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

Multidisciplinary management of people with spina bifida across the lifespan

The average worldwide prevalence of neural tube defects (NTDs) is 1.0 per 1000 births. Its development is multifactorial due to genetic and non-genetic factors. Spina bifida (SB) is one of main representatives of NTD. The spinal cord lesion level is the main determinant of the level of paralysis, numbness, and difficulties with bladder/bowel functions. Myelomeningocele prenatal repair reduces hydrocephalus and hindbrain herniation and improves motor function. The severity of hydrocephalus is associated with poorer neurodevelopmental outcomes whether operated on prenatally or after birth. People with SB tend to have a lower IQ and cognitive difficulties. Early diagnosis, proactivity, and lifelong multidisciplinary follow-up are key protective issues. Invasive urological interventions should be considered in selected patients after failure of conservative treatment. Transition to adult care should be well planned as it is challenging. Health literacy is directly associated with success at transition. Sexuality and fertility should be addressed before/during puberty. Overall, the rates of fecal and urinary continence and skin breakdown increase with age, whereas the ability to ambulate declines with age. Bowel and urinary incontinence are independent predictors of lower health-related quality of life (HRQoL) in adults with SB. Bowel incontinence has negative impact on HRQoL regardless of frequency or amount. Long-term caregiver support should be offered at diagnosis. Survival at a mean of 50 years is poor, at 32%, due to central nervous system deaths, cancer, urological disease, and sepsis. Challenges to implementation of recommended practices exist, especially in low and middle-income countries.

Myelomeningocele: the evolution of care over the last 50 years

PURPOSE

Myelomeningocele (MMC) is one of the representative anomalies in the field of pediatric neurosurgery. During the 50 years of ISPN history, MMC had a tremendous changes in its incidence, clinical management and outcome with advanced understanding of its pathogenesis. We reviewed the changes in MMC during the period.

METHODS

We reviewed the literature review and collected our experiences.

RESULTS

During the 50 years, major changes happened in many aspects of MMC including incidence, pathoembryogenesis, folate deficiency, prevention, prenatal diagnosis, mode of delivery, treatment policy with ethical considerations, clinical treatment including fetal surgery, latex allergy, retethering, management outcome, multidisciplinary team approach, and socioeconomic and family issues.

CONCLUSIONS

There was a great advance in the management and research of MMC during the 50 years. It is a monumental achievement of pediatric neurosurgeons and colleagues of the related fields.

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.

Basic sonographic examination of the fetal brain at 11-13 weeks' gestation: Rationale for a simple and reliable four-step technique

The widespread incorporation of first-trimester scanning between 11 and 13 weeks' gestation has shifted from the screening of chromosomal abnormalities, mainly by measuring nuchal translucency thickness and visualization of the nasal bone, to a more detailed study of the fetal anatomy leading to early detection of several structural congenital anomalies. This goal can be improved by the routine and focused sonographic assessment of specific anatomic planes and the identification of distinctive landmarks that can help disclosing a particular, non-evident condition. In this article we present the basis for a basic, early examination of the fetal brain during screening using a four-step technique, which can be readily incorporated during the first-trimester scan. The technique includes the focused visualization of the cranial contour, choroid plexuses of the lateral ventricles and midline, aqueduct of Sylvius, brainstem, fourth ventricle, and the choroid plexus of the fourth ventricle. The rationale for this approach is presented and discussed.

Fetal Repair of Neural Tube Defects

Myelomeningocele is the most common congenital neurologic defect, and the only nonlethal disease addressed by fetal surgery. A randomized control trial has established amelioration of the Arnold-Chiari II malformation, reduced ventriculoperitoneal shunt rate, and improvement in distal neurologic function in patients that receive in utero repair. Long-term follow-up of these school-age children demonstrates the persistence of these effects. The use of stem cells in fetal repair is being investigated to further improve distal motor function.

Prenatal diagnosis and pregnancy outcome of major structural anomalies detectable in the first trimester: A population-based cohort study in the Netherlands

BACKGROUND

Prenatal diagnosis of several major congenital anomalies can be achieved in the first trimester of pregnancy.

OBJECTIVE

This study investigates the timing of diagnosis and pregnancy outcome of foetuses and neonates with selected structural anomalies in the Northern Netherlands over a 10-year period when the prenatal screening programme changed significantly, but no first-trimester anatomical screening was implemented.

METHODS

We performed a population-based retrospective cohort study with data from the EUROCAT Northern Netherlands database on pregnancies with delivery or termination of pregnancy for fetal anomaly (TOPFA) date between 2010 and 2019. The analysis was restricted to anomalies potentially detectable in the first trimester of pregnancy in at least 50% of cases, based on previously published data. These included: anencephaly, encephalocele, spina bifida, holoprosencephaly, tricuspid/pulmonary valve atresia, hypoplastic left heart, abdominal wall and limb reduction defects, lethal skeletal dysplasia, megacystis, multiple congenital anomalies. The primary outcome was the timing of diagnosis of each structural anomaly. Information on additional investigations, genetic testing and pregnancy outcome (live birth, TOPFA and foetal/neonatal death) was also collected.

RESULTS

A total of 478 foetuses were included; 95.0% (n = 454) of anomalies were detected prenatally and 5.0% (n = 24) postpartum. Among the prenatally detected cases, 31% (n = 141) were diagnosed before 14 weeks of gestation, 65.6% (n = 298) between 14-22 weeks and 3.3% (n = 15) after 22 weeks. Prenatal genetic testing was performed in 80.4% (n = 365) of cases with prenatally diagnosed anomalies, and the results were abnormal in 26% (n = 95). Twenty-one% (n = 102) of pregnancies resulted in live births and 62.8% (n = 300) in TOPFA. Spontaneous death occurred in 15.9% (n = 76) of cases: in-utero (6.1%, n = 29), at delivery (7.7%, n = 37) or in neonatal life (2.1%, n = 10).

CONCLUSION

Major structural anomalies amenable to early diagnosis in the first trimester of pregnancy are mostly diagnosed during the second trimester in the absence of a regulated first-trimester anatomical screening programme in the Netherlands and are associated with TOPFA and spontaneous death, especially in cases with underlying genetic anomalies.

Qualitative and quantitative study of fetal posterior fossa during the first trimester in a Chinese population

Background

To establish the normal reference ranges for parameters related to the fetal posterior fossa in the first trimester (11 ~ 13+6 weeks of gestation) and to analyze the relationship between them and crown-rump length (CRL) among the Chinese population.

Methods

Singleton pregnancies of 11 ~ 13⁺⁶ weeks (CRL:45 ~ 84 mm) with both parents from China were randomly selected from January 2021 to November 2021. The related parameters of the posterior fossa including cisterna magna (CM), intracranial translucency (IT), brain stem (BS), brain stem to the occipital bone (BSOB), and brain stem/brain stem to occipital bone (BS/BSOB) were evaluated and measured in nuchal translucency (NT) mid-sagittal section clearly by an experienced sonographer (operator 1). To assess the reproducibility of the measurements, we randomly selected 50 pregnant women. According to the blind method, operators 1 and 2 respectively screened and measured relevant parameters. In addition, operator 1 examined and measured relevant parameters again 2 h after the first.

Results

This study included 1663 fetuses. All fetuses can clearly show the three spaces of the fetal posterior fossa. The ICCs (95% CI) of intra-operator reproducibility of CM, IT, BS, BSOB, BS/BSOB were 0.981 (0.952 ~ 0.991, P < 0.001), 0.929 (0.866 ~ 0.961, P < 0.001), 0.970 (0.946 ~ 0.983, P < 0.001), 0.991 (0.974 ~ 0.996, P < 0.001), 0.939 (0.892 ~ 0.965, P < 0.001), respectively; The ICCs (95% CI) of inter-operator reproducibility 0.926 (0.860 ~ 0.960, P < 0.001), 0.810 (-0.083 ~ 0.940, P < 0.001), 0.820 (0.645 ~ 0.904, P < 0.001), 0.804 (0.656 ~ 0.888, P < 0.001), 0.772 (0.599 ~ 0.871, P < 0.001), respectively. There was a linear correlation between CRL and the parameters related to the posterior fossa (CM, IT, BS, BSOB, BS/BSOB). CM (mm) = -1.698 + 0.532 × CRL (cm) (r = 0.829, P < 0.001); IT (mm) = 0.701 + 0.179 × CRL (cm) (r = 0.548, P < 0.001); BS (mm) = 0.403 + 0.349 × CRL (cm) (r = 0.716, P < 0.001); BSOB (mm) = -0.277 + 0.719 × CRL (cm) (r = 0.829, P < 0.001); BS/BSOB = 0.747—0.021 × CRL (cm) (r = 0.196, P < 0.001).

Conclusions

Qualitative and quantitative assessment of the fetal posterior fossa structure was feasible in the first trimester. We constructed the normal reference ranges of CM, IT, BS, BSOB, and BS/BSOB. Furthermore, CM, IT, BS, and BSOB were positively correlated with CRL, but BS/BSOB was negatively correlated with CRL.

Evaluation of sensitivity and accuracy of maternal serum alpha fetoprotein to the diagnosis of open spina bifida in comparison with sonographic findings of open spina bifida and Chiari II malformation in pregnant women

Background

NTD is one of the most important problems of the nervous system and the second fetal anomaly that is associated with high mortality and morbidity. Therefore, its prenatal diagnosis is very important. AFP has a high false positive, which reduces its diagnostic value, so the discovery of ultrasound findings in OSB is very important and can replace AFP testing.

Results

4 patients with positive OSB were detected and their diagnosis was confirmed during pathological follow-up (100% diagnostic accuracy) and the rest of the patients with high AFP (51 patients) were negative for OSB. Therefore, the diagnostic accuracy of AFP during statistical analysis was about 7%, which is a very low value.

Conclusion

According to the results of this study, IT, BS, BSOB, BS/BSOB ultrasound criteria in the first screening and decreased BPD and ventriculomegaly in the second screening ultrasound in OSB diagnosis have a higher diagnostic value than the AFP laboratory level. It should pay more attention to MS-AFP results in OSB screening.

Sacral Spina Bifida Occulta: A Frequency Analysis of Secular Change

Substantial relaxation of natural selection beginning around 1900 changed the mutation/selec­tion balance of modern genetic material, producing an increase in variable anatomical structures. While multiple structures have been affected, the temporal increase in variations of the sacrum, specifically, ‘Sa­cral Spina Bifida Occulta,’ have been reliably demonstrated on a localised scale. Calculation of largescale frequency has been hindered by the localised nature of these publications, the morphological variability of this variation, and potential pathological associations, which have produced divergent classifications, and conflicting reported rates of occurrence. A systematic review of the reported literature was conducted to provide an objective analysis of Sacral Spina Bifida Occulta frequency from 2500 BCE to the present. This review was designed to compensate for observed inconsistencies in reporting and to ascertain, for the first time, the temporal trajectory of this secular trend. A systematic review of Sacral Spina Bifida Occulta lit­erature was conducted through the strict use of clinical meta-analysis criteria. Publications were retrieved from four databases: PubMed, Embase, the Adelaide University Library database, and Google Scholar. Data were separated into three historical groups, (1 = <1900, 2 = 1900 to 1980 and 3 = >1980), and frequency outcomes compared, to determine temporal rates of occurrence. A total of 39/409 publications were included in the final analysis, representing data for 16,167 sacra, spanning a period of 4,500 years. Statistically significant results were obtained, with total open S1 frequen­cy increasing from 2.34%, (79 to 1900CE), to 4.80%, (1900 to 1980CE) and to 5.43% (>1980CE). These increases were significant at p<0.0001, with Chi-squared analysis. A clear secular increase in the global frequency of Sacral Spina Bifida Occulta has been demonstrated from 1900 to the present. This research provides a novel and adaptable framework for the future assessment of variation distribution, with impor­tant implications for the fields of biological anthropology and bioarchaeology.

Pediatric Spina Bifida and Spinal Cord Injury

Pediatric spina bifida (SB) and spinal cord injury (SCI) are unfortunately common in our society, and their unique findings and comorbidities warrant special consideration. This manuscript will discuss the epidemiology, pathophysiology, prevention, and management strategies for children growing and developing with these unique neuromuscular disorders. Growth and development of the maturing child places them at high risk of spinal cord tethering, syringomyelia, ascending paralysis, pressure injuries, and orthopedic abnormalities that must be addressed frequently and judiciously. Similarly, proper neurogenic bladder and neurogenic bowel management is essential not just for medical safety, but also for optimal psychosocial integration into the child’s expanding social circle.

Could Lumbar Lordosis Angle Be A Predictor of Functionality in Children with Spina Bifida? A Cross-Section Study

Aims: This study aimed to investigate the relationship between lumbar lordosis angle (LLA) and trunk functions, sitting balance, functional independence, and lesion level in children with spina bifida (SB).Methods: Thirty children with SB were included. LLA was measured with a flexible ruler. The Pediatric Functional Reach Test (PRT), Trunk Impairment Scale (TIS), Functional Independence Measure for Children (WeeFIM), and International Myelodysplasia Study Group Criteria were used to evaluate sitting balance, trunk functions, functional independence, and motor lesion level respectively. The correlations were performed by using Spearman's correlation test.Results: There were significant correlations between the LLA and PRT, TIS, and WeeFIM results. Also, a significant correlation was found between the LLA and lesion level (p < .05).Conclusions: The development of the LLA in the normal range should be supported in rehabilitation approaches aiming to increase sitting balance, functional independence, and trunk functions in children with SB.Abbreviations: SB: Spina Bifida; LLA: Lumbar Lordosis Angle; MMS: Meningomyelocele; WeeFIM: Functional Independence Measure for Children; TIS: Trunk Impairment Scale; PRT: Pediatric Functional Reach Test.

Normal fetal development of the cervical, thoracic, and lumbar spine: A postmortem study based on magnetic resonance imaging

OBJECTIVE

Before evaluating spinal pathology, it is essential to have knowledge of the normal spinal development at different gestational ages. This study aims to characterize normal spinal growth in human fetuses during the second and third trimesters.

METHODS

Postmortem 3.0 T magnetic resonance imaging (MRI) was performed on 55 fetuses at 17-42 gestational weeks by using three-dimensional T2-weighted sequences. Morphological changes and quantitative measurements of the fetal spine were assessed. The correlation between centrum ossification center volume (COCV) and gestational age was investigated.

RESULTS

The cervical, thoracic, and lumbar COCVs showed a positive relationship with gestational age (p < 0.05). No gender differences were found in the volumetric development of the cervical, thoracic, and lumbar centrum ossification centers (COCs). The average volumetric growth rate per COC was larger in the lumbar spine than in the cervical and thoracic spine. The L1-L5 COCVs also showed a linear positive relationship with gestational age.

CONSULTS

Postmortem 3.0 T MRI clearly demonstrated spinal changes in external contour and internal structure with gestational age. These findings expand our understanding of the early growth pattern of the human spine and could be further used to assess the developmental conditions of the fetal spine.

Open intrauterine repair of spina bifida aperta: Historical aspects, current availability, and clinical outcomes from the Latin American Spina Bifida Consortium

OBJECTIVE

To determine the historical aspects, current availability, and clinical outcomes of open intrauterine repair of spina bifida aperta (IRSBA) in Spanish-speaking Latin American countries.

METHODS

Cases were collected from centers with at least 2 years of experience and a minimum of 10 open IRSBA interventions by December 2020. Clinical variables were compared to the results of the Management of Myelomeningocele Study (MOMS) trial.

RESULTS

Clinical experience with 314 cases from seven centers was reviewed. Most cases (n = 189, 60.2%) were performed between 24 and 25.9 weeks' gestation. Delivery at less than 30 weeks' gestation occurred in 36 cases (11.5%) and the overall perinatal mortality rate was 5.4% (17 of 314). The rate of maternal complications was low, including the need for blood transfusion (n = 3, 0.9%) and dehiscence or a thin uterine scar (n = 4, 1.3%). No cases of maternal death were recorded. Fifteen neonates required additional surgical repair of the spinal defect (4.8%) and 63 of 167 infants (37.7%) required a cerebrospinal fluid diversion procedure. Only two of the seven centers reported preliminary experience with fetoscopic IRSBA.

CONCLUSIONS

Clinical experience and outcomes were within the expected results reported by the MOMS trial. There is still very limited experience with fetoscopic IRSBA in this part of the world.

Prenatal intracranial hypotension syndrome: new insights into the mechanisms of fenestration of septi pellucidi and ventriculomegaly in fetuses with open spinal dysraphism

OBJECTIVE

To study the prevalence of abnormalities of the septi pellucidi (SP) in a cohort of fetuses with open spinal dysraphism (OSD) and to determine whether this condition is secondary to obstructive ventriculomegaly and, therefore, part of the natural history of prenatal intracranial hypotension (PICH) syndrome.

METHODS

Magnetic resonance imaging (MRI) studies from fetuses with OSD were analyzed. The SP were assessed using axial and coronal T2-weighted images of the fetal brain and classified as intact, partially absent, or completely absent. Additionally, the correlation between the presence or absence of the SP and the size of the lateral ventricles, degree of cerebellar tonsillar herniation, collapse of the fourth ventricle, and interpeduncular angle was investigated.

RESULTS

A total of 32 fetuses with OSD were studied. Mean gestational age at the time of the fetal MRI was 25.5 ± 3.9 weeks (range, 19-35) and mean ventricular size was 16.2 ± 4.2 mm (range, 8-26). Twenty-three (71.9%) fetuses had cerebellar tonsillar herniation. The IPA was completely collapsed in 23 cases (71.9%), reduced in seven (21.9%), and unreadable in two (6.3%). Twenty (62.5%) fetuses presented with intact SP, 10 (31.3%) with partially absent SP (incomplete fenestration), and two (6.3%) with completely absent SP (complete fenestration). Fenestration of the SP correlated significantly with the degree of ventriculomegaly (Pearson's correlation coefficient =0.459; p = .01). However, there was no correlation with the IPA, collapse of the fourth ventricle, and cerebellar tonsillar herniation.

CONCLUSIONS

More than one-third of the fetuses with OSD had fenestration of the SP. The most probable etiology is increased intraventricular pressure leading to local necrosis of the SP. As fenestration of the SP is a secondary event associated with PICH syndrome, this condition should not be considered a contraindication for intrauterine repair of the spinal defect. Instead, it should be seen as an indicator of the severity of the intraventricular pressure.

Interpeduncular angle: A new parameter for assessing intracranial hypotension in fetuses with spinal dysraphism

OBJECTIVE

To investigate the role of the interpeduncular angle (IPA) as a new indicator of intracranial hypotension in fetuses with open spinal dysraphism (SD).

METHODS

Two groups of fetuses undergoing magnetic resonance imaging (MRI) examination were identified. The study group included fetuses with open SD (n = 21), while the control group included fetuses with a normal brain and spine (n = 43). Two observers retrospectively evaluated axial T2-weighted images of the brain and the IPA was identified and measured. Other features of the Chiari II malformation were also evaluated in the study group and correlated with the IPA.

RESULTS

The average value (±SD) of the IPA for the study and control groups was 9.8° ± 18.5° and 60.2° ± 5.9°, respectively. The intergroup analysis of the IPA measurements revealed a statistically significant difference between the groups (p < 0.005). Brainstem slumping or cerebellar tonsillar descent, collapse of the fourth ventricle, and ventriculomegaly also had a significant correlation with a lower IPA (p = 0.001).

CONCLUSION

Measuring the IPA may be a useful technique for assessing the degree of intracranial hypotension in fetuses with open SD. This technique can also detect less severe cases of prenatal intracranial hypotension, even before cerebellar tonsillar descent. The lower IPA in fetuses with open SD further supports the theory that cerebrospinal fluid leakage, and not traction, is the underlying cause of Chiari II malformation.

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

OBJECTIVES

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

A first-trimester routine scan has high sensitivity in screening for OSB. The CM may be the most sensitive intracranial sign.

Perspectives on urological care in spina bifida patients

Spina bifida (SB) is a neurogenetic disorder with a complex etiology that involves genetic and environmental factors. SB can occur in two major forms of open SB or SB aperta and closed SB or SB occulta. Myelomeningocele (MMC), the most common neural tube defects (NTDs), occurs in approximately 1 in 1,000 births. Considering non-genetic factors, diminished folate status is the best-known factor influencing NTD risk. The methylenetetrahydrofolate reductase (MTHFR) gene has been implicated as a risk factor for NTDs. The primary disorder in the pathogenesis of MMC is failed neural tube closure in the embryonic spinal region. The clinical manifestation of SB depends on clinical type and severity. SB can be detected in the second trimester using ultrasound which will reveal specific cranial signs. The management of MMC traditionally involves surgery within 48 h of birth. Prenatal repair of MMC is recommended for fetuses who meet maternal and fetal Management of Myelomeningocele Study (MOMS) specified criteria. Urological manifestations of SB include urinary incontinence, urolithiasis, sexual dysfunction, renal dysfunction, and urinary tract infection. Renal failure is among the most severe complications of SB. The most important role of the urologist is the management of neurogenic bladder. Medical management with clean intermittent catheterization and anticholinergic treatment is generally considered the gold standard of therapy. However, when this therapy fails surgical reconstruction become the only remaining option. This review will summarize the pathogenesis, risk factors, genetic contribution, diagnostic test, and management of SB. Lastly, the urologic outcomes and therapies are reviewed.

Are fetal gender and gestational age related to the size of cisterna magna?

OBJECTIVES

The purpose of this article was to explore whether the gestational age(GA)and gender could affect the size of the cisterna magna (CM).

METHODS

This study that included pregnant women who were between 20 ∼ 39⁺⁶. The recorded included BPD, HC, anteroposterior diameter of CM and gender. The fetuses were divided into normal and isolated enlargement of the CM (IECM)group for statistical analysis.

RESULTS

Seven hundred ninety six fetuses with normal CM, 412 cases were boys and 384 cases were girls. 73 fetuses with IECM, 59 cases were boys and 14 cases were girls. The anteroposterior diameter of the CM increased with GA during 20-26⁺⁶weeks. After 27 weeks, the anteroposterior diameter of CM became stable. In the IECM group, the mean anteroposterior of male and female fetuses were 1.31 ± 0.18 cm and 1.24 ± 0.15 cm, respectively. The IECM fetus accounted for 8.4% of the total number of fetuses, male IECM accounted for 14.3% of normal male fetus, and female fetus was 3.6%, which showed that male fetus had a higher rate of IECM than female (χ2 = 21.6, p<.001).

CONCLUSIONS

There is a gender difference between normal fetuses and IECM fetuses. Based on our finding, it is reasonable to establish the normal value of CM according to the gender difference.

Prenatal Repair of Spina Bifida: A 2-Center Experience with Open Intrauterine Neurosurgery in Chile

OBJECTIVE

To report the experience with prenatal repair of open spina bifida (OSB) from 2 centers in Chile.

METHODS

Women with a second-trimester fetus with OSB were offered intrauterine neurosurgical repair following the protocol from the Management of Myelomeningocele Study (MOMS) trial. Pediatric follow-up with infants reaching 12 and 30 months of life was also reviewed.

RESULTS

Fifty-eight fetuses with OSB underwent intrauterine repair at an average (±SD) gestational age of 24.8 ± 0.9 weeks. There were 3 (5.1%) intrauterine deaths. The average gestational age at delivery of the remaining 55 cases was 33.3 ± 3.6 weeks, and the average birth weight was 2,172 ± 751 g. Delivery before 30 weeks occurred in 11 cases (20.0%). Two (3.6%) neonatal deaths (<28 days) occurred. At 12 months, a ventriculoperitoneal shunt or an endoscopic third ventriculostomy was required in 25% of the cases. At 30 months, 72.4% of the infants were able to walk.

DISCUSSION

Prenatal neurosurgical repair of OSB is a complex and challenging intervention. Major complications include perinatal death and severe prematurity. No major maternal complications occurred in our series. A reduction in the need for cerebrospinal fluid diversion and an improved ability to walk seem to be the greatest long-term advantages of this procedure.

Fetal profile in fetuses with open spina bifida

OBJECTIVE

To determine whether the frontomaxillary facial (FMF) angle and the prefrontal space ratio (PFSR) are helpful in screening for open spinal defects by ultrasound in the second and third trimesters of pregnancy.

METHODS

The FMF angle and the PFSR were measured in fetuses with spina bifida according to standardized protocols. The normal range of the PFSR was previously published by our group. To determine the normal values for the FMF angle in the second and third trimesters of pregnancy, we used the same stored images from the above-mentioned study.

RESULTS

71 affected and 279 normal fetuses were included in this study. Median gestational ages in the two groups were 21.1 weeks and 21.6 weeks, respectively. In fetuses with spina bifida, the FMF angle was significantly smaller than in the normal population (72.9° versus 79.6°). However, the measurement was below the fifth centile in only 22.5% of the affected fetuses. The PFSR was similar in both groups.

CONCLUSIONS

The FMF angle is smaller in second and third trimester fetuses with open spina bifida. However, the difference is not large enough to implement this marker in current screening programs.

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.

Ratio of fetal choroid plexus to head size: simple sonographic marker of open spina bifida at 11-13 weeks' gestation

OBJECTIVES

To measure the ratio of choroid plexus (CP) size to head size in normal fetuses and to compare it to that in fetuses with open spina bifida (OSB) and quantify the subjective sign of a 'dry brain'.

METHODS

This was a retrospective study of ultrasound images, obtained during first-trimester screening between 11 and 13 weeks of gestation, from 34 fetuses with OSB and 160 normal fetuses. From the hospital databases, we retrieved images of the fetal head in the transventricular axial plane. We measured the areas of both CPs and the head and calculated the ratio between them. We also measured the longest diameter of each CP and calculated their mean (CP length), and measured the occipitofrontal diameter (OFD) and calculated the ratio of CP length to OFD. Measurements from the OSB fetuses were plotted on crown-rump length (CRL) reference ranges constructed using data from the normal fetuses, and Z-scores were calculated.

RESULTS

In the normal fetuses, the CP area increased, while the ratios of CP area to head area and CP length to OFD decreased, with increasing CRL. In 30 of the 34 (88%) fetuses with OSB, both ratios were increased significantly and the CPs filled the entirety of the head, giving the impression of a dry brain. In these cases, the borders of the lateral ventricles could not be identified.

CONCLUSIONS

At 11-13 weeks, the majority of fetuses with OSB have reduced fluid in the lateral ventricles such that the CPs fill the head. The dry brain sign is easily visualized during routine first-trimester ultrasound examination while measuring the biparietal diameter, and can be quantified by comparing the size of the CPs to the head size. Until prospective data confirm the usefulness of this sign in screening for OSB, it should be considered as a hint to prompt the examiner to assess thoroughly the posterior fossa and spine. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Urological presentations of adult primary tethered cord syndrome

AIMS

To investigate the urological presentations of patients initially diagnosed with closed spinal dysraphism in adulthood: adult primary tethered cord syndrome (ApTCS).

METHODS

Patients with ApTCS who underwent subsequent untethering were studied. Urological presentations were evaluated grouped by symptom onset period of either after (group 1) or before (group 2) the completion of physical growth.

RESULTS

Of the 43 patients, median age at diagnosis and initial untethering was 35.5 (18.4-67.2) years. At diagnosis, 90.7% (39/43) had urological symptoms and 18.6% (8/43) initially consulted a urologist without noticeable neurological symptoms. Enuresis was observed in 16.3% (7/43) and common among patients without significant neurological symptoms (62.5%, 5/8). Urgency urinary incontinence and frequency prevailed in group 1. Stress urinary incontinence and straining to void prevailed in group 2. Among 26 patients with pre- and post-operative urodynamics, detrusor overactivity predominated in group 1 and acontractile detrusor predominated in group 2. Glomerular filtration rate ≥90 mL/min/1.73m² was noted in 86.0% (37/43) and 84.9% (73/86) of renal units were morphometrically intact. More patients in group 2 (93.3%) relied on assisted emptying than in group 1 (53.6%).

CONCLUSIONS

In ApTCS, enuresis was prevalent among patients without noticeable neurological symptoms. Over 80% in both groups had favorable renal function. Bladder conditions were different based on symptom onset period. Significantly more patients whose symptoms developed before completion of growth relied on assisted emptying. Proper discerning might be crucial in ApTCS which has a potential of misdiagnosis even in the modern developed era.

Bioengineering of Fetal Skin: Differentiation of Amniotic Fluid Stem Cells into Keratinocytes

PURPOSE

Open fetal spina bifida repair has become a novel clinical standard of care. In very large spina bifida lesions, the skin defect cannot be covered primarily, asking for alternative solutions. We hypothesize that amniotic fluid stem cells (AFSC) could be differentiated into keratinocytes that could then be used to bioengineer autologous skin usable for in utero back coverage.

METHODS

To obtain human AFSC, amniotic fluid samples obtained from fetal surgeries were subjected to immunoselection for c-kit. C-kit-positive samples and controls were cultured with the additives morphogenetic protein 4 and vitamin C to induce differentiation towards keratinocytes. This process was monitored by measuring the expression of K8 and K14 via immunohistochemical staining, flow cytometry, and polymerase chain reaction.

RESULTS

After immunoselection and expansion, most cells were positive for K8, but none for K14. After completion of the differentiation protocol, cell colonies with keratinocyte-like appearance could be observed, but cells remained positive for K8 and negative for K14, indicating failed differentiation into keratinocytes.

CONCLUSIONS

Culturing of keratinocyte-like cells from AFSC, harvested intraoperatively, was not feasible in this setting. The reasons for failure must be investigated and eliminated, as bioengineering of fetal skin for clinical use during fetal surgery for spina bifida remains an attractive goal.

First-trimester cystic posterior fossa: reference ranges, associated findings, and pregnancy outcomes

OBJECTIVE

To report reference ranges for fetal cerebral posterior fossa measurements and to describe the sonographic findings, karyotype results, and pregnancy outcomes in fetuses presenting with cystic posterior fossa (CPF) in the first trimester of pregnancy.

METHODS

Two groups of patients undergoing first-trimester sonographic screening at 11-13 weeks' gestation were studied. The first (control group) consisted of 253 consecutive fetuses with normal posterior fossa, in which the brainstem (BS), fourth ventricle, cisterna magna, and BS-occipital bone (BS-OB) diameter were prospectively measured and the BS/BS-OB diameter ratio was calculated. The second (study group) consisted of 14 fetuses in which a CPF was detected. Information on sonographic findings, prenatal karyotype results, and pregnancy outcomes was obtained by reviewing ultrasound reports and medical records. The results from the two groups were then compared.

RESULTS

In the control group, the size of all posterior fossa structures increased and the BS/BS-OB diameter ratio slightly decreased as the pregnancy progressed. In the study group, the BS diameter did not differ significantly from the measurements obtained in the control group. However, the BS-OB diameter and the fourth ventricle were significantly larger (p < .05 and p < .001, respectively) in the study group than in the control group. Additionally, the cisterna magna was not identified in 13 of the 14 fetuses (93%) in the study group, in comparison to zero out of the 253 fetuses in the control group (p < .001). Finally, the BS/BS-OB diameter ratio was significantly smaller in the study group when compared with the control group (p < .05). Regarding pregnancy outcomes, 12 of the 14 (86%) affected pregnancies underwent elective termination (n = 11) or ended in an early intrauterine demise (n = 1) due to the associated chromosomal abnormalities or structural defects. The two fetuses with isolated CPF had a normal second-trimester scan and resulted in the delivery of healthy newborn infants.

CONCLUSIONS

The detection of a CPF in the first trimester is associated with a high rate of chromosomal and structural defects. By using normative data, early sonographic screening and detection of mildly and moderately abnormal cases is possible. Fetuses with isolated CPF require further study with a detailed second-trimester scan. This is essential in order to differentiate cases with poor and good perinatal outcomes. Finally, our data also demonstrate that the main sonographic tool when screening for CPF in the first trimester is the assessment of the fourth ventricle, which is significantly larger in abnormal cases as the result of the wide communication between the fourth ventricle and the cisterna magna.

Spina bifida in pregnancy: A review of the evidence for preconception, antenatal, intrapartum and postpartum care

Women with spina bifida in pregnancy require complex multi-disciplinary management. Most women have uncomplicated pregnancies; however, complications are more frequent than in 'low risk' pregnancies. Careful antenatal planning and management of the complications can optimise outcome. There are currently no guidelines on the management of pregnant women with spina bifida, but there is a growing body of evidence from case reports and series examining the antenatal and postnatal course of these women. In this review, we examine the available literature and provide a framework on the prenatal counselling, antenatal, intrapartum and postnatal management of pregnant women with spina bifida.

Use of plastic wound retractor at hysterotomy site in prenatal repair of myelomeningocele: a new technique

Objective: To describe the use of a self-retaining thermoplastic polyurethane wound retractor for the management of hysterotomy during prenatal repair of myelomeningocele.Methods: The preliminary experience with 16 consecutive cases of open surgery for prenatal repair of myelomeningocele using a new technique is presented. Under general anesthesia, the gravid uterus was partially exteriorized through a low transverse abdominal incision and a high 3-4-cm midline vertical mini-hysterotomy was performed. After chorioamniotic membranes were opened with scissors, the internal ring of the retractor was placed into the amniotic cavity to compress the chorioamniotic membranes against the internal uterine wall and permit full retraction of the hysterotomy. Once the neurosurgical intervention was completed, the retractor was removed manually and uterine and abdominal incisions were closed using conventional techniques. Intra- and post-operative complications, as well as short-term pregnancy outcomes, were evaluated.Results: Intrauterine surgery was performed at a mean gestational age of 25.3 weeks and all except two of the interventions were completed within 3.0 h. When compared with the technique described in the Management of Myelomeningocele study (MOMS) trial, the use of the retractor was associated with a lower, although statistically nonsignificant, rate of chorioamniotic membrane separation (20/78 (26%) versus 2/16 (13%), respectively), preterm rupture of membranes (36/78 (46%) versus 4/16 (25%), respectively), and persistent oligohydramnios (16/78 (21%) versus 1/16 (6%), respectively) as well as higher gestational age at delivery (34.1 weeks ± 3.1 versus 36.0 weeks ± 1.93, respectively) and birthweight (2383 g ± 688 versus 2790 g ± 529, respectively). There were no intra- or post-operative complications associated with the use of the device. Only one (6%) of the hysterotomy scars was noted to be thin at the time of the cesarean delivery and no cases of dehiscence occurred.Conclusions: The use of a plastic wound retractor at the hysterotomy site provides a less traumatic approach than the conventional technique for the management of the uterine incision during open intrauterine surgery. Our experience with this technique was associated with short-term pregnancy outcomes that are similar and perhaps even superior to the technique reported in the MOMS trial. Because the device is inexpensive, easy to use, and widely available, its use during open intrauterine surgery should be considered. However, further clinical experience is required to reach a definitive conclusion regarding whether this technique should be incorporated into the protocol of prenatal repair of myelomeningocele.

Termination of pregnancy due to fetal central nervous system abnormalities performed after 24 weeks' gestation: survey of 57 fetuses from a single medical center

PURPOSE

To assess fetal central nervous system (CNS) abnormalities presenting as major findings leading to late termination of pregnancy (late TOP) performed ≥ 24 weeks' gestation.

METHOD

The study population included 2789 pregnant women that underwent late TOP in our institute between the years 1998 and 2015.

RESULTS

Fifty-seven cases (2.0%) underwent late TOP because of fetal CNS indications and are the subjects of the current study. Those cases were subdivided into four categories (1) no routine prenatal screening with an incidental finding discovered ≥ 24 weeks' gestation (25 patients, 43.8%); (2) developmental or acquired findings detected during late second and third trimester (22 patients, 38.6%); (3) apparently normal routine screening with abnormal findings that could have been detected earlier (six patients, 10.6%); (4) routine prenatal care raised suspicion of abnormalities, and the final diagnosis was established only following additional tests (four patients, 7.0%).

CONCLUSIONS

Combining the two categories of CNS abnormalities, i.e., pregnant women who did not undergo any fetal evaluation (group 1) and those that could have been detected earlier (group 3) consists 54% from our cohort in which late TOP could have been avoided. On contrary, 39% fetuses from our study population had CNS developmental findings which could be detected only at advanced stage of gestation.

A survey of health professionals' views on acceptable gestational age and termination of pregnancy for fetal anomaly

Termination of pregnancy for fetal anomaly is legal in the UK with no upper limit, if two doctors, in good faith, agree "there is a substantial risk that if the child were born it would suffer from such physical or mental abnormalities as to be seriously handicapped". This is Clause E of the Human Fertlisation and Embryology Act. The most commonly sighted Clause is C, which states "the pregnancy has not exceeded its twenty-fourth week and that the continuance of the pregnancy would involve risk, greater than if the pregnancy were terminated, of injury to the physical or mental health of the pregnant woman". This study aimed to investigate health professionals' views on gestational age and acceptable termination of pregnancy for fetal anomaly (TOPFA). We undertook a questionnaire survey of UK health professionals working in fetal medicine, obstetrics and gynaecology and neonatology. A study pack consisting of a self-completion questionnaire, an invitation letter, participant information sheet, and a stamped addressed return envelope, were sent to health professionals. We used four fetal anomalies as case study examples in the questionnaire: isolated cleft lip, hypoplastic left heart, spina bifida and trisomy 21. These anomalies were chosen as they differed in terms of the type of anomaly, the type of impairment, and the perceived severity. Forty-one study packs were returned. For anomalies deemed less serious, later gestational ages were an important consideration when deciding acceptable TOPFA. The prognosis of an anomaly was considered an important factor in deciding whether a TOPFA was acceptable alongside gestational age. Clause C of the current UK legislation, which allows a legal termination prior to 24 weeks gestational age if continuing with the pregnancy would impact the mental health of the mother, was deemed a reasonable option for termination when parents are requesting a TOPFA. For each case study example, health professionals responded that TOPFA at '25 weeks and over' was acceptable (cleft lip n = 1; hypoplastic left heart n = 19; spina bifida n = 13 and Trisomy 21 n = 10). Professionals also distinguished between their personal and professional views. These findings offer new insight into how gestational age considerations influence professionals' conceptualisation of acceptable TOPFA.

Non-visualization of choroid plexus of fourth ventricle as first-trimester predictor of posterior fossa anomalies and chromosomal defects

OBJECTIVE

To assess non-visualization of the choroid plexus of the fourth ventricle (CP-4V) as a simple, qualitative and reproducible first-trimester ultrasound feature of the posterior fossa for the prediction of central nervous system (CNS) anomalies and chromosomal defects.

METHODS

First-trimester three-dimensional ultrasound datasets of the fetal brain were obtained prospectively from 65 consecutive normal singletons and retrospectively from 27 fetuses identified as having an abnormal posterior fossa on first-trimester ultrasound examination, and randomly combined to form the final study group. The stored ultrasound volumes were analyzed offline by two accredited sonologists, who were not aware of the final diagnoses. The CP-4V was assessed by multiplanar navigation and classified as visible or non-visible in its normal position depending on whether or not the echogenic structure that separates the fourth ventricle from the cisterna magna was identified in both midsagittal and axial planes. Correlation with subsequent second-trimester ultrasound, fetal magnetic resonance imaging, or postmortem or postnatal findings was performed to determine the predictive value of the first-trimester findings.

RESULTS

Among the 92 ultrasound datasets analyzed, 73 (79%) were acquired transabdominally and 19 (21%) transvaginally. The CP-4V was classified as visible in 64 cases and non-visible in 28 cases, with agreement between the two observers in both sagittal and axial planes in all but one case. Twelve of the 28 (43%) fetuses with non-visible CP-4V were subsequently diagnosed as having a CNS malformation (open spina bifida (n = 6), Dandy-Walker malformation (n = 2), Blake's pouch cyst (n = 2), cephalocele (n = 1) and megacisterna magna (n = 1)). In addition, 20 of these 28 (71%) fetuses had aneuploidy (trisomy 18 (n = 10), triploidy (n = 5), trisomy 13 (n = 3), Turner syndrome (n = 1) or trisomy 21 (n = 1)). There was only one false-positive case, in which the CP-4V was classified as absent in a normal fetus.

CONCLUSIONS

Non-visualization of the CP-4V in the first trimester appears to be a strong marker of posterior fossa anomalies and chromosomal defects. Qualitative evaluation of this anatomic structure is simple, feasible and reproducible, and its routine assessment during the first-trimester scan may facilitate the early detection of CNS anomalies and associated fetal aneuploidy. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.