Closed Spina Bifida Research Articles

Detection of non-cardiac fetal abnormalities on ultrasound at 11-14 weeks: systematic review and meta-analysis.

To assess the diagnostic accuracy of two-dimensional ultrasound at 11-14 weeks' gestation as a screening test for individual fetal anomalies and to identify factors impacting on screening performance. This was a systematic review and meta-analysis that was developed and registered with PROSPERO (CRD42018111781). MEDLINE, EMBASE, Web of Science Core Collection and the Cochrane Library were searched for studies evaluating the diagnostic accuracy of screening for 16 predefined, non-cardiac, congenital anomalies considered to be of interest to the early anomaly scan. We included prospective and retrospective studies from any healthcare setting conducted in low-risk, mixed-risk and unselected populations. The reference standard was the detection of an anomaly on postnatal or postmortem examination. Data were extracted to populate 2 × 2 tables and a random-effects model was used to determine the diagnostic accuracy of screening for the predefined anomalies (individually and as a composite). Secondary analyses were performed to determine the impact on detection rates of imaging protocol, type of ultrasound modality, publication year and index of sonographer suspicion at the time of scanning. Post-hoc secondary analysis was conducted to assess performance among studies published during or after 2010. Risk of bias assessment and quality assessment were undertaken for included studies using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. From 5684 citations, 202 papers underwent full-text review, resulting in the inclusion of 52 studies comprising 527 837 fetuses, of which 2399 were affected by one or more of the 16 predefined anomalies. Individual anomalies were not equally amenable to detection on first-trimester ultrasound: a high (> 80%) detection rate was reported for severe conditions, including acrania (98%), gastroschisis (96%), exomphalos (95%) and holoprosencephaly (88%); the detection rate was lower for open spina bifida (69%), lower urinary tract obstruction (66%), lethal skeletal dysplasias (57%) and limb-reduction defects (50%); and the detection rate was below 50% for facial clefts (43%), polydactyly (40%) and congenital diaphragmatic hernia (38%). Conditions with a low (< 30%) detection rate included bilateral renal agenesis (25%), closed spina bifida (21%), isolated cleft lip (14%) and talipes (11%). Specificity was > 99% for all anomalies. Secondary analysis showed that detection improved with advancing publication year, and that the use of imaging protocols had a statistically significant impact on screening performance (P < 0.0001). The accurate detection of congenital anomalies using first-trimester ultrasound is feasible, although detection rates and false-positive rates depend on the type of anomaly. The use of a standardized protocol allows for diagnostic performance to be maximized, particularly for the detection of spina bifida, facial clefts and limb-reduction defects. Highlighting the types of anomalies amenable to diagnosis and determining factors enhancing screening performance can support the development of first-trimester anomaly screening programs. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Comparison between MRI and the Combination of 2D and 3D US in the Prenatal Diagnosis of Closed Spina Bifida

Introduction: Closed spina bifida (CSB) is a rare condition with a challenging prenatal diagnosis. Herein, we assess the conventional two-dimensional (2D) ultrasound (US) combined with three-dimensional (3D) ultrasound (US) and magnetic resonance imaging (MRI) in the prenatal diagnosis of CSB. Methods: In this retrospective study, we included 20 cases of fetal CSB confirmed by postnatal MRI, post-mortem pathological examination, or postpartum surgery. Prenatal 2D US complemented with the 3D US was performed in all fetuses to evaluate the characteristics of the conus, vertebral arch, and scoliosis. Moreover, MRI was performed to establish the split vertebrae, with or without a bulging mass. Thereafter, we compared the performance of the US and MRI. Results: Diagnosis accuracy of US was comparable with MRI (70% vs. 75%, κ = 0.62); US detected more cases with interpediculate distance ≥95% (55% vs. 35%, κ = 0.22) than MRI. On the other hand, MRI had a superior capacity for identifying vertebral arch fissures (20% vs. 35%, κ = 0.39). MRI and ultrasound had good agreement in the conus medullaris (65% vs. 70%, κ = 0.42) and scoliosis (45% vs. 35%, κ = 0.59). Both US and MRI detected 1 (5.0%) case with “lemon sign” and “banana sign.” The missed diagnosis rates of US and MRI were 15% (3/20) and 5% (1/20), respectively. The misdiagnosis rates of US and MRI were 15.0% (3/20) and 20.0% (4/20), respectively. Conclusion: Both MRI and 2D US combined with the 3D US had excellent performance in prenatal diagnosis of CSB.

Investigation on the status of ultrasonic prenatal screening for fetal closed spina bifida.

Investigation on the status of ultrasonic prenatal screening for fetal closed spina bifida.

The role of routine first-trimester ultrasound screening for central nervous system abnormalities: a longitudinal single-center study using an unselected cohort with 3-year experience

BackgroundTo evaluate the role of a standardized first-trimester scan in screening different kinds of central nervous system malformations and to report a 3-year experience from a tertiary center using an unselected cohort.MethodsThis was a retrospective analysis of prospectively collected data from a single center evaluating first-trimester scans with predesigned standardized protocols performed between 1 May 2017 and 1 May 2020, involving 39,526 pregnancies. All pregnant women underwent a series of prenatal ultrasound scans at 11–14, 20–24, 28–34 and 34–38 weeks of gestation. Abnormalities were confirmed by magnetic resonance imaging, postmortem examination or trained ultrasound professionals. Pregnancy outcomes and some postnatal follow-up were obtained from maternity medical records and telephone calls.ResultsA total of 38,586 pregnancies included in the study. The detection rates of CNS anomalies by ultrasound in the first, second, third and late third trimester were 32%, 22%, 25%, and 16%, respectively. And there were 5% of CNS anomalies missed by prenatal ultrasound. In the first-trimester scan, we diagnosed all cases of exencephaly, anencephaly, alobar holoprosencephaly and meningoencephalocele, and some cases of posterior cranial fossa anomalies (20%), open spina bifida (67%), semilobar holoprosencephaly (75%) and severe ventriculomegaly (8%). Vein of Galen aneurysmal malformation, closed spina bifida, lobar holoprosencephaly, intracranial infection, arachnoid cyst, agenesis of the corpus callosum, cysts of the septum pellucidum and isolated absence of the septum pellucidum were never detected during the first trimester. The abortion rates of fetal CNS anomalies detected by first-trimester scan, second-trimester scan, and third- trimester scan were 96%, 84% and 14%, respectively.ConclusionsThe study showed that almost 1/3 of central nervous system anomalies were detected by the standard first-trimester scan and these cases were associated with a high rate of abortion. Early screening for fetal abnormalities gives parents more time for medical advice and safer abortion if needed. It is therefore recommended that some major CNS anomalies should be screened in the first trimester. The standardized anatomical protocol, consisting of four fetal brain planes, were recommended for routine first trimester ultrasound screening.

EP29.19: Early diagnosis of an atypical phenotype of closed spina bifida

EP29.19: Early diagnosis of an atypical phenotype of closed spina bifida

Avoiding the antenatal counselling faux pas: bridging the gap between prenatal prognostication and postnatal outcome of closed spina bifida.

Closed spina bifida (CSB) is rare in prenatal literature, and various lesions are grouped under this broad nosological entity CSB, leading to confusing and misleading prognostic conclusions. This is a retrospective observational cohort study of prenatally detected CSB cases using two-dimensional ultrasound, complemented by three-dimensional ultrasonography and foetal MRI in indicated cases, from October 2014 to October 2021 in a tertiary-level single centre. The most common upper vertebral level of CSB was lumbar in 66.6% (10/15). The sub-classification of lesions based on prenatal ultrasound showed an agreement in 53% of the cases. Sixty percent had associated abnormalities identified postnatally, the most common being anorectal malformation seen in 33.3%. On postnatal follow-up, 46.6% had bowel incontinence and bladder dysfunction, and 33.3% developed lower limb deformities. All CSBs do not have a uniformly favourable prognosis. The prognosis of CSB depends on the pathological type, the presence of associated abnormalities and the management.

First‐Trimester Cranial Ultrasound Markers of Open Spina Bifida

To evaluate cranial ultrasound markers during a first-trimester routine ultrasound examination for screening for open spina bifida (OSB). Midsagittal and axial images of the fetal head obtained from fetuses with spina bifida and unaffected control fetuses at 11 weeks to 13 weeks 6 days were analyzed retrospectively. The observed markers of the posterior brain included the 4- versus 3-line view, the brain stem (BS)-to-brain stem-occipital bone (BSOB) distance ratio (BS/BSOB), the position relationship between the maxillo-occipital (MO) line and the midbrain-BS junction, and the crash sign status. This study included 9 OSB cases, 2 closed spina bifida (CSB) cases, and 200 unaffected controls. Eight of 9 OSB cases had informative midsagittal views of the head. The 3-line view (abnormal) and BS/BSOB greater than 1 (abnormal) were observed in 87.5% (7 of 8) and 100% (8 of 8), respectively. The midbrain-BS junction was below or nearly on the MO line (abnormal) in 100% (8 of 8). Seven of the cases had informative axial views of the head. The crash sign (abnormal) was observed in 85.7% (6 of 7). A 3-line view was seen in all of the cases that had a positive crash sign. Neither of the 2 cases of CSB and none of the controls had any of the 4 first-trimester intracranial ultrasound markers of OSB. The 4 first-trimester intracranial ultrasound markers investigated in this study appear to be very good markers of OSB, especially a BS/BSOB greater than 1 and an abnormal MO line. The crash sign and 3-line view were observed in the same fetus. In our study, these ultrasound findings were not helpful in CSB.

Fetal Open and Closed Spina Bifida on a Routine Scan at 11 Weeks to 13 Weeks 6 Days.

This study aimed to determine the sensitivity of a first-trimester routine scan in detecting spina bifida (SB) and evaluating the first-trimester intracranial signs. This retrospective study was a review of a prospectively collected database. All cases of SB diagnosed in a tertiary center from 2008 to 2015 were identified. The ultrasound images and medical records were reviewed. All cases of SB diagnosed prenatally were confirmed at birth or autopsy. A total of 24 cases of SB were diagnosed from 53,349 pregnancy cases. Except for 10 cases with a body stalk anomaly, craniorachischisis, or iniencephaly, 7 cases with open spina bifida (OSB) and 7 cases with closed spina bifida (CSB) were analyzed. The first-trimester detection rates were 100% (7 of 7) for OSB and 28.5% (2 of 7) for CSB. Eight cases were highly suspected of SB in the first trimester because of an abnormal appearance of the posterior brain; 3 were false-positive cases. Two isolated cases of OSB had first-trimester intracranial signs. An obliterated cisterna magna (CM) showed the highest sensitivity for OSB but low specificity. Two cases of OSB had no discernible landmark of intracranial translucency and the CM, and 4 showed normal intracranial translucency with an obliterated CM. All CSB cases were coupled with a normal hind brain except for 2 cases. A first-trimester routine scan has high sensitivity in screening for OSB. The CM may be the most sensitive intracranial sign.

Prenatal diagnosis of closed spina bifida: multicenter case series and review of the literature

Objective: Closed spina bifida (CSB) is an abnormality of the posterior arch formation in which the defect is covered by the skin, without protrusion of nervous tissue. The prenatal diagnosis of CSB is very difficult, rarely diagnosed antenatally.Methods: We present a multicenter case series of six prenatal diagnosis of CSB using two-dimensional (2D) ultrasonography complemented with three-dimensional (3D) ultrasonography and magnetic resonance imaging (MRI). All cases of prenatal diagnosis of CSB were confirmed in the postnatal period/termination of pregnancy by both clinical and/or imaging diagnosis (ultrasonography and MRI).Results: 2D ultrasonography allowed the prenatal diagnosis of six cases. We observed two cases of subcutaneous lipomas, two cases of meningoceles, one case of fibrolipomas, and one case of false-positive CSB (meningomyelocele). 3D ultrasonography using rendering mode was important in one case of meningocele (case# 3). Three cases were delivered at term and one of them was submitted to corrective surgery. All these three newborns were discharged from the hospital well and without neurologic signs. Termination of pregnancy was performed in three cases.Conclusion: During prenatal evaluation, detailed ultrasonographic assessment of the entire spine with the identification of the position and morphology of the conus medullaris and absence of cranial signs of spinal dysraphism are the most valuable sonographic clues for the diagnostic of the CSB.

P02.02: Multiplane and skeletal mode of 3D ultrasound for prenatal diagnosis of vertebral deformation and closed spina bifida

This study aimed to explore the value of multiplane and skeletal mode of 3D ultrasound for prenatal diagnosis of vertebral formation failure and closed spina bifida. This study included sonographic data from 22 fetuses suspected to have spine deformations. Three-dimensional reconstruction was performed on selected areas when spine malformation or conus medullaris lower than L3 was suspected. Multiplane of 3D ultrasound was used to analyse the type of vertebral deformation, and skeletal mode was to assess the location of vertebral deformation or conus medullaris. This study revealed vertebral deformation in 22 cases, including 6 cases of hemivertebrae, 3 cases of butterfly vertebrae, 3 cases of coronal cleft vertebra. Moreover , this study also revealed 10 cases of low-lying conus medullaris, which was closed spina bifida with 7 cases of spinal meningocle and 3 cases of caudal regression syndrome. Multiplane is helpful for determination of the type of vertebral formation failure. Skeletal mode is helpful for assessing the location of the spinal deformities in the developing fetus.

OP07.03: Prenatal evaluation of the conus medullaris position in normal fetuses and fetuses with closed spina bifida by using a new method: three‐dimensional ultrasound skeletal render mode combined with horizontal central line

OP07.03: Prenatal evaluation of the conus medullaris position in normal fetuses and fetuses with closed spina bifida by using a new method: three‐dimensional ultrasound skeletal render mode combined with horizontal central line

Cranial and cerebral signs in the diagnosis of spina bifida between 18 and 22 weeks of gestation: a German multicentre study.

The aim of this article is to study secondary cranial signs in fetuses with spina bifida in a precisely defined screening period between 18 + 0 and 22 + 0 weeks of gestation. On the basis of retrospective analysis of 627 fetuses with spina bifida, the value of indirect cranial and cerebral markers was assessed by well-trained ultrasonographers in 13 different prenatal centres in accordance with the ISUOG (International Society of Ultrasound in Obstetrics and Gynecology) guidelines on fetal neurosonography. Open spina bifida was diagnosed in 98.9% of cases whereas 1.1% was closed spina bifida. Associated chromosomal abnormalities were found in 6.2%. The banana and lemon signs were evident in 97.1% and 88.6% of cases. Obliteration of the cisterna magna was seen in 96.7%. Cerebellar diameter, head circumference and biparietal diameter were below the 5th percentile in chromosomally normal fetuses in 72.5%, 69.7% and 52%, respectively. The width of the posterior horn of the lateral ventricle was above the 95th percentile in 57.7%. The secondary cranial and cerebral signs were dependent on fetal chromosome status and width of the posterior horn. Biparietal diameter was also dependent on the chromosome status with statistical significance p = 0.0068. Pregnancy was terminated in 89.6% of cases. In standard measuring planes, lemon sign, banana sign and an inability to image the cistern magna are very reliable indirect ultrasound markers of spina bifida. © 2014 John Wiley & Sons, Ltd.

Accessory limb with myelomeningocele: a rare case challenging previously held beliefs

There have been previous reports of intra-scapular limbs associated with a closed spina bifida and this has led to a causative theory. It is thought that these dysraphic appendages could not occur with defects of primary neurulation. The authors present a rare case of this abnormality associated with a large open myelomeningocele in a 6-day-old infant presenting to a paediatric neurosurgical hospital in Uganda. The appendage was removed and the spina bifida closed. There was significant stigma associated with such abnormality in this region. The first reported co-existence of these two lesions challenges previously held beliefs regarding the embryological origin of intra-scapular dysraphic appendage.

Normal intracranial translucency and posterior fossa at 11–13 weeks' gestation in a fetus with closed spina bifida

Normal intracranial translucency and posterior fossa at 11–13 weeks' gestation in a fetus with closed spina bifida

Novel VANGL1 Gene Mutations in 144 Slovakian, Romanian and German Patients with Neural Tube Defects

Neural tube defects (NTDs) are a group of congenital malformations of the central nervous system occurring at an average rate of 1 per 1,000 human pregnancies worldwide. Numerous genetic and environmental factors are discussed to be relevant in their etiology. In mice, mutants in >200 genes including the planar cell polarity (PCP) pathway are known to cause NTDs, and recently, heterozygous mutations in the human VANGL1 gene have been described in a small subset of patients with NTDs. We performed a VANGL1 mutation analysis in 144 unrelated individuals with NTDs from Slovakia, Romania and Germany and identified 3 heterozygous missense mutations: c.613G>A (p.Gly205Arg) with an open spina bifida (lumbosacral meningomyelocele), c.557G>A (p.Arg186His) with a closed spina bifida (tethered cord and spinal lipoma) and c.518G>A (p.Arg173His) with an unknown NTD. The c.613G>A mutation was also found in a healthy sibling. None of the mutations were described previously. Findings support that heterozygous VANGL1 mutations represent hypomorphs or conditional mutants predisposing to NTDs and occur at a frequency of approximately 2.1% of open and closed spinal NTDs. The mutations (p.Arg173His, p.Arg186His, p.Gly205Arg) modified conserved regions of the VANGL1 protein and shared similarities with previously described mutants, providing further evidence for the presence of mutational hot spots in these patients.

21st World Congress on Ultrasound in Obstetrics and Gynecology, 18-22 September 2011, Los Angeles, USA: presentations and awards

21st World Congress on Ultrasound in Obstetrics and Gynecology, 18-22 September 2011, Los Angeles, USA: presentations and awards

Retrospective review of diagnostic performance of intracranial translucency in detection of open spina bifida at the 11–13‐week scan

To evaluate diagnostic performance of intracranial translucency (IT) for detection of open spina bifida and interobserver agreement for visualization of IT during the 11-13-week scan. A retrospective study was undertaken in a tertiary referral center. Two hundred 11-13-week scans for nuchal translucency, performed by sonographers certified by The Fetal Medicine Foundation, U.K., were reviewed independently for IT by two expert observers. When IT was not seen, the observers determined whether this was due to poor IT image quality or the presence of spina bifida. Discordant cases were reviewed by a third observer and the majority decision was used for analysis. All observers were blinded to individual pregnancy outcome and the number of cases with spina bifida. There were 191 normal fetuses, eight fetuses with open spina bifida and one with closed spina bifida (this case was excluded from analysis). IT was seen in 150 fetuses and all were normal. In six of the 49 cases in which IT was not seen, IT non-visibility was attributed to open spina bifida; among these cases, four fetuses had open spina bifida and two were normal. In the remaining 43 cases (including 39 normal fetuses), IT non-visibility was attributed to inadequate image quality. Sensitivity was 50% (4/8) and specificity was 99% (150/152). Concordance between the two observers concerning IT visibility was 79%, (κ = 0.47, representing moderate agreement). There was moderate interobserver agreement for visualization of IT on images obtained for nuchal translucency measurement at 11-13 weeks. When IT was confidently seen, open spina bifida could be excluded. However, non-visibility of IT correctly diagnosed only 50% of fetuses with open spina bifida.

Meningocele Due to Closed Spina Bifida Mimicking a Metastasis of Papillary Thyroid Carcinoma on Whole Body Radioactive Iodine Scan

Meningocele Due to Closed Spina Bifida Mimicking a Metastasis of Papillary Thyroid Carcinoma on Whole Body Radioactive Iodine Scan

OP03.05: Prenatal detection of closed spina bifida

Objectives: To determine the position of the conus medullaris during pregnancy in relation to the last vertebral body and to examine its use to detect skin covered, closed spinal bifida. Methods: Retrospective study involving 300 consecutive ultrasound examinations between 16 weeks of gestation and term. Two operators independently assessed the images of the spine on whether the conus medullaris and the last vertebral body were visualised in one image in a midsagittal plane. The distance (conus distance/CD) between these two landmarks was measured twice by both operators, who were not aware of any previous measurements. Intraand interobserver variability was assessed by 95% limits of agreement. Linear regression analysis was used to determine the relevant contributors to the CD 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. 95% limits of agreement for the intraobserver variability were ±1.9 mm. For the interobserver variability they were −3.7 and 2.5 mm. We found a linear relationship of CD to gestational age, biparietal diameter and abdominal circumference. The strongest relationship was observed for femur length (CD = −8.2+ × femur length). In the five abnormal cases, CD was well below the 5th percentile. Conclusions: The determination of CD allows for an objective and feasible assessment of the conus medullaris position. The parameter promises to be very useful for the prenatal detection of skin covered spinal dysraphism.

OP13.03: Prenatal findings and outcome of open and closed spina bifida: analysis of 164 cases

(FAPD/BPD, FLLD/BPD) and the perimeter and area for the HC (FPer/HC, FA/HC). The best curve to fit the relationships of the different variables with gestational age was identified and the changes in the absolute fontanelle size and of its relationship with the fetal head during gestation were analyzed. Results: A linear regression model fitted FLLD, FA, and all ratios, while a quadratic regression model fitted FAPD and FPer. The absolute size of the fontanelle significantly increased during the first half of pregnancy, until 26 weeks of gestation, to plateau or decrease thereafter. However, all ratios showed a significant negative correlation with advancing gestational age. Conclusions: This study suggests that the rapid growth of the fetal head, determined by the expansion of the brain, occurs faster than the ossification of the cranial bones and the anterior fontanelle. This determines an increase in the absolute size of the fontanelle despite the fact that its size relative to the whole volume of the fetal head is rapidly decreasing. It could be suggested that it is the fetal head that grows around the anterior fontanelle rather than the latter reducing in size during gestation. These data may be of help in understanding the mechanism behind an abnormal fontanelle development (delayed ossification or premature closure).