fetuses with OSB. Comparison of BST-angle measurements between the control group and cases with OSB showed a statistically significant difference (P = 0.0153). In all fetuses with OSB, the downward displacement of the TH and tentorium was clearly visible at the 11-13-week scan., Conclusions: In fetuses with OSB, the BST angle is significantly larger than in normal controls, with the tentorium being almost perpendicular to the brainstem. This sign confirms the inferior displacement of the tentorium cerebelli with respect to its normal insertion on the occipital clivus as early as the first trimester of pregnancy and is useful in the diagnosis of Chiari-II malformation at this early stage. In fetuses with OSB, the low position of the tentorium and TH is clearly visible, even subjectively, at the 11-13-week scan. © 2021 International Society of Ultrasound in Obstetrics and Gynecology., (© 2021 International Society of Ultrasound in Obstetrics and Gynecology.)

Objective: Spina bifida (SB) is a congenital birth defect defined as a failure of the neural tube formation during the embryonic development phase. Fetoscopic repair of SB is a novel treatment technique that allows to close spinal defect early and prevent potential neurological and psychomotor complications., Case Report: We present a case report of a 32-year-old-multigravida whose fetus was diagnosed with lumbosacral myelomeningocele at 23rd week. Fetoscopic closure of MMC was performed at 26 weeks. At 32 weeks, due to premature amniorrhexis and placental abruption, an emergency C-section was performed. Newborn's psychomotor development was within normal limits., Conclusion: Although intrauterine treatment has an increased risk of premature labor, placental abruption, prenatal closure is associated with improved postnatal psychomotor development. Prenatal surgery decreases the risk of Arnold-Chiari II malformation development and walking disability. Fetoscopic closure of SB is becoming a choice for treatment with beneficial outcomes for mother and fetus., Competing Interests: Conflicts of interest The authors state no conflict of interest., (Copyright © 2021. Published by Elsevier B.V.)

Objective: To modify the current neural tube defect (NTD) classification for fetal medicine specialists, and to investigate the impact of prenatal ultrasound conus medullaris position screening on the detection rate of closed spinal dysraphism and pregnancy outcomes., Materials and Methods: The clinical data of 112 patients prenatally diagnosed with neural tube defects in Taiji clinic from 2008 to 2018 were retrospectively analyzed. All cases were classified following the modified classification. We compared the detection rate before and after introducing the conus medullaris screening and pregnancy outcomes for NTD types., Results: Closed spinal dysraphism type prevailed in our sample (43.8%). The median gestational age at the time of detection for cranial dysraphism was 13.3 weeks, open spinal dysraphism was 22.0 weeks, and closed spinal dysraphism was 22.6 weeks. All cranial dysraphism (n = 43) and open spinal dysraphism cases (n = 20) had pregnancies terminated. For closed spinal dysraphism Class 1, the live-birth rate was 100.0% in the cases without other anomalies and 33.3% in the cases with other anomalies, respectively (X 2  = 17.25, p < 0.001). Similarly, for Class 2, pregnancy continuation rate was 50.0% in cases without other anomalies and 20.0% in cases with other anomalies, yet it failed to reach statistical significance (X 2  = 0.9, p = 0.524)., Conclusion: Our case series may help to improve early screening and prenatal diagnosis of NTDs. Modified classification is adjusted for use in ultrasound fetal care facilities, which could be used for predicting pregnancy outcome. We suggest promoting first-trimester anatomical screening in order to make an earlier diagnosis and therefore provide better prenatal care for open spinal dysraphism cases in the era of intrauterine repair. Our findings imply that the use of fetal conus medullaris position as a marker for closed spinal dysraphism improves the detection rate and would unlikely lead to a higher termination rate., Competing Interests: Declaration of competing interest The author(s) have no conflicts of interest relevant to this article., (Copyright © 2021. Published by Elsevier B.V.)

We describe a case series of imaging findings of 4 patients who underwent spinal dysraphisms repair in utero with novel patch material, cryopreserved human umbilical cord, in our institution. In our study, the prenatal and postnatal magnetic resonance imaging and ultrasound are reviewed and showed cord tethering and syrinx progression in all cases. Our report is the first description of magnetic resonance imaging and ultrasound findings in the context of using this novel patch in severe cases of spinal dysraphisms.

We present a case-based review of the first five percutaneous fetoscopic in-utero spina bifida repair procedures undertaken in the UK. Our focus is on implications of anaesthesia and analgesia for the mother and fetus, provision of uterine relaxation and fetal immobilisation while providing conditions conducive to surgical access. Minimising risks for fetal acidosis, placental and fetal hypoperfusion, maternal and fetal sepsis and maternal fluid overload were the foremost priorities. We discuss optimisation strategies undertaken to ensure fetal and maternal well-being under anaesthesia, shortcomings in the current approach, and possible directions for improvement., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Fetal intervention has progressed in the past two decades from experimental proof-of-concept to practice-adopted, life saving interventions in human fetuses with congenital anomalies. This progress is informed by advances in innovative research, prenatal diagnosis, and fetal surgical techniques. Invasive open hysterotomy, associated with notable maternal-fetal risks, is steadily replaced by less invasive fetoscopic alternatives. A better understanding of the natural history and pathophysiology of congenital diseases has advanced the prenatal regenerative paradigm. By altering the natural course of disease through regrowth or redevelopment of malformed fetal organs, prenatal regenerative medicine has transformed maternal-fetal care. This review discusses the uses of regenerative medicine in the prenatal diagnosis and management of three congenital diseases: congenital diaphragmatic hernia, lower urinary tract obstruction, and spina bifida., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

The mechanisms underlying mammalian neural tube closure remain poorly understood. We report a unique cellular process involving multicellular rosette formation, convergent cellular protrusions, and F-actin cable network of the non-neural surface ectodermal cells encircling the closure site of the posterior neuropore, which are demonstrated by scanning electron microscopy and genetic fate mapping analyses during mouse spinal neurulation. These unique cellular structures are severely disrupted in the surface ectodermal transcription factor Grhl3 mutants that exhibit fully penetrant spina bifida. We propose a novel model of mammalian neural tube closure driven by surface ectodermal dynamics, which is computationally visualized., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Objective: To determine whether the presence of a myelomeningocele (MMC) sac and sac size correlate with compromised lower-extremity function in fetuses with open spinal dysraphism., Methods: A radiology database search was performed to identify cases of MMC and myeloschisis (MS) diagnosed prenatally in a single center from 2013 to 2017. All cases were evaluated between 18 and 25 weeks. Ultrasound reports were reviewed for talipes and impaired lower-extremity motion. In MMC cases, sac volume was calculated from ultrasound measurements. Magnetic resonance imaging reports were reviewed for hindbrain herniation. The association of presence of a MMC sac and sac size with talipes and impaired lower-extremity motion was assessed. Post-hoc analysis of data from the multicenter Management of Myelomeningocele Study (MOMS) randomized controlled trial was performed to confirm the study findings., Results: In total, 283 MMC and 121 MS cases were identified. MMC was associated with a lower incidence of hindbrain herniation than was MS (80.9% vs 100%; P < 0.001). Compared with MS cases, MMC cases with hindbrain herniation had a higher rate of talipes (28.4% vs 16.5%, P = 0.02) and of talipes or lower-extremity impairment (34.9% vs 19.0%, P = 0.002). Although there was a higher rate of impaired lower-extremity motion alone in MMC cases with hindbrain herniation than in MS cases, the difference was not statistically significant (6.6% vs 2.5%; P = 0.13). Among MMC cases with hindbrain herniation, mean sac volume was higher in those associated with talipes compared with those without talipes (4.7 ± 4.2 vs 3.0 ± 2.6 mL; P = 0.002). Review of the MOMS data demonstrated similar findings; cases with a sac on baseline imaging had a higher incidence of talipes than did those without a sac (28.2% vs 7.5%; P = 0.007)., Conclusions: In fetuses with open spinal dysraphism, the presence of a MMC sac was associated with fetal talipes, and this effect was correlated with sac size. The presence of a larger sac in fetuses with open spinal dysraphism may result in additional injury through mechanical stretching of the nerves, suggesting another acquired mechanism of injury to the exposed spinal tissue. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd., (Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.)

Fetal spina bifida, the most common nonlethal birth defect of the central nervous system, results in substantial neurologic morbidity. The unified theory describes the complex relationship between local spinal lesions and development of Chiari 2 malformation, contributing to hydrocephalus. Prenatal ultrasonography reliably allows diagnosis, but fetal MR imaging is an important complement to identify additional brain abnormalities. Fetal surgery improves neurologic and motor outcomes, but various approaches, either open hysterotomy or minimally invasive to the uterus, carry substantial obstetric risks. Optimization of the fetoscopic approach aims to minimize maternal and obstetric risks, but data regarding longer-term outcomes are awaited., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Spina bifida (SB) is a complex disorder of failed neural tube closure during the first month of human gestation, with a suspected etiology involving multiple gene and environmental interactions. GPR161 is a ciliary G-protein coupled receptor that regulates Sonic Hedgehog (Shh) signaling. Gpr161 null and hypomorphic mutations cause neural tube defects (NTDs) in mouse models. Herein we show that several genes involved in Shh and Wnt signaling were differentially expressed in the Gpr161 null embryos using RNA-seq analysis. To determine whether there exists an association between GPR161 and SB in humans, we performed direct Sanger sequencing on the GPR161 gene in a cohort of 384 SB patients and 190 healthy controls. We identified six rare variants of GPR161 in six SB cases, of which two of the variants were novel and did not exist in any databases. Both of these variants were predicted to be damaging by SIFT and/or PolyPhen analysis. The novel GPR161 rare variants mislocalized to the primary cilia, dysregulated Shh and Wnt signaling and inhibited cell proliferation in vitro. Our results demonstrate that GPR161 mutations cause NTDs via dysregulation of Shh and Wnt signaling in mice, and novel rare variants of GPR161 can be risk factors for SB in humans.

Purpose: We sought to examine donor mesenchymal stem cell (MSC) kinetics after transamniotic stem cell therapy (TRASCET) in experimental spina bifida., Methods: Pregnant Sprague-Dawley dams exposed to retinoic acid for the induction of fetal neural tube defects received volume-matched intra-amniotic injections on gestational day 17 (E17; term=E22): either amniotic fluid MSCs (afMSCs) labeled with a luciferase reporter gene (n=78), or luciferase protein alone (n=66). Samples from twelve organ systems from each surviving fetus with spina bifida (total n=60) were screened via microplate luminometry at term., Results: Donor afMSCs were identified exclusively in the placenta, umbilical cord, spleen, bone marrow, hip bones, defect, and brain. Luminometry was negative in control fetuses receiving luciferase alone (p<0.001). Signal intensity in relative light units (RLUs) was moderately correlated between the defect and the hip bones (rho=0.38, p=0.048), and between the placenta and the brain (rho=0.40, p=0.038)., Conclusions: Amniotic mesenchymal stem cells engraft to specific sites after concentrated intra-amniotic injection in the setting of spina bifida. A hematogenous route encompassing the bone marrow as well as distant central nervous system homing are fundamental constituents of cell trafficking. These findings must be considered during eventual patient selection for transamniotic stem cell therapy in the prenatal management of spina bifida., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Failure of neural tube closure leads to neural tube defects (NTDs), common congenital abnormalities in humans. Among the genes whose loss of function causes NTDs in mice, Grainyhead-like3 (Grhl3) is essential for spinal neural tube closure, with null mutants exhibiting fully penetrant spina bifida. During spinal neurulation Grhl3 is initially expressed in the surface (non-neural) ectoderm, subsequently in the neuroepithelial component of the neural folds and at the node-streak border, and finally in the hindgut endoderm. Here, we show that endoderm-specific knockout of Grhl3 causes late-arising spinal NTDs, preceded by increased ventral curvature of the caudal region which was shown previously to suppress closure of the spinal neural folds. This finding supports the hypothesis that diminished Grhl3 expression in the hindgut is the cause of spinal NTDs in the curly tail, carrying a hypomorphic Grhl3 allele. Complete loss of Grhl3 function produces a more severe phenotype in which closure fails earlier in neurulation, before the stage of onset of expression in the hindgut of wild-type embryos. This implicates additional tissues and NTD mechanisms in Grhl3 null embryos. Conditional knockout of Grhl3 in the neural plate and node-streak border has minimal effect on closure, suggesting that abnormal function of surface ectoderm, where Grhl3 transcripts are first detected, is primarily responsible for early failure of spinal neurulation in Grhl3 null embryos., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Neural tube defects (NTDs) are among the most common and severe congenital malformations of the central nervous system. Animal studies have shown that apoptosis is involved in the development of NTDs. However, little evidence is available from human studies. We aim to examine the level of apoptosis and expression of apoptosis-regulating proteins of human terminated fetuses., Methods: A total of 37 NTD cases and 21 controls from pregnancy terminations were recruited. Tissues of the central nervous system were obtained through autopsy. Apoptosis of neuroepithelial cells was examined by terminal deoxynucleotidyl transferase-mediated deoxyuridinetriphosphate nick end-labeling (TUNEL) assay. Expression of PAX3, p53, and caspase 3/8/9 in central nervous tissue was measured using Western blotting., Results: More TUNEL-positive apoptosis cells were observed in the central nervous tissue of NTD cases than those of controls (p < 0.05). In spinal cord tissue, lower PAX3 expression, higher p53 expression, and increased levels of cleaved caspase 3(17kD) and cleaved caspase 8 (18kD) were found in anencephaly cases but not in spina bifida cases when compared with controls. In brain tissue, levels of PAX3 were significantly reduced in both encephalocele and spina bifida subtypes; the expression levels of cleaved caspase 3(17 kD) of encephalocele cases and cleaved caspase 8(47/45 kD) in spina bifida cases were higher than in controls; no difference was found in the expression of p53 or caspase 9 between NTDs and controls., Conclusion: These findings provide some evidence that excessive apoptosis in fetal central nervous tissues may be associated with the development of human NTDs. Birth Defects Research 109:1596-1604, 2017. © 2017 Wiley Periodicals, Inc., (© 2017 Wiley Periodicals, Inc.)

Background: Platelet-derived growth factor receptor alpha (PDGFRα) is a cell-surface receptor tyrosine kinase for platelet-derived growth factors. Correct timing and level of Pdgfra expression is crucial for embryo development, and deletion of Pdgfra caused developmental defects of multiple endoderm and mesoderm derived structures, resulting in a complex phenotypes including orofacial cleft, spina bifida, rib deformities, and omphalocele in mice. However, it is not clear if deletion of Pdgfra at different embryonic stages differentially affects these structures., Purpose: To address the temporal requirement of Pdgfra in embryonic development., Methods: We have deleted the Pdgfra in Pdgfra-expressing tissues at different embryonic stages in mice, examined and quantified the developmental anomalies., Results: Current study showed that (i) conditional deletion of Pdgfra at different embryonic days (between E7.5 and E10.5) resulted in orofacial cleft, spina bifida, rib cage deformities, and omphalocele, and (ii) the day of Pdgfra deletion influenced the combinations, incidence and severities of these anomalies. Deletion of Pdgfra caused apoptosis of Pdgfra-expressing tissues, and developmental defects of their derivatives., Conclusion: Orofacial cleft, spina bifida and omphalocele are among the commonest skeletal and abdominal wall defects of newborns, but their genetic etiologies are largely unknown. The remarkable resemblance of our conditional Pdgfra knockout embryos to theses human congenital anomalies, suggesting that dysregulated PDGFRA expression could cause these anomalies in human. Future work should aim at defining (a) the regulatory elements for the expression of the human PDGFRA during embryonic development, and (b) if mutations / sequence variations of these regulatory elements cause these anomalies.

Purpose: To describe the association of anorectal malformation (ARM) and spinal dysraphism (SD) in terms of impact on the management of SD and embryogenetic implications., Methods: Patients with SD associated with (A) or without (B) ARM were included. The two groups were further divided into operated on (A1/B1) or not (A2/B2) for SD. Groups A and B were compared for type of SD (embryogenetic classification) and prevalence of neurosurgery; Groups A1 vs. A2 for type of ARM (Wingspread classification); Groups A1 vs. B1 for age at neurosurgery, neurophysiology, and clinical symptoms., Main Results: One hundred twenty-one patients with SD, 83 with and 38 without ARM were consecutively treated (1999-2015). Group A was associated only with SDs developing after primary neurulation, corresponding to the period of cloacal septation and organogenesis (p = 0.0007). Untethering surgery was significantly less frequent in Group A (p < 0.0001 and p = 0.04, respectively). Higher ARMs were not associated with increased risk for neurosurgery. No other significant differences were detected., Conclusions: In our series, ARMs were associated only with SD developing after primary neurulation, suggesting a single insult leading to both SD and the associated ARM. Neurosurgery is indicated less frequently in patients with ARM-associated SD, despite the similar preoperative clinical features.

Aim: The purpose of this study was to determine the normal length of the brainstem (BS) in Korean fetuses and to evaluatethe usefulness of the routine measurement of BS size in the first trimester of pregnancy for the early detection of spina bifida., Material and Methods: A total of 2,621 normal singleton pregnant Korean women at 10+6 to 13+6 weeks of gestation were selected for this retrospective cross-sectional study. Ultrasonography was used to measure the length of the longest vertical depth diameter of the BS and brainstem-occipital bone (BSOB) in order to obtain the BS to BSOB ratio., Results: The best indicators for spina bifida ranged from 1.00±0.24 mm to 4.70±0.46 mm for the BS and from 2.90±0.36 mm to 8.50±0.92 mm for the BSOB. For the gestational period, BS (R=0.70) and BSOB (R=0.81) values were considered statistically significant (p<.0001). The value of the BS to BSOB ratio was <1.0 in normal fetuses, and was not correlated with the gestational age., Conclusion: Measurement of BS and BSOB diameter in the first trimester is thought to provide the best reference marker for evaluating the posterior brain for diagnosis of spina bifida.

Objective: We investigated the expression of microRNA-124a and its methylation status in the spinal cords of rats with congenital spina bifida versus rats with normal fetuses., Methods: Real-time quantitative reverse transcription-polymerase chain reaction was used to compare the expression of microRNA-124a in the spinal cords of 42 rats with all-trans retinoic acid induced congenital spina bifida and 42 rats with normal fetuses. The DNA methylation status in the promoter region of miRNA-124a was detected using methylation specific-PCR., Results: Compared with rats with normal fetuses, expression of microRNA-124a was significantly decreased in rats with congenital spina bifida fetuses. The percentages of spinal cords with DNA hypermethylation in the microRNA-124a promoter were 81% and 14% in the congenital spina bifida and normal control groups, respectively. The difference was statistically significant. Further apoptosis testing revealed increased apoptosis cell numbers in the congenital spina bifida samples. Meanwhile, the phosphorylated mitogen-activated protein kinase protein expression level dramatically decreased in the congenital spina bifida samples., Conclusion: Aberrant DNA methylation was responsible for down-regulation of microRNA-124a by regulating the mitogen-activated protein kinase pathway, suggesting that microRNA-124a is a potential diagnostic biomarker in congenital spina bifida.

Background: Spina bifida is a multifactorial congenital malformation of the central nervous system. The aim of this study was to ascertain the relevance of cell death/proliferation balance in human spina bifida and to assess autophagy distribution and levels during embryo-fetal development in neural tissue., Methods: Five human cases with myelomeningocoele were compared with 10 healthy human controls and LC3 protein expression was also analyzed in mouse embryos. Cell death was evaluated using TUNEL (terminal deoxynucleotidyl transferase-mediated deoxyuridinetriphosphate nick end-labeling) assay; cell proliferation was studied by counting Ki67-positive cells, and autophagy was assessed by observing the presence of LC3 punctuate dots., Results: Comparing human cases and controls (13 to 21 weeks of gestation), we observed a significant increase in TUNEL-positive cells in human spina bifida associated with a significantly decreased proliferation rate, indicating an alteration of the physiological cell rate homeostasis. LC3 distribution was found to be spatiotemporally regulated in both human and murine embryo-fetuses: in early pregnancy a diffuse and ubiquitous LC3 signal was detected. After neural tube closure, an intense LC3-positive signal, normally associated to extra energy requirement, was confined to the Lissauer's tract, the dorsolateral spinal zone containing centrally projecting axons from dorsal root ganglia, at any medullar levels. LC3 signal disappeared from 12 weeks of gestation., Conclusion: In conclusion, this study confirms the fundamental role of cell death/proliferation balance during central nervous system development and reports the changing expression of LC3 protein in mouse and human neural tube. Birth Defects Research (Part A) 106:104-113, 2016. © 2015 Wiley Periodicals, Inc., (© 2015 Wiley Periodicals, Inc.)

Objective: To identify a patch system to repair surgically created spina bifida in a sheep model for its efficacy in healing the skin defect, protecting the underlying spinal cord and reducing the Chiari II malformation., Methods: Spina bifida was created surgically in 16 fetuses from eight timed-pregnant sheep at gestational age of 75 days. Two fetuses did not survive the procedure. Repeat hysterotomy was performed at 95 days' gestation to cover the defect with either biocellulose film with underwater adhesive (BCF-adhesive) (n = 7) or human umbilical cord with suture (HUC-suture) (n = 7). Three fetuses without formation of the defect served as reference controls. The skin healing was examined by direct visualization after a planned Cesarean section at term, followed by histological analysis using hematoxylin and eosin and Masson's trichrome stains. Mid-sagittal sections of the fetal cranium and upper cervical spine were analyzed by a pediatric neuroradiologist who was blinded to the type of patch received., Results: Three fetuses that received the BCF-adhesive and six fetuses that received the HUC-suture survived to term for final analysis. As a result of dislodgment of the BCF-adhesive, all spina bifida defects repaired using BCF-adhesive were not healed and showed exposed spinal cord with leakage of cerebrospinal fluid. In contrast, all spinal defects repaired by HUC-suture were healed with complete regrowth of epidermal, dermal and subdermal tissue components, with no exposed spinal cord. The maximal skin wound width was 21 ± 3.6 mm in the BCF-adhesive group but 3 ± 0.8 mm in the HUC-suture group (P < 0.001). The spinal cord area (P = 0.001) and the number of anterior horn cells (P = 0.03) was preserved to a greater degree in the HUC-suture group than in the BCF-adhesive group, whilst psammoma bodies, signifying neuronal degeneration, were only observed in the BCF-adhesive group. Anatomic changes, indicative of Chiari II malformation, were seen in all three fetuses of the BCF-adhesive group but in none of the HUC-suture group (P < 0.01)., Conclusion: Cryopreserved umbilical cord graft is a promising regenerative patch for intrauterine repair of spina bifida., (Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.)

Purpose: We sought to study the impact of trans-amniotic stem cell therapy (TRASCET) in the Chiari-II malformation in experimental spina bifida., Methods: Sprague-Dawley fetuses (n=62) exposed to retinoic acid were divided into three groups at term (21-22 days gestation): untreated isolated spina bifida (n=21), isolated spina bifida treated with intra-amniotic injection of concentrated, syngeneic, labeled amniotic fluid mesenchymal stem cells (afMSCs) on gestational day 17 (n=28), and normal controls (n=13). Analyses included measurements of brainstem and cerebellar placement on high resolution MRI and histology. Statistical comparisons included ANOVA., Results: In parallel to the expected induced coverage of the spina bifida in the afMSC-treated group (P<0.001), there were statistically significant differences in brainstem displacement across the groups (P<0.001), with the highest caudal displacement in the untreated group. Significant differences in cerebellar displacement were also noted, albeit less pronounced. Pairwise comparisons were statistically significant, with P=0.014 between treated and normal controls in caudal brainstem displacement and P<0.001 for all other comparisons. Labeled afMSCs were identified in 71% of treated fetuses., Conclusions: Induced coverage of spina bifida by TRASCET minimizes the Chiari-II malformation in the retinoic acid rodent model, further suggesting it as a practical alternative for the prenatal management of spina bifida., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Gastrulation is the process in which the three germ layers are formed that contribute to the formation of all major tissues in the developing embryo. We here review mouse genetic models in which defective gastrulation leads to mesoderm insufficiencies in the embryo. Depending on severity of the abnormalities, the outcomes range from incompatible with embryonic survival to structural birth defects, such as heart defects, spina bifida, or caudal dysgenesis. The combined evidence from the mutant models supports the notion that these congenital anomalies can originate from perturbations of mesoderm specification, epithelial-mesenchymal transition, and mesodermal cell migration. Knowledge about the molecular pathways involved may help to improve strategies for the prevention of major structural birth defects., (© 2014 Wiley Periodicals, Inc.)

Background: Neural tube closure defects (NTDs) are among the most common congenital malformation in human, typically presenting in liveborns as spina bifida. At least 240 gene mutations in mouse are known to increase the risk of NTD. There is a growing appreciation that environmental factors significantly contribute to NTD expression, and that NTDs likely arise from complex gene-environment interactions. Because maternal folic acid supplementation reduces human NTD risk in some populations by 60 to 70%, it is likely that NTD predisposition is often associated with a defect in folate-dependent one-carbon metabolism. A comprehensive, untargeted metabolic survey of NTD-associated changes in embryo metabolism would provide a valuable test of this assumption. We sought to establish a metabolic profiling platform that is capable of broadly assessing metabolic aberrations associated with NTD-promoting gene mutations in early-stage mouse embryos., Methods: A liquid chromatography/mass spectrometry-based untargeted metabolite profiling platform was used to broadly identify significant differences in small molecule levels (50-1000 Da) in NTD-affected embryonic day (E) 9.5 mouse embryos (Lrp6(-) (/) (-) ) versus unaffected (Lrp6(+/+) ) control embryos., Results: Results provide proof-of-principal feasibility for the broad survey of the metabolome of individual E9.5 mouse embryos and identification of metabolic changes associated with NTDs and gene mutations. Levels of 30 different metabolites were altered in association with Lrp6 gene deletion. Some metabolites link to folate-dependent one-carbon transfer reactions, as anticipated, while others await structure elucidation and pathway integration., Conclusion: Whole-embryo metabolomics offers the potential to identify metabolic changes in genetically determined NTD-prone embryos., (© 2014 Wiley Periodicals, Inc.)

Open spina bifida or myelomeningocele (SBM) is the most common birth defect involving the central nervous system, second only in incidence to congenital cardiac disease. Outcomes in this disorder were poor until the mid-20th century, when modern neurosurgical techniques (closing the lesion and treating hydrocephalus) and treatment for the neuropathic bladder addressed the major causes of mortality, although SBM may still be poorly treated in the developing world. Initial management - or mismanagement - has a profound impact on survival and long-term quality of life.

Background: This study aimed to assess the feasibility of single-access fetal endoscopy (SAFE) for the management of myelomeningocele (MMC) using intrauterine carbon dioxide as a distension medium in a sheep model., Methods: This prospective experimental case-control study investigated 12 lamb fetuses that had a myelomeningocele-like defect surgically created on the 75th day of gestation. Four fetuses remained untreated (control group), and eight fetuses had MMC repair using two fetoscopic approaches with carbon dioxide used to distend the amniotic cavity. A collagen patch was placed over the defect and secured with surgical sealant. Four animals had a two-port fetoscopic procedure, and four animals had SAFE. Clinical and pathologic studies were performed after delivery., Results: This study confirmed the validity of the animal MMC model. None of the control animals was able to stand or walk, and all had a significant defect in the lumbar area with continuous leakage of cerebrospinal fluid, ventriculomegaly, and a Chiari-II malformation. All the treated animals, independently of the number of ports used in the repair, were able to walk and had a closed defect with resolution of the Chiari malformation., Conclusions: The SAFE patch and glue coverage of surgically created fetal MMC is feasible and effective in restoring gross neurologic function in the fetal lamb model.

The pentalogy of Cantrell, a rare syndrome, consists of the defects in the anterior diaphragm, diaphragmatic pericardium, lower sternum and supraumbilical abdominal wall, along with congenital cardiac abnormalities. Till date, only few patients with full spectrum of this syndrome have been reported with only 2 cases showing associated exencephaly and spinal dysraphism. We report extremely rare association of complete pentalogy of Cantrell syndrome with exencephaly and spinal dysraphism on antenatal sonogram and autopsy in a 18 weeks fetus of a 19 year-old primi gravida female.

Background and Purpose: Sprengel's deformity, a rare congenital malformation of the scapula, may be observed in combination with spinal dysraphism. The co-occurrence of these malformations suggests an unknown shared etiology. Therefore, we reviewed the medical records of eight children presenting with both malformations and performed a review of the literature., Patients and Methods: Databases from four university medical centers were searched for children presenting between 1992 and 2012 with spinal dysraphism and a Sprengel's deformity., Conclusion: The combination of spinal dysraphism and Sprengel's deformity is rare, and is associated with segmentation defects of the spine and ribs. Although the etiology of both spinal dysraphism and Sprengel's deformity remains unclear, all deformities of the spine, ribs, and shoulder might result from a common genetic defect affecting somitogenesis.

Cases of spina bifida alone and in association with ventriculomegaly represent important but different malformations according to clinical characteristics. In our study, we analyzed the data on pregancies terminated because of isolated cases (n=307) and ventriculomegaly-associated cases (n=372) of spina bifida. In spina bifida cases in association with hydrocephalus, positive obstetric history was found approximately 1.5 times more frequently than in the isolated ones. The incidence of positive genetic history was nearly two-fold in the latter cases. In isolated cases of spina bifida, associated malformations were more common than in cases of spina bifida and ventriculomegaly together. The most frequent associated malformations were those of the urogenital system (in cases of spina bifida: 11.1%; in cases of SB+V: 9.14%). The risk of recurrence of SB+V is significantly higher than that of isolated SB (8.9% vs. 2.1%). It can be concluded that positive genetic history is more common in cases of isolated spina bifida. Malformations out of the nervous system are more commonly observed in cases of isolated spina bifida. During the prenatal diagnostics of spina bifida, sonography must focus on malformations of the urogenital system., (Copyright © 2013 Elsevier GmbH. All rights reserved.)

Purpose: To compare two-dimensional ultrasonography (2DUS) and magnetic resonance imaging (MRI) for assessing brain and spine parameters in fetuses with spina bifida., Methods: A cross-sectional study was conducted on 15 fetuses with spina bifida (one with encephalocele, four with rachischisis and 10 with myelomeningocele). The size of the atrium of the lateral ventricle, percentage shortening of the cerebellum, degree of compromising of the first vertebra and total number of vertebras affected by herniation were assessed. The MRI examination was performed not more than 7 days after the 2DUS. To compare and correlate the parameters from the two techniques, the paired Student's t test and intraclass correlation coefficient (ICC) were used. To assess the correlations of atrium measurements from 2DUS and MRI with other parameters, Pearson's correlation coefficient (r) was used., Results: No significant difference was observed in any of the means of the parameters assessed using the two techniques (p > 0.05). Both 2DUS and MRI seemed to present satisfactory reliability in measurements on the size of the atrium of the lateral ventricle and the first vertebra affected (ICC = 0.88 and 0.75, respectively). Measurements on the atrium of the lateral ventricle from 2DUS correlated better with the other parameters than did measurements from MRI., Conclusions: In fetuses with spina bifida, 2DUS and MRI present similar results, but measurements on the atrium of the lateral ventricle from 2DUS correlated better with the other parameters.

Neural tube defects (NTDs) are common birth defects of complex etiology. Family and population-based studies have confirmed a genetic component to NTDs. However, despite more than three decades of research, the genes involved in human NTDs remain largely unknown. We tested the hypothesis that rare copy number variants (CNVs), especially de novo germline CNVs, are a significant risk factor for NTDs. We used array-based comparative genomic hybridization (aCGH) to identify rare CNVs in 128 Caucasian and 61 Hispanic patients with non-syndromic lumbar-sacral myelomeningocele. We also performed aCGH analysis on the parents of affected individuals with rare CNVs where parental DNA was available (42 sets). Among the eight de novo CNVs that we identified, three generated copy number changes of entire genes. One large heterozygous deletion removed 27 genes, including PAX3, a known spina bifida-associated gene. A second CNV altered genes (PGPD8, ZC3H6) for which little is known regarding function or expression. A third heterozygous deletion removed GPC5 and part of GPC6, genes encoding glypicans. Glypicans are proteoglycans that modulate the activity of morphogens such as Sonic Hedgehog (SHH) and bone morphogenetic proteins (BMPs), both of which have been implicated in NTDs. Additionally, glypicans function in the planar cell polarity (PCP) pathway, and several PCP genes have been associated with NTDs. Here, we show that GPC5 orthologs are expressed in the neural tube, and that inhibiting their expression in frog and fish embryos results in NTDs. These results implicate GPC5 as a gene required for normal neural tube development.

We sought to determine whether neural stem cells (NSCs) can be isolated from the amniotic fluid in the setting of neural tube defects (NTDs), as a prerequisite for eventual autologous perinatal therapies. Pregnant Sprague-Dawley dams (n=62) were divided into experimental (n=42) and control (n=20) groups, depending on prenatal exposure to retinoic acid for the induction of fetal NTDs. Animals were killed before term for analysis (n=685 fetuses). Amniotic fluid samples from both groups underwent epigenetic selection for NSCs, followed by exposure to neural differentiation media. Representative cell samples underwent multiple morphological and phenotypical analyses at different time points. No control fetus (n=267) had any structural abnormality, whereas at least one type of NTD developed in 52% (217/418) of the experimental fetuses (namely, isolated spina bifida, n=144; isolated exencephaly, n=24; or a combination of the two, n=49). Only amniotic samples from fetuses with a NTD yielded cells with typical neural progenitor morphology and robust expression of both Nestin and Sox-2, primary markers of NSCs. These cells responded to differentiation media by displaying typical morphological changes, along with expression of beta-tubulin III, glial fibrillary acidic protein, and/or O4, markers for immature neurons, astrocytes, and oligodendrocytes, respectively. This was concurrent with downregulation of Nestin and Sox-2. We conclude that the amniotic fluid can harbor disease-specific stem cells, for example, NSCs in the setting of experimental NTDs. The amniotic fluid may be a practical source of autologous NSCs applicable to novel forms of therapies for spina bifida.

Objective: Neural stem cells (NSCs) may promote spinal cord repair in fetuses with experimental spina bifida. We sought to determine the fate of amniotic-derived NSCs (aNSCs) after simple intra-amniotic injection in a syngeneic model of spina bifida., Methods: Fetal neural tube defects were induced on 20 pregnant Lewis dams by prenatal administration of retinoic acid. Ten dams served as amniotic fluid donors for epigenetic isolation of aNSCs, which were expanded and labeled with 5-bromo-2'-deoxyuridine. The remaining 10 dams received intra-amniotic injections of the processed aNSCs, blindly in all their fetuses (n = 37) on gestational day 17 (term = E21-22). Fetuses with spina bifida underwent screening for the presence of donor aNSCs in the spinal cord at term., Results: Donor cells were identified in 93.3% of the animals with spina bifida, selectively populating the neural placode, typically in clusters, retaining an undifferentiated morphology, and predominantly on exposed neural surfaces, though some were detected deeper in neighboring neural tissue., Conclusions: The amniotic cavity can serve as a route of administration of NSCs in experimental spina bifida. Simple intra-amniotic delivery of NSCs may be a practical adjuvant to regenerative strategies for the treatment of spina bifida., (Copyright © 2013 S. Karger AG, Basel.)

Objective: This paper aimed to determine the feasibility of identification and measurement reproducibility of intracranial translucency (IT) in our population., Methods: This is a prospective study in which five accredited operators attempted to identify and measure the IT during first-trimester sonographic screening for aneuploidy in 990 fetuses. The presence or absence of spina bifida was determined at the time of the second-trimester scan or after birth. Measurement reproducibility was assessed through intraclass correlation coefficient (ICC) on a subgroup of 150 fetuses., Results: Identification and measurement of the IT were possible in 961 (97%) cases. The mean IT anteroposterior diameter was 1.8 mm (SD ± 0.37; range 0.8-3.1), and the size increased linearly with advancing gestation (IT = 0.74 + 0.02 × crown-rump length; r(2) = 0.15, p < 0.0001). The only fetus with spina bifida in this series presented with absent IT. Intra-observer and inter-observer ICCs were 0.79 and 0.75, respectively (95% confidence intervals 0.72-0.84 and 0.67-0.81, respectively; both p < 0.001)., Conclusions: The IT increases linearly with increasing crown-rump length and seems to be of value in the first-trimester detection of spina bifida. It is easy to identify and measure and shows excellent intra-observer and inter-observer reproducibility measurements., (© 2012 John Wiley & Sons, Ltd.)

Although maternal intake of folic acid (FA) prevents neural tube defects in 70% of the population, the exact mechanism of prevention has not been elucidated. We hypothesized that FA affects neural stem cell (NSC) proliferation and differentiation. This hypothesis was examined in a folate-responsive spina bifida mouse model, Splotch (Sp(-/-)), which has a homozygous loss-of-function mutation in the Pax3 gene. Neurospheres were generated with NSCs from the lower lumbar neural tube of E10.5 wild-type (WT) and Sp(-/-) embryos, in the presence and absence of FA. In the absence of FA, the number of neurospheres generated from Sp(-/-) embryos compared with WT was minimal (P<0.05). Addition of FA to Sp(-/-) cultures increased the expression of a Pax3 downstream target, fgfr4, and rescued NSC proliferative potential, as demonstrated by a significant increase in neurosphere formation (P<0.01). To ascertain if FA affected cell differentiation, FA-stimulated Sp(-/-) neurospheres were allowed to differentiate in the continued presence or absence of FA. Neurospheres from both conditions expressed multi-potent stem cell characteristics and the same differentiation potential as WT. Further, multiple neurospheres from both WT and FA-stimulated Sp(-/-) cell cultures formed extensive synaptic connections. On the whole, FA-mediated rescue of neural tube defects in Sp(-/-) embryos promotes NSC proliferation at an early embryonic stage. FA-stimulated Sp(-/-) neurospheres differentiate and form synaptic connections, comparable to WT.

Objectives: To determine the position of the fetal conus medullaris during pregnancy in relation to the last vertebral body and to examine its use in detecting skin-covered spinal dysraphism., Methods: This was a retrospective study involving 300 consecutive ultrasound examinations between 15 weeks of gestation and term. Two operators independently assessed images of the spine to determine whether the conus medullaris and the last vertebral body could be visualized in a single image in a midsagittal plane. The distance between these two landmarks (the conus distance) was measured twice by both operators who were not aware of any previous measurements. Intra- and interobserver variability was assessed by 95% limits of agreement. Linear regression analysis was used to determine the relevant contributors to the conus distance and a normal range was computed based on the best-fit model. The normal results were compared with five cases of prenatally detected skin-covered spinal dysraphism., Results: In 84.7% of the 300 cases, both operators were able to visualize the conus medullaris and the last vertebral body. Ninety-five percent limits of agreement for the intraobserver variability in measurement of conus distance were ± 1.9 mm. For the interobserver variability, they were - 3.7 and 2.5 mm. We found a linear relationship between conus distance and gestational age, biparietal diameter and abdominal circumference. The strongest relationship was observed for femur length (conus distance = - 8.2 + femur length (mm)). In the five abnormal cases, conus distance was well below the 5(th) percentile., Conclusions: Determination of conus distance allows for an objective and feasible assessment of the conus medullaris position. This parameter promises to be useful in the prenatal detection of skin-covered spinal dysraphism., (Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.)

We present a pictorial review of MRI features of various closed spinal dysraphisms based on previously described clinicoradiological classification of spinal dysraphisms proposed. The defining imaging features of each dysraphism type are highlighted and a diagnostic algorithm for closed spinal dysraphisms is suggested.

Cranial neural tube defects (NTDs) occur in mice carrying mutant alleles of many different genes, whereas isolated spinal NTDs (spina bifida) occur in fewer models, despite being common human birth defects. Spina bifida occurs at high frequency in the Axial defects (Axd) mouse mutant but the causative gene is not known. In the current study, the Axd mutation was mapped by linkage analysis. Within the critical genomic region, sequencing did not reveal a coding mutation whereas expression analysis demonstrated significant up-regulation of grainyhead-like 2 (Grhl2) in Axd mutant embryos. Expression of other candidate genes did not differ between genotypes. In order to test the hypothesis that over-expression of Grhl2 causes Axd NTDs, we performed a genetic cross to reduce Grhl2 function in Axd heterozygotes. Grhl2 loss of function mutant mice were generated and displayed both cranial and spinal NTDs. Compound heterozygotes carrying both loss (Grhl2 null) and putative gain of function (Axd) alleles exhibited normalization of spinal neural tube closure compared with Axd/+ littermates, which exhibit delayed closure. Grhl2 is expressed in the surface ectoderm and hindgut endoderm in the spinal region, overlapping with grainyhead-like 3 (Grhl3). Axd mutants display delayed eyelid closure, as reported in Grhl3 null embryos. Moreover, Axd mutant embryos exhibited increased ventral curvature of the spinal region and reduced proliferation in the hindgut, reminiscent of curly tail embryos, which carry a hypomorphic allele of Grhl3. Overall, our data suggest that defects in Axd mutant embryos result from over-expression of Grhl2.

This article provides information regarding the etiology, pathogenesis, and skeletal manifestation of spina bifida or spinal dysraphisms. On the basis of a review of the medical literature, it addresses discrepancies in documentation and interpretation of spina bifida in paleopathology. Furthermore, it offers suggestions for use of universal terminology and highlights the difficulties in the specific diagnosis of dysraphisms in skeletal remains. In addition, the necessity of examining the entire skeleton for abnormalities to distinguish simple delay/failure of fusion of the posterior neural arches from other occult spinal dysraphisms is emphasized, as it is the need for stratification of the sample by age and sex when reporting frequencies of sacral spina bifida occulta., (Copyright © 2010 Wiley-Liss, Inc.)

Objective: To determine whether in fetuses with open spina bifida at 11-13 weeks' gestation the frontomaxillary facial angle is decreased., Methods: The frontomaxillary facial angle was measured in 20 fetuses with open spina bifida and in 100 normal controls matched for crown-rump length (CRL) at 11 + 0 to 13 + 6 weeks and the values in the two groups were compared., Results: In the control group the frontomaxillary facial angle decreased significantly with CRL from a mean of 84.0 degrees at a CRL of 45 mm to 76.5 degrees at a CRL of 84 mm (SD, 3.26 degrees). In the spina bifida group the mean frontomaxillary facial angle, corrected for CRL, was 9.9 degrees lower than in the controls and it was below the 5(th) centile in 18 (90%) of the cases (P < 0.0001)., Conclusions: In fetuses with open spina bifida at 11-13 weeks' gestation the frontomaxillary facial angle is decreased and this measurement may be useful in early screening for this abnormality., ((c) 2010 ISUOG. Published by John Wiley & Sons, Ltd.)

Tethered cord syndrome (TCS) is a clinical condition of various origins that arises from tension on the spinal cord. Radiographic findings may include the conus medullaris in a lower than normal position, fatty infiltration of the filum terminale, lipomyelomeningocele, myelomeningocele, myelocystocele, meningocele, split cord malformations, dermal sinus, anorectal malformations, and intraspinal tumors. The clinical constellation of signs and symptoms associated with TCS may include dermatologic, urological, gastrointestinal, neurological, and orthopedic findings. The current review focuses on TCS by age group of the more common causes of the condition, including myelomeningocele, lipomyelomeningocele, as well as the adult presentation of occult TCS. Pertinent review of the neuroembryology and normal anatomical position of the conus medullaris is included.

Background: The technical performance of minimally invasive fetoscopic surgery may be severely hindered by poor visualization of intra-amniotic contents. Partial amniotic carbon dioxide insufflation (PACI) allows the visual limitations of operating within the fluid environment to be overcome., Patients and Methods: When amniotic fluid exchange failed to improve fetoscopic visualization, PACI was attempted during 37 fetoscopic procedures between 17 + 5 and 33 + 2 weeks of gestation. PACI was attempted with filtered carbon dioxide using a commercially available insufflator via one to three trocars that were percutaneously introduced into the amniotic cavity. The maximum pressure during PACI was limited by the maximum insufflation pressure (30 mmHg) generated by the insufflator. Improvement of fetoscopic visualization as well as technical, maternal, and fetal safety aspects surrounding PACI were analyzed., Results: PACI could successfully be instituted in 36 of the 37 procedures. In one case, when in the presence of increased uterine tone the opening pressure exceeded the maximum insufflation pressure of the insufflator, the strategy was abandoned. In all cases where PACI could be instituted successfully, the approach offered far superior visualization of the fetoscopic procedure than would have been possible within amniotic fluid. Acute or chronic maternal or fetal complications were observed in only one case (intraoperative membrane rupture)., Conclusion: PACI greatly improves fetal visualization during fetoscopic interventions when fetoscopy within fluid meets with difficulties. Continued assessment of its benefits, risks, and safety margins at specialist centers is required.

Improvements in magnetic resonance (MR) imaging now permit diagnostic images of the fetus to be obtained. Ultrasound remains vital in all aspects of fetal imaging but MR provides a useful second line imaging test. Its value is best researched in fetal central nervous system disorders but it can be applied in other areas too. This pictorial review shows many of the commonly encountered problems. The pictures have a powerful impact on parental understanding. Future research must involve determination of the prognosis of abnormalities found at MR.

Objective: To determine which prenatal ultrasound findings can predict survival and mental and motor functioning in children with spina bifida., Methods: Prenatal ultrasound examinations of all liveborn children who were prenatally diagnosed with spina bifida between 1997 and 2002 at the University Medical Centre, Utrecht (n = 41) were retrospectively reviewed for lesion level, head circumference, ventriculomegaly, scoliosis and talipes. These measures were correlated with postnatal anatomical (as assessed by magnetic resonance imaging (MRI)) and functional lesion levels, survival and motor and mental outcome at 5 years of age. The capacity of prenatal ultrasonography to determine lesion level was also assessed in all fetuses diagnosed with spina bifida from 2006-2007 (n = 18)., Results: Nineteen infants died before the age of 5 years. Multivariate regression analysis showed that higher lesion level and head circumference > or = the 90th percentile on prenatal ultrasound examination were independent predictors of demise (P < 0.05 and P = 0.01, respectively). None of the ultrasound features was a predictor of motor or mental functioning. Ultrasound predicted anatomical lesion level within one level of the postnatal findings in 50% of the first cohort and 89% of the second cohort (P < 0.01). The level of the anatomical lesion as assessed by postnatal MRI differed from the functional lesion by as many as six vertebral levels., Conclusions: Lesion level and head circumference on prenatal ultrasound are predictive of survival in children with spina bifida. No predictors were found for mental or motor function at the age of 5 years.

The mammalian Sonic hedgehog (Shh) signalling pathway is essential for embryonic development and the patterning of multiple organs. Disruption or activation of Shh signalling leads to multiple birth defects, including holoprosencephaly, neural tube defects and polydactyly, and in adults results in tumours of the skin or central nervous system. Genetic approaches with model organisms continue to identify novel components of the pathway, including key molecules that function as positive or negative regulators of Shh signalling. Data presented here define Tulp3 as a novel negative regulator of the Shh pathway. We have identified a new mouse mutant that is a strongly hypomorphic allele of Tulp3 and which exhibits expansion of ventral markers in the caudal spinal cord, as well as neural tube defects and preaxial polydactyly, consistent with increased Shh signalling. We demonstrate that Tulp3 acts genetically downstream of Shh and Smoothened (Smo) in neural tube patterning and exhibits a genetic interaction with Gli3 in limb development. We show that Tulp3 does not appear to alter expression or processing of Gli3, and we demonstrate that transcriptional regulation of other negative regulators (Rab23, Fkbp8, Thm1, Sufu and PKA) is not affected. We discuss the possible mechanism of action of Tulp3 in Shh-mediated signalling in light of these new data.