Surviving against the odds: exploring the clinical and radiological features of iniencephaly compatible with life. Illustrative case

BACKGROUND

Iniencephaly is a rare neural tube defect (NTD) characterized by deformities in the occiput and inion, along with rachischisis in the cervical and thoracic spine, resulting in the head appearing in retroflexion.

OBSERVATIONS

This report details the case of a female newborn who underwent surgery for an encephalocele. She survived up to 6 months, exhibiting good overall health, although she displayed physical abnormalities, including facial deformity, a short neck, and minor spasms in all limbs. Both cardiovascular and abdominal assessments remained stable, and imaging revealed defects in the occipital bone, a large cephalocele, and spinal dysraphism.

LESSONS

Although iniencephaly is generally incompatible with life, a few cases have been reported otherwise. Our patient, one of these notable exceptions, remains alive at 6 months old, possibly due to the lack of major vascular deformities. However, she does exhibit significant psychomotor retardation.

Ambulation after in-utero fetoscopic and open spina bifida repair: predictors for ambulation at 30 months

OBJECTIVE

Ambulatory outcomes from children who underwent a new minimally invasive fetal spina bifida surgery approach are included in this study for the first time. Identifying cases with better chances of independent ambulation from fetal life can have an important impact on patient counseling. The objectives of this study were: (1) To compare the ambulatory status of a cohort of children who had a prenatal spina bifida repair using two different methods (fetoscopic and open) with a cohort who underwent postnatal repair; and (2) to identify the best predictors for ambulation.

METHODS

Retrospective review of a cohort of children who had spina bifida repair from 2011-2023 using prenatal fetoscopic surgery (N=73), prenatal open-hysterotomy surgery (N=37) or postnatal repair (N=51) in a single tertiary hospital. Consecutive sample of cases who underwent a spina bifida repair in utero following MoMs trial criteria and cases who underwent postnatal repair, meeting same criteria, also followed up after birth at the same institution. Motor function (MF) assessment by ultrasound was recorded at initial evaluation (MF1), 6 postoperative weeks or equivalent (MF2) and prior to delivery (MF3). Clinical exams to assess MF at birth and at 12 months were recorded. First sacral myotome (S1) MF was classified as "intact MF". Ambulatory status data at each follow-up visit was collected. The proportion of cases who were able to walk independently were compared between fetoscopic and open prenatal surgeries and between prenatal (by fetoscopic or open surgery) and postnatal spina bifida repair. Logistic regression analyses were performed to identify predictors for independent ambulation.

RESULTS

At 30 months, the proportion of independent ambulators was higher in prenatally vs. postnatally repaired cases (51.8% vs.15.7%; p<0.01). No differences in ambulatory outcomes were seen in the comparison between fetoscopic (52%) vs. open (51.3%; p=0.95) prenatal repair. In the prenatal repair group, having an "intact MF" at 12 months [Odds ratio 7.71 (95%CI: 2.77-21.47), p<0.01] and at birth [4.38 (1.53-12.56), p<0.01], predicted significantly being an independent ambulator by 30 months; the anatomical level of lesion below L2 was also predictive for this outcome [3.68(1.33-9.88), p=0.01].

CONCLUSION

Ambulatory status by 30 months can be predicted by observing S1 MF postnatally. Results from this study have implications for parental counseling and planning for supportive therapies. This article is protected by copyright. All rights reserved.

Functional analysis of germline VANGL2 variants using rescue assays of vangl2 knockout zebrafish

Developmental studies have shown that the evolutionarily conserved Wnt Planar Cell Polarity (PCP) pathway is essential for the development of a diverse range of tissues and organs including the brain, spinal cord, heart and sensory organs, as well as establishment of the left-right body axis. Germline mutations in the highly conserved PCP gene VANGL2 in humans have only been associated with central nervous system malformations, and functional testing to understand variant impact has not been performed. Here we report three new families with missense variants in VANGL2 associated with heterotaxy and congenital heart disease p.(Arg169His), non-syndromic hearing loss p.(Glu465Ala) and congenital heart disease with brain defects p.(Arg135Trp). To test the in vivo impact of these and previously described variants, we have established clinically-relevant assays using mRNA rescue of the vangl2 mutant zebrafish. We show that all variants disrupt Vangl2 function, although to different extents and depending on the developmental process. We also begin to identify that different VANGL2 missense variants may be haploinsufficient and discuss evidence in support of pathogenicity. Together, this study demonstrates that zebrafish present a suitable pipeline to investigate variants of unknown significance and suggests new avenues for investigation of the different developmental contexts of VANGL2 function that are clinically meaningful.

Discordant exencephaly in case of a twin delivery: a case report

Introduction and importance

Neural tube defect occurs as a result of failure of spontaneous closure of the neural tube between the third and fourth weeks of foetal life. Exencephaly is a rare malformation of the neural tube characterized by a large amount of protruding brain tissue in the absence of the calvarium.

Case presentation

The authors report a 29-year-old female, non-compliant to iron, calcium and folic acid tablets due to nauseating and itchy sensation after intake for 2 weeks, was admitted in ward Obstetrics ward in view of twin pregnancy. After proper counselling, she was advised for caesarean section, which revealed gross malformation in the form of cleft lip, cleft palate and exposed brain tissue covered by thin layer of membrane with incompletely formed cranial vault and multiple-haematoma and ulcerations in the exposed brain tissue suggestive of Exencephaly. The deformed baby survived for 2 days after birth while the other baby was grossly healthy.

Clinical discussion

Exencephaly is said to be the embryological precursor anomaly of anencephaly. Exencephaly is a type of cranial malformation that characteristically involves a large disorganized mass of brain tissue. The flat bones of calvaria are absent and the brain mass is left uncovered. This condition is incompatible with life.

Conclusion

Each and every pregnant lady must be advised to undergo ultrasonography in every trimester, especially second trimester scan (anomaly scan) to diagnose any gross congenital malformations. Each pregnant lady is suggested to take the necessary vitamins (like folic acid) to avoid any Neural tube defects.

Revisiting MOMS criteria for prenatal repair of spina bifida: upper gestational-age limit should be raised and assessment of prenatal motor function rather than anatomical level improves prediction of postnatal function

OBJECTIVES

To determine if the lower-extremity neurological motor function level in fetuses with open spina bifida deteriorates within the 4-week interval between a first prenatal motor assessment at around 22 weeks of gestation and a second evaluation, prior to 'late' prenatal surgery, defined as surgery at 26-28 weeks and, in certain situations, up to 30 weeks, and to assess the association between prenatal presurgical motor-function level, anatomical level of the lesion and postnatal motor-function level.

METHODS

This was a two-center cohort study of 94 singleton fetuses with open spina bifida which underwent percutaneous repair using the skin-over-biocellulose for antenatal fetoscopic repair (SAFER) technique between December 2016 and January 2022. All women underwent two prenatal systematic ultrasound evaluations, approximately 4 weeks apart, with the second one being performed less than 1 week before surgery, and one postnatal evaluation via physical examination within 2 months of birth. Motor-function classification was from spinal level T12 to S1, according to key muscle function. Each leg was analyzed separately; in case of discrepancy between the two legs, the worst motor-function level was considered for analysis. Motor-function-level evaluations were compared with each other and with the anatomical level as observed on ultrasound. Independent predictors of a postnatal reduction in motor-function level were assessed using a logistic regression model.

RESULTS

Prenatal motor-function level was assessed at a median gestational age of 22.5 (interquartile range (IQR), 20.7-24.3) and 26.7 (IQR, 25.4-27.3) weeks, with a median interval of 4.0 (IQR, 2.4-6.0) weeks. The median gestational age at surgery was 27.0 (IQR, 25.9-27.6) weeks and the postnatal examination was at median age of 0.8 (IQR, 0.3-5.4) months. There was no significant difference in motor-function level between the two prenatal evaluations (P = 0.861). We therefore decided to use the second prenatal evaluation for comparison with postnatal motor function and anatomical level. Overall, prenatal and postnatal motor function evaluations were significantly different from the anatomical level (preoperative assessment, P = 0.0015; postnatal assessment, P = 0.0333). Comparing prenatal with postnatal motor-function level, we found that 87.2% of babies had similar or improved motor function compared with that prior to prenatal surgery. On logistic regression analysis, lower anatomical level of defect and greater difference between anatomical level and prenatal motor-function level were identified as independent predictors of postnatal motor function (odds ratio, 0.237 (95% CI, 0.095-0.588) (P = 0.002) and 3.44 (95% CI, 1.738-6.813) (P < 0.001), respectively).

CONCLUSIONS

During a 4-week interval between first ultrasound evaluation and late fetal surgical repair of open spina bifida, motor function does not change significantly, suggesting that late repair, ≥ 26 weeks, does not impact negatively on motor-function outcome. Compared with the anatomical level of the lesion, preoperative neurological motor-function assessment via ultrasound is more predictive of postnatal motor function, and should be included in preoperative counseling. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Differential responses to maternal diabetes in embryo and visceral yolk sac

Introduction: Maternal diabetes during pregnancy is well known to be associated with a higher risk for structural birth defects in the offspring. Recent searches for underlying mechanisms have largely focused on aberrant processes in the embryo itself, although prior research in rodent models implicated dysfunction also of the visceral yolk sac. The objective of our research was to investigate both tissues within the conceptus simultaneously. Methods: We conducted unbiased transcriptome profiling by RNA sequencing on pairs of individual yolk sacs and their cognate embryos, using the non-obese diabetic (NOD) mouse model. The analysis was performed at gestational day 8.5 on morphologically normal specimen to circumvent confounding by defective development. Results: Even with large sample numbers (n = 33 in each group), we observed considerable variability of gene expression, primarily driven by exposure to maternal diabetes, and secondarily by developmental stage of the embryo. Only a moderate number of genes changed expression in the yolk sac, while in the embryo, the exposure distinctly influenced the relationship of gene expression levels to developmental progression, revealing a possible role for altered cell cycle regulation in the response. Also affected in embryos under diabetic conditions were genes involved in cholesterol biosynthesis and NAD metabolism pathways. Discussion: Exposure to maternal diabetes during gastrulation changes transcriptomic profiles in embryos to a substantially greater effect than in the corresponding yolk sacs, indicating that despite yolk sac being of embryonic origin, different mechanisms control transcriptional activity in these tissues. The effects of maternal diabetes on expression of many genes that are correlated with developmental progression (i.e. somite stage) highlight the importance of considering developmental maturity in the interpretation of transcriptomic data. Our analyses identified cholesterol biosynthesis and NAD metabolism as novel pathways not previously implicated in diabetic pregnancies. Both NAD and cholesterol availability affect a wide variety of cellular signaling processes, and can be modulated by diet, implying that prevention of adverse outcomes from diabetic pregnancies may require broad interventions, particularly in the early stages of pregnancy.

A quality improvement initiative to improve folic acid supplementation counseling for adolescent females with epilepsy

OBJECTIVE

We designed a quality improvement (QI) project to improve rates of documented folic acid supplementation counseling for adolescent females with epilepsy, consistent with a quality measure from the American Academy of Neurology and American Epilepsy Society. Our SMART aim was to increase the percentage of visits at which folic acid counseling was addressed from our baseline rate of 23% to 50% by July 1, 2020.

METHODS

This initiative was conducted in female patients ≥12 years old with epilepsy who were prescribed daily antiseizure medication and were seen by the 13 providers in our Neurology QI Program. Using provider interviews, we undertook a root cause analysis of low counseling rates and identified the following main factors: insufficient time during clinic visit to counsel, lack of provider knowledge, and forgetting to counsel. Countermeasures were designed to address these main root causes and were implemented through iterative plan-do-study-act (PDSA) cycles. Interventions included provider education and features within the electronic health record, which were introduced sequentially, culminating in the creation of a best practice advisory (BPA). We performed biweekly chart reviews of visits for applicable patients to establish baseline performance rate and track progress over time. We used a statistical process control p-chart to analyze the outcome measure of documented counseling. As a balancing measure, clinicians were surveyed using the Technology Adoption Model survey to assess acceptance of the BPA.

RESULTS

From September 2019 to August 2022, the QI team improved rates of documented folic acid counseling from 23% to 73% through several PDSA cycles. This level of performance has been sustained over time. The most successful and sustainable intervention was the BPA. Provider acceptance of the BPA was overall positive.

SIGNIFICANCE

We successfully used QI methodology to improve and sustain our rates of documented folic acid supplementation counseling for adolescent females with epilepsy.

Anterolateral Thoracic Myelomeningocele With Split Cord Malformation

We present a case of a two-year-old male with a history of congenital scoliosis and anterolateral thoracic meningocele. He was able to walk and run, but his parents reported left leg weakness and a frequent cough. The patient had normal neurological examination findings. Magnetic resonance imaging (MRI) of the spine without contrast showed left convex upper thoracic congenital scoliosis and rightward anterolateral meningocele inferiorly to T3, with the spinal cord tethered at this location. Neurosurgical cord detethering and repair of the meningocele were performed simultaneously with scoliosis repair by orthopedics. During the dissection of the meningocele, the bulging neural tissue was found to be a split cord ending in a blind stump. The split cord was determined to be nonfunctional via Prass probe (Medtronic, Minneapolis, MN) stimulation and was subsequently dissected. Detethering of the spinal cord was followed by repair of the dural outpouching and dural closure. The patient was stable post-surgery, but long-term results remain to be seen.

First-time tethered cord release among adults with myelomeningocele: an analysis of people in the National Spina Bifida Patient Registry

OBJECTIVE

The authors analyzed the National Spina Bifida Patient Registry (NSBPR), a national registry that tracks the outcomes for people with various forms of spinal dysraphism, to determine the ongoing longitudinal risk for tethered cord release (TCR) among adults with myelomeningocele who had not previously undergone TCR during childhood. The authors also sought to identify the impact of lesion level, ambulation status, and prior treatments for hydrocephalus or Chiari malformations on TCR rates.

METHODS

Adults in the registry who had not previously undergone TCR during childhood were studied. This group was compared with the remaining adults in the registry. The frequency of first-time TCR and time to TCR (using Kaplan-Meier analysis) were determined independently for males and females. Cox proportional hazards analysis identified correlations between sex, best lesion level and ambulation status prior to TCR, and previous treatments for hydrocephalus and Chiari decompression.

RESULTS

Among 967 adults in the NSBPR (422 [43.6%] males and 545 [56.4%] females) who had not undergone TCR during childhood, the authors identified 47 people (4.9%) who underwent their first TCR during adulthood. This study cohort had significantly better mean functional motor levels and ambulation compared with the remaining adult cohort (both p < 0.001). The study group included 35 females (74.5%) and 12 males (25.5%); this sex distribution was significantly different in comparison with the remaining adult cohort (p = 0.016). The Kaplan-Meier curves for first TCR for females and males were significantly different (p = 0.01, log-rank test). TCR rates were correlated with sex (males had decreased risk; OR 0.31, 95% CI 0.16-0.62, p < 0.001), prior treatment for hydrocephalus (those who underwent prior treatment had decreased risk; OR 0.21, 95% CI 0.20-0.42, p < 0.001), and prior treatment for Chiari malformation (those who underwent prior treatment had greater risk; OR 3.84, 95% CI 1.50-9.88, p = 0.005).

CONCLUSIONS

Adults with myelomeningocele who escape childhood without undergoing TCR have an ongoing, albeit decreased, risk for spinal cord tethering requiring TCR. This risk is obviously not due to spinal column growth and therefore must reflect other factors such as dynamic changes in spinal cord health over time. Among people with MMC who underwent their first TCR as adults, females seemed to be overrepresented. Similar to the authors' prior childhood study, people who underwent previous Chiari decompression seemed to be overrepresented, whereas those who underwent previous treatment for hydrocephalus seem to be underrepresented. These novel findings deserve further study.

Neural Tube Defect in a Resource Limited Setting: Clinical Profile and Short Term Outcome

Background

There is a huge burden of neural tube defect (NTD) in Ethiopia, and surgical management is not readily available. We aimed to assess the clinical profile and hospital outcome of children with NTD that were operated in Hawassa University Comprehensive Specialized Hospital, Hawassa, Ethiopia.

Methods

A retrospective cross-sectional study on 250 children with NTD that were treated in a tertiary hospital from March 2016 to May 2020 was conducted to describe the clinical profile and treatment outcome at discharge. Logistic regression analysis was carried out to evaluate factors that determine mortality.

Results

Out of the 250 children, 50.4% were male. Myelomeningocele was the most common type of NTD (77.2%) followed by meningocele (10.4%). Only 3 mothers (1.2%) received periconceptional folic acid. Prenatal diagnosis of NTD was made in only 22 (8.8%) cases. 52.8% of the NTDs were ruptured at presentation and 50.8% had associated sepsis. At presentation, 42.4% were ≤72 hours of age and only 18 neonates (7.2%) were operated within 72 hours of admission. 54% had associated hydrocephalus, 31.6% had Chiari II malformation and 19.6% had club foot. Surgical site infection, post MMC repair hydrocephalus, and meningitis were seen in 8%, 14% and 16.8% of the participants, respectively. The mean duration of hospitalization was 24 ± 14.4 days. Twenty patients (8%) died before discharge from hospital. Prematurity [AOR: 26 (95% CI: 8.01, 86.04), P < 0.001] and the presence of meningitis [AOR: 3.8 (95% CI: 1.12,12.9), P = 0.03]were determinants of mortality.

Conclusion

NTDs are substantial health problem in this part of the country. Periconceptional folic acid supplementation is almost non-existent. Prenatal detection of NTDs is very low and management is delayed in the majority of cases. Myelomeningocele is the most common type of NTD. There is high in-hospital mortality, and prematurity and the presence of meningitis are its determinants.

Prenatal predictors of need for cerebrospinal fluid diversion in infants following prenatal repair of open spina bifida; systematic review and meta-analysis

OBJECTIVE

This study aimed to investigate prenatal predictors of the need for cerebrospinal fluid diversion in infants following prenatal repair of open spina bifida.

DATA SOURCES

A systematic search was performed to identify relevant studies published from inception until June 2022 in the English language using the databases PubMed, Scopus, and Web of Science.

STUDY ELIGIBILITY CRITERIA

We included retrospective and prospective cohort studies and randomized controlled trials reporting on prenatal repair of open spina bifida.

METHODS

The random-effects model was used to pool the mean differences or odds ratios and the corresponding 95% confidence intervals. Heterogeneity was assessed using the I2 value.

RESULTS

A total of 9 studies including 948 pregnancies undergoing prenatal repair of open spina bifida were included in the final analysis. Prenatal factors that were significantly associated with the need for postnatal cerebrospinal fluid diversion were gestational age at surgery ≥25 weeks (odds ratio, 4.2; 95% confidence interval, 1.8-9.9; I2=54%; P=.001), myeloschisis (odds ratio, 2.2; 95% confidence interval, 1.1-4.1; I2=0.0%; P=.02), preoperative lateral ventricle width ≥15 mm (odds ratio, 4.5; 95% confidence interval, 2.9-6.9; I2=0.0%; P<.0001), predelivery lateral ventricle width (mm) (mean difference, 8.3; 95% confidence interval, 6.4-10.2; I2=0.0%; P<.0001), and preoperative lesion level at T12-L2 (odds ratio, 2.5; 95% confidence interval, 1.03-6.3; I2=68%; P=.04). Factors that significantly reduced the need for postnatal shunt placement were gestational age at surgery <25 weeks (odds ratio, 0.3; 95% confidence interval, 0.15-0.6; I2=67%; P=.001) and preoperative lateral ventricle width <15 mm (odds ratio, 0.3; 95% confidence interval, 0.2-0.4; I2=0.0%; P<.0001).

CONCLUSION

This study demonstrated that among fetuses that underwent surgical repair of open spina bifida, having gestational age at surgery of ≥25 weeks, preoperative lateral ventricle width of ≥15 mm, myeloschisis lesion type, and preoperative lesion level above L3 was predictive of the need for cerebrospinal fluid diversion during the first year of life.

Gene-nutrient interactions that impact magnesium homeostasis increase risk for neural tube defects in mice exposed to dolutegravir

In 2018, data from a surveillance study in Botswana evaluating adverse birth outcomes raised concerns that women on antiretroviral therapy (ART) containing dolutegravir (DTG) may be at increased risk for neural tube defects (NTDs). The mechanism of action for DTG involves chelation of Mg²⁺ ions in the active site of the viral integrase. Plasma Mg²⁺ homeostasis is maintained primarily through dietary intake and reabsorption in the kidneys. Inadequate dietary Mg²⁺ intake over several months results in slow depletion of plasma Mg²⁺ and chronic latent hypomagnesemia, a condition prevalent in women of reproductive age worldwide. Mg²⁺ is critical for normal embryonic development and neural tube closure. We hypothesized that DTG therapy might slowly deplete plasma Mg²⁺ and reduce the amount available to the embryo, and that mice with pre-existing hypomagnesemia due to genetic variation and/or dietary Mg²⁺ insufficiency at the time of conception and initiation of DTG treatment would be at increased risk for NTDs. We used two different approaches to test our hypothesis: 1) we selected mouse strains that had inherently different basal plasma Mg²⁺ levels and 2) placed mice on diets with different concentrations of Mg²⁺. Plasma and urine Mg²⁺ were determined prior to timed mating. Pregnant mice were treated daily with vehicle or DTG beginning on the day of conception and embryos examined for NTDs on gestational day 9.5. Plasma DTG was measured for pharmacokinetic analysis. Our results demonstrate that hypomagnesemia prior to conception, due to genetic variation and/or insufficient dietary Mg²⁺ intake, increases the risk for NTDs in mice exposed to DTG. We also analyzed whole-exome sequencing data from inbred mouse strains and identified 9 predicted deleterious missense variants in Fam111a that were unique to the LM/Bc strain. Human FAM111A variants are associated with hypomagnesemia and renal Mg²⁺ wasting. The LM/Bc strain exhibits this same phenotype and was the strain most susceptible to DTG-NTDs. Our results suggest that monitoring plasma Mg²⁺ levels in patients on ART regimens that include DTG, identifying other risk factors that impact Mg²⁺ homeostasis, and correcting deficiencies in this micronutrient might provide an effective strategy for mitigating NTD risk.

Presurgery motor level assessment for prediction of motor level at birth in fetuses undergoing prenatal repair of open spina bifida: time to abandon anatomical level in counseling

OBJECTIVES

First, to investigate the correlation between prenatal presurgery anatomical and motor levels of the lesion with motor level at birth in cases undergoing prenatal repair of open spina bifida and, second, to identify factors leading to a loss of two or more motor levels between the presurgery and postnatal assessments.

METHODS

This was an observational study of singleton pregnancies undergoing prenatal repair of open spina bifida, conducted between March 2011 and May 2022. All fetuses underwent an ultrasound assessment at 20-24 weeks of gestation to determine the motor and anatomical levels of the lesion before surgery. The anatomical level of the lesion was defined as the highest open posterior vertebral arch. The motor level was determined by systematic observation of the lower limb movements and was defined as the most distal active muscle present. Prenatal repair was performed at 23-26 weeks. At birth, motor level was assessed by a rehabilitation specialist by physical examination. Cases of intrauterine death or termination of pregnancy and those delivered at other sites were excluded from the neonatal assessment. The agreement between presurgery motor level and motor level at birth, and between presurgery anatomical level and motor level at birth, was assessed using the weighted kappa index (wκ). Logistic regression analysis was used to assess factors leading to a loss of two or more motor levels between the presurgery and postnatal assessments.

RESULTS

Presurgery motor and anatomical levels were assessed in 61 fetuses at a median gestational age of 22.7 (interquartile range (IQR), 21.6-24.4) weeks. Prenatal repair was performed at a median gestational age of 24.6 (IQR, 23.7-25.7) weeks. Motor level at birth was assessed in 52 neonates after exclusion of nine fetuses due to loss to follow-up or fetal loss. There was moderate agreement between presurgery motor level and motor level at birth (wκ = 0.42; 95% CI, 0.21-0.63), with a median difference of 0 (IQR, -2 to 9) levels. Factors leading to a loss of two or more motor levels between the presurgery ultrasound assessment and postnatal examination were higher presurgery anatomical level (odds ratio (OR), 0.59 (95% CI, 0.35-0.98); P = 0.04) and larger difference between the anatomical and motor levels before surgery (OR, 1.85 (95% CI, 1.12-3.06); P = 0.017). None of the other ultrasound, surgery-related or neonatal variables assessed was associated significantly with a loss of two or more motor levels. There was slight agreement between the presurgery anatomical level of the lesion and motor level at birth (wκ = 0.07; 95% CI, -0.02 to 0.15).

CONCLUSIONS

There is moderate agreement between fetal motor level of the lesion before prenatal repair of open spina bifida and motor level at birth, as opposed to only slight agreement between presurgery anatomical level and motor level at birth. A loss of two or more motor levels between the presurgery and postnatal assessments is associated with a higher presurgery anatomical level and with a larger difference between the presurgery anatomical and motor levels. Consequently, motor level, rather than the anatomical level, should be used for prenatal counseling. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Implication of chromosomal microarray analysis prior to in-utero repair of fetal open neural tube defect

OBJECTIVE

In-utero repair of open neural tube defects (ONTD) is an accepted treatment option with demonstrated superior outcome for eligible patients. While current guidelines recommend genetic testing by chromosomal microarray analysis (CMA) when a major congenital anomaly is detected prenatally, the requirement for an in-utero repair, based on the Management of Myelomeningocele Study (MOMS) criteria, is a normal karyotype. In this study, we aimed to evaluate if CMA should be recommended as a prerequisite for in-utero ONTD repair.

METHODS

This was a retrospective cohort study of pregnancies complicated by ONTD that underwent laparotomy-assisted fetoscopic repair or open-hysterotomy fetal surgery at a single tertiary center between September 2011 and July 2021. All patients met the MOMS eligibility criteria and had a normal karyotype. In a subset of the pregnancies (n = 77), CMA testing was also conducted. We reviewed the CMA results and divided the cohort into two groups according to whether clinically reportable copy-number variants (CNV) were detected (reportable-CNV group) or not (normal-CMA group). Surgical characteristics, complications, and maternal and early neonatal outcomes were compared between the two groups. The primary outcomes were fetal or neonatal death, hydrocephalus, motor function at 12 months of age and walking status at 30 months of age. Standard parametric and non-parametric statistical tests were employed as appropriate.

RESULTS

During the study period, 146 fetuses with ONTD were eligible for and underwent in-utero repair. CMA results were available for 77 (52.7%) patients. Of those, 65 (84%) had a normal CMA and 12 (16%) had a reportable CNV, two of which were classified as pathogenic. The first case with a pathogenic CNV was diagnosed with a 749-kb central 22q11.21 deletion spanning low-copy-repeat regions B-D of chromosome 22; the second case was diagnosed with a 1.3-Mb interstitial deletion at 1q21.1q21.2. Maternal demographics, clinical characteristics, operative data and postoperative complications were similar between those with normal CMA results and those with reportable CNVs. There were no significant differences in gestational age at delivery or any obstetric and early neonatal outcome between the study groups. Motor function at birth and at 12 months of age, and walking status at 30 months of age, were similar between the two groups.

CONCLUSIONS

Standard diagnostic testing with CMA should be offered when an ONTD is detected prenatally, as this approach has implications for counseling regarding prognosis and recurrence risk. Our results indicate that the presence of a clinically reportable CNV should not a priori affect eligibility for in-utero repair, as overall pregnancy outcome is similar in these cases to that of cases with normal CMA. Nevertheless, significant CMA results will require a case-by-case multidisciplinary discussion to evaluate eligibility. To generalize the conclusion of this single-center series, a larger, multicenter long-term study should be considered. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Neural tube defects among new borns: a cross-sectional study

Background

Neural tube defects are a major public health issue that contributes significantly to morbidity and mortality, particularly in low-income countries such as Ethiopia. In Ethiopia, particularly in the study setting, there is a paucity of data on the prevalence, magnitude, and associated factors of neural tube defects. As a result, the purpose of this study was to evaluate neural tube defects and associated factors in JUMC.

Methods

This study was an institution-based cross-sectional study conducted from June to September 2021. Data was collected using a structured questionnaire adapted from previous literature. Data were analyzed using SPSS version 26 software. Logistic regression analysis was performed to assess the association between dependent and independent variables. Independent variables with a p-value < 0.05 were taken as statistically significant with neural tube defects.

Results

The prevalence of NTDs in this study was 3.6%. Preterm newborns with GA < 34 AOR 2.9(1.2-9.7), newborns with birth weight b/n 1,000-1,499 AOR 5.2(1.1-9.4), born with weight b/n 1,500-2,499 AOR 2.1(1.3-8.7), exposure to smoke AOR 2.1(1.2-8.8), radiation AOR 6.8(1.3-14.5), at least one history of abortion AOR 10.1(7.2-21.0) and mothers with AED intake AOR 5.7(2.3-18.4) were found to be associated significantly.

Conclusion

The results indicated a significant frequency of neural tube abnormalities in newborns. The use of AEDs, abortion, and radiation have all been linked to those NTD cases. Pregnant women are advised to learn more about the need of beginning prenatal care as soon as possible because the aforementioned issues will be addressed during this treatment.

Neural tube defects: Prevalence, mortality, and maternal characteristics in two departmental hospitals in the northwestern region of Nicaragua, 2006-2018

BACKGROUND

Congenital anomalies are the fifth most common cause of neonatal mortality in Nicaragua, and neural tube defects (NTDs) are the most common of all cases of lethality associated with a birth defect. Prevalence and mortality estimates are needed to propose effective intervention strategies that prevent NTDs over time.

METHODS

A cross-sectional study was carried out in northwestern Nicaragua from January 2006 to December 2018. All cases of NTDs (anencephaly, spina bifida, and encephalocele) were registered in hospital surveillance systems, and the medical histories of the mothers and newborns were reviewed. Prevalence was calculated by considering the number of live births and stillbirths older than 20 weeks of gestation with NTDs, divided by the total number of live births and stillbirths in each study year. Neonatal mortality rate (NMR) for NTD, and case fatality for spina bifida was calculated.

RESULTS

Two hundred fifty cases of NTDs were identified from 178,498 deliveries (177,316 live births and 1,182 stillbirths). The prevalence of NTDs during this time period was 14.01 (95% CI: 12.27-15.74) per 10,000 births. The prevalence of spina bifida (n = 140), anencephaly (n = 97), and encephalocele (n = 13) was 7.84, (95% CI: 6.54-9.14), 5.43 (95% CI: 4.30-6.45), and 0.73 (95% CI: 0.33-1.12) per 10,000 births, respectively. Mothers with fetus or newborns affected with NTDs did not use folic acid prior to conception, and 11% experienced periods of hyperthermia during the first trimester of pregnancy. NMR for NTDs was 0.55 per 1.000 livebirths. Case fatality for all NTDs and for spina bifida were 55% and 18%, respectively.

CONCLUSION

The prevalence and mortality of NTDs in the northwestern region of Nicaragua present peaks and troughs during the study period. Spina bifida was the most frequent type of NTD. We believe that these findings could be of use by health policy makers to strengthen the primary prevention of NTDs in the region through the monitoring of the food fortification policy and folic acid supplementation to women of childbearing age. Additional etiologic studies of NTDs should be considered to identify additional prevention measures.

Challenging, giant occipital encephalocele in a pediatric saipanese male

Key Clinical Message

Giant occipital encephalocele is a rare form of congenital anomaly that involves protrusion of brain tissue (greater in size than the patient's cranial cavity) from a defect in the skull. This case reports illustrates repair of a giant encephalocele and emphasizes important methods to reduce risk for blood loss and other complications.

Abstract

A rare form of congenital anomaly, giant occipital encephalocele involves protrusion of brain tissue from a defect in the skull (in this case from the occiput). While encephalocele itself is a fairly rare entity, those qualifying as "giant"-defined by size of the deformity exceeding that of the skull itself - require very technically challenging surgery.

Identification of Neurocan and Phosphacan as Early Biomarkers for Open Neural Tube Defects

Open neural tube defects (NTDs) such as myelomeningocele (MMC) are debilitating and the most common congenital defects of the central nervous system. Despite their apparent clinical importance, the existing early prenatal diagnostic options for these defects remain limited. Using a well-accepted retinoic-acid-induced model of MMC established in fetal rats, we discovered that neurocan and phosphacan, the secreted chondroitin sulfate proteoglycans of the developing nervous system, are released into the amniotic fluid (AF) of fetal rats displaying spinal cord defects. In contrast to normal controls, elevated AF levels of neurocan and phosphacan were detected in MMC fetuses early in gestation and continued to increase during MMC progression, reaching the highest level in near-term fetuses. The molecular forms of neurocan and phosphacan identified in the AF of MMC fetuses and those found in MMC spinal cords were qualitatively similar. In summary, this is the first report demonstrating the presence of neurocan and phosphacan in the AF of MMC fetuses. The identification of elevated levels of neurocan and phosphacan in the AF of MMC fetuses provides two prospective biomarkers with the potential for early prenatal diagnosis of open NTDs.

Local conceptions of the role of folate in neural tube defects in Zambia

OBJECTIVE

In sub-Saharan Africa, neural tube defects (NTDs) are the second most common birth defect, occurring eight times more frequently than in the US. The objective of this study was to assess baseline Zambian caregiver understanding of folate and NTDs and the effectiveness of an NTD prevention educational program.

METHODS

This prospective survey-based study included Zambian caregivers of children born with NTDs who completed pre- and post-educational program surveys between January 2020 and January 2021. The verbal survey was administered in English or local Zambian dialects. The 1-hour educational program administered by local Zambian research nurses sought to facilitate understanding of the direct relationship between prenatal folate supplementation and NTDs.

RESULTS

Sixty-one eligible caregivers with a median age of 20 (IQR 24-29) years completed the survey. Participants were predominantly from regions outside of Lusaka Province (68%, 41/60) rather than the capital city, Lusaka (32%, 19/60). Most had received prenatal care (91%, 57/61), and 80% (47/59) reported folate use in pregnancy. Of the mothers who took folate during pregnancy, 24% (11/45) reported use within the first 4 weeks after conception, while 76% (34/45) started thereafter. Myelomeningocele was the most common NTD (74%, 32/43), followed by meningocele (14%, 6/43). Prior to the educational program, 52% (29/56) of caregivers reported that NTDs were caused by a vitamin deficiency, which improved to 98% (55/56) after the program (p < 0.001). Furthermore, only 54% (33/61) of caregivers believed that folate should be taken before conception on the baseline survey evaluation, which improved to 95% (58/61, p < 0.001) after the program. All survey participants (58/58) found the educational session helpful.

CONCLUSIONS

This study found that a high proportion of Zambian caregivers had received prenatal care and even had taken folate during pregnancy, but none had taken it prior to pregnancy. An educational program effectively improved understanding about the role and timing of perinatal folate administration in NTD prevention. This result also emphasizes the need for folate fortification and folate education for not only mothers but also primary care providers.

Aberrant lipid accumulation in the mouse visceral yolk sac resulting from maternal diabetes and obesity

Maternal diabetes and obesity in pregnancy are well-known risk factors for structural birth defects, including neural tube defects and congenital heart defects. Progeny from affected pregnancies are also predisposed to developing cardiometabolic disease in later life. Based upon in vitro embryo cultures of rat embryos, it was postulated that nutrient uptake by the yolk sac is deficient in diabetic pregnancies. In contrast, using two independent mouse models of maternal diabetes, and a high-fat diet-feeding model of maternal obesity, we observed excessive lipid accumulation at 8.5 days in the yolk sac. The numbers as well as sizes of intracellular lipid droplets were increased in yolk sacs of embryos from diabetic and obese pregnancies. Maternal metabolic disease did not affect expression of lipid transporter proteins, including ApoA1, ApoB and SR-B1, consistent with our earlier report that expression of glucose and fatty acid transporter genes was also unchanged in diabetic pregnancy-derived yolk sacs. Colocalization of lipid droplets with lysosomes was significantly reduced in the yolk sacs from diabetic and obese pregnancies compared to yolk sacs from normal pregnancies. We therefore conclude that processing of lipids is defective in pregnancies affected by maternal metabolic disease, which may lead to reduced availability of lipids to the developing embryo. The possible implications of insufficient supply of lipids -and potentially of other nutrients-to the embryos experiencing adverse pregnancy conditions are discussed.

Cellular senescence and developmental defects

Cellular senescence is a distinct state that is frequently induced in response to ageing and stress. Yet studies have also uncovered beneficial functions in development, repair and regeneration. Current opinion therefore suggests that timely and controlled induction of senescence can be beneficial, while misregulation of the senescence program, either through mis-timed activation, or chronic accumulation of senescent cells, contributes to many disease states and the ageing process. Whether atypical activation of senescence plays a role in the pathogenesis of developmental defects has been relatively underexplored. Here, we discuss three recent studies that implicate ectopic senescence in neurodevelopmental defects, with possible causative roles for senescence in these birth defects. In addition, we highlight how the examination of senescence in other birth defects is warranted, and speculate that aberrantly activated senescence may play a much broader role in developmental defects than currently appreciated.

Intrauterine closure of myelomeningocele defects with primary linear repair versus bipedicle fasciocutaneous flaps: a post-MOMS cohort study with long-term follow-up

OBJECTIVE

The objective of this study was to determine the effects of in utero bipedicle flaps on maternal-fetal morbidity/mortality, the need for CSF diversion, and long-term functional outcomes.

METHODS

Eighty-six patients who underwent fetal myelomeningocele repair from 2011 to 2021 at a single institution were reviewed. Primary outcomes included intrauterine fetal demise, postnatal death, postnatal myelomeningocele repair dehiscence, and CSF diversion by final follow-up.

RESULTS

The cohorts were no different with regard to race, ethnicity, maternal age at fetal surgery, body mass index, gravidity, parity, gestational age at fetal surgery, estimated fetal weight at fetal surgery, or fetal lesion level. Of the 86 patients, 64 underwent primary linear repair and 22 underwent bipedicle flap repair. There were no significant differences in rates of intrauterine fetal demise, postnatal mortality, midline repair site dehiscence, or the need for CSF diversion by final follow-up. Operative times were longer (32.5 vs 18.7 minutes, p < 0.001) and gestational age at delivery was lower (232 vs 241 days, p = 0.01) in the bipedicle flap cohort, but long-term functional outcomes were not different.

CONCLUSIONS

Analysis of the total cohort affirms the long-term benefits of fetal myelomeningocele repair. In utero bipedicle flaps are safe and can be used for high-tension lesions without increasing perioperative risks to the mother or fetus. In utero flaps preserve the long-term benefits seen with primary linear repair and may expand inclusion criteria for fetal repair, providing life-changing care for more patients.

Neural Tube Defects from Antenatal Diagnosis to Discharge - a Tertiary Academic Centre Experience

Background

Bleeding Worldwide, approximately 300,000 infants are born annually with neural tube defects (NTDs), which carry a high risk of morbidity and mortality.

Objective

The aim of the study was to describe the experience with NTD patients born at a tertiary academic center.

Methods

A retrospective record review of all neonates with NTD admitted to the neonatal intensive care unit over six years.

Results

Out of the 39 patients identified, 32 (82.1%) were diagnosed antenatally. Most NTD cases were of the myelomeningocele 26 (66.7%) type. The most common site of the myelomeningocele was lumbar, and the thoracolumbar site had the worst prognosis.

Conclusion

Early detection of the disease allows better planning of delivery and treatment decisions. Nevertheless, understanding the magnitude of the problem necessitates adopting public health prevention strategies for better outcomes.

Folate-deficiency induced acyl-CoA synthetase short-chain family member 2 increases lysine crotonylome involved in neural tube defects

Maternal folate deficiency increases the risk of neural tube defects (NTDs), but the mechanism remains unclear. Here, we established a mouse model of NTDs via low folate diets combined with MTX-induced conditions. We found that a significant increase in butyrate acid was observed in mouse NTDs brains. In addition, aberrant key crotonyl-CoA-producing enzymes acyl-CoA synthetase short-chain family member 2 (ACSS2) levels and lysine crotonylation (Kcr) were elevated high in corresponding low folate content maternal serum samples from mouse NTD model. Next, proteomic analysis revealed that folate deficiency led to global proteomic modulation, especially in key crotonyl-CoA-producing enzymes, and dramatic ultrastructural changes in mouse embryonic stem cells (mESCs). Furthermore, we determined that folate deficiency induced ACSS2 and Kcr in mESCs. Surprisingly, folic acid supplementation restored level of ACSS2 and Kcr. We also investigated overall protein post-translational Kcr under folate deficiency, revealing the key regulation of Kcr in glycolysis/gluconeogenesis, and the citric acid cycle. Our findings suggest folate deficiency leads to the occurrence of NTDs by altering ACSS2. Protein crotonylation may be the molecular basis for NTDs remodeling by folate deficiency.

Neuroprotection is improved by watertightness of fetal spina bifida repair in the sheep model

OBJECTIVES

A contributing factor to unsuccessful prenatal spina bifida aperta (SBA) repair via an open approach may be incomplete neurosurgical repair causing persistent in-utero leakage of cerebrospinal fluid (CSF) and exposure of the fetal spinal cord to amniotic fluid. We aimed to investigate the neurostructural and neurofunctional efficacy of watertight prenatal SBA repair in a validated SBA fetal lamb model.

METHODS

A well-powered superiority study was conducted in the validated SBA fetal lamb model (n = 7 per group). The outcomes of lambs which underwent watertight or non-watertight multilayer repair through an open approach were compared to those of unrepaired SBA lambs (historical controls) at delivery (term = 145 days). At ∼75 days, fetal lambs underwent standardized induction of lumbar SBA. At ∼100 days, they were assigned to an either watertight or non-watertight layered repair group based on an intraoperative watertightness test using subcutaneous fluorescein injection. At 1-2 days postnatally, as primary outcome, we assessed reversal of hindbrain herniation using magnetic resonance imaging (MRI). Secondary proxies of neuroprotection were: absence of CSF leakage at the repair site; hindlimb motor function based on joint-movement score, locomotor grade and Motor Evoked Potential (MEP); four-score neuroprotection scale, encompassing live birth, complete hindbrain herniation reversal, absence of CSF leakage and joint-movement score ≥ 9/15; and brain and spinal cord histology and immunohistochemistry. As the watertightness test cannot be used clinically due to its invasiveness, we developed a potential surrogate intraoperative three-score skin-repair-quality scale based on visual assessment of the quality of the skin repair (suture inter-run distance ≤ 3 mm, absence of tear and absence of ischemia), with high quality defined by a score ≥ 2/3 and low quality by a score < 2/3, and assessed its relationship with improved outcome.

RESULTS

Compared with unrepaired lambs, lambs with watertight repair achieved a high level of neuroprotection (neuroprotection score of 4/4 in 5/7 vs 0/7 lambs) as evidenced by: a significant 100% (vs 14%) reversal of hindbrain herniation on MRI; low CSF leakage (14% vs 100%); better hindlimb motor function, with higher joint-movement score, locomotor grade and MEP area under the curve and peak-to-peak amplitude; higher neuronal density in the hippocampus and corpus callosum; and higher reactive astrogliosis at the SBA lesion epicenter. Conversely, lambs with non-watertight SBA repair did not achieve the same level of neuroprotection (score of 4/4 in 1/7 lambs) compared with unrepaired lambs, with: a non-significant 86% (vs 14%) reversal of hindbrain herniation; high CSF leakage (43% vs 100%); no improvement in motor function; low brain neuron count in both the hippocampus and corpus callosum; and small spinal astroglial cell area at the epicenter. Both watertight layered repair and high (≥ 2/3) intraoperative skin-repair-quality score were associated with improved outcome, but the watertightness test and skin-repair-quality scale could not be used interchangeably due to result discrepancies.

CONCLUSIONS

Watertight layered fetal SBA repair is neuroprotective since it improves brain and spinal-cord structure and function in the fetal lamb model. This translational research has important clinical implications. A neurosurgical technique that achieves watertightness should be adopted in all fetal centers to improve neuroprotection. Future clinical studies could assess whether a high skin-repair-quality score (≥ 2/3) correlates with neuroprotection. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

The First Case of Fetus in Fetu in Nicaragua: The Management Experience of the Pediatric Neurosurgery Team

Fetus in fetu (FIF) is a rare congenital anomaly of asymmetric monozygotic twins, where the parasitic twin develops abnormally inside the body of the host twin. In most cases, it is incorporated into the sibling's abdomen, which frequently presents as a retroperitoneal mass. Currently, at least 200 cases have been reported worldwide, being this the first case in Nicaragua. We describe a case of a male newborn, born via cesarean section, with a history of multiple congenital malformations observed via ultrasound examination. At birth, a mass is observed on its dorsum that impresses a skull, but without the presence of bones, with three limbs, two upper and one lower, with an outline located transversely on the pelvic girdle and the presence of two male genitalia with agenesis of the testicles and an accessory kidney. A preoperative diagnosis of FIF and spinal dysraphism was made by computed tomography (CT) and magnetic resonance imaging (MRI). They shared a spinal cord and had the presence of an open spinal defect type meningocele with aberrant roots. After the diagnosis and discussion, the multidisciplinary team proceeded to surgery to perform the separation of the twin (FIF). The subsequent anatomopathological examination revealed that the fetus was anencephalic and had reliable FIF characteristics. The resection was performed followed by the closure of the 430 mL meningocele and complete separation of the spine and the parasitic twin. We present the first case of fetus in fetu in Nicaragua.

Red blood cell folate level and associated factors of folate insufficiency among pregnant women attending antenatal care during their first trimester of pregnancy in Addis Ababa, Ethiopia

Objective:

Folate is an essential vitamin for de novo DNA synthesis and cell proliferation. Folate insufficiency at the time of conception and during the first trimester of pregnancy is associated with unintended pregnancy and birth outcomes, particularly neural tube defects. Hence, this study aimed to assess folate status and associated factors of folate insufficiency among pregnant women attending antenatal care during their first trimester of pregnancy in Addis Ababa, Ethiopia.

Materials and methods:

A cross-sectional study was conducted from 8 August 2017 to 3 January 2018 in Addis Ababa. In this study, 160 participants were enrolled via the convenience sampling method. Red blood cell folate was measured by the electrochemiluminescence binding assay method. Data were entered into Epi-Data version 3.1 and analyzed by SPSS version 22.0. Descriptive statistics were used to describe demographic characteristics and to determine the magnitude of folate deficiency. Logistic regression was used to identify the risk factors for folate deficiency. A p-value of less than 0.05 was considered statistically significant.

Results:

In this study, 44/160 (27%) participants had red blood cell folate level <400 ng/mL, insufficient to prevent neural tube defect. Multivariate regression showed that regular vegetable consumption was an independent determinant factor for red blood cell folate level (adjusted odds ratio: 0.41, confidence interval: 0.18–0.93).

Conclusion:

This study shows that a large magnitude of the first-trimester pregnant women had red blood cell folate concentrations below levels that are maximally protective against neural tube defects. Folic acid supplementation and supplemental nutrition containing green leafy vegetables should be promoted during the periconceptional period. In addition, the policymakers should set rules for mandatory folic acid fortification.

Pathogenesis of neural tube defects: The regulation and disruption of cellular processes underlying neural tube closure

Neural tube closure (NTC) is crucial for proper development of the brain and spinal cord and requires precise morphogenesis from a sheet of cells to an intact three-dimensional structure. NTC is dependent on successful regulation of hundreds of genes, a myriad of signaling pathways, concentration gradients, and is influenced by epigenetic and environmental cues. Failure of NTC is termed a neural tube defect (NTD) and is a leading class of congenital defects in the United States and worldwide. Though NTDs are all defined as incomplete closure of the neural tube, the pathogenesis of an NTD determines the type, severity, positioning, and accompanying phenotypes. In this review, we survey pathogenesis of NTDs relating to disruption of cellular processes arising from genetic mutations, altered epigenetic regulation, and environmental influences by micronutrients and maternal condition. This article is categorized under: Congenital Diseases > Genetics/Genomics/Epigenetics Neurological Diseases > Genetics/Genomics/Epigenetics Neurological Diseases > Stem Cells and Development.

Guideline No. 427: Folic Acid and Multivitamin Supplementation for Prevention of Folic Acid-Sensitive Congenital Anomalies

OBJECTIVE

To provide updated guidance on pre-conception folic acid and multivitamin supplementation for primary and secondary (recurrence) prevention of neural tube defects and other folate-sensitive congenital anomalies.

TARGET POPULATION

Women aged 12-45 years who could become pregnant should be aware of the risk of serious birth defects without adequate pre-conception and first-trimester folic acid supplementation.

OPTIONS

Optimizing folic acid supplementation is complex and depends on factors including dosage; type of supplement; bioavailability of folate from food, timing of initiating supplementation; and metabolic and genetic factors. For all women who could become pregnant, a low daily dosage of folic acid is recommended before conception and throughout pregnancy and breastfeeding. High-dosage folic acid supplementation is recommended only for women who can become pregnant and have had a previous pregnancy affected by a neural tube defect or other folate-sensitive congenital anomaly. Directed personalized approaches could be considered and adopted for women who can become pregnant and have complex risks (genetic, medical, or surgical risk factors), using new knowledge of co-factor metabolism and synergy, as well as red blood cell or serum folate testing. Such approaches would require changes to current provincial health care maternal serum folate screening/testing.

OUTCOMES

New approaches to oral folic acid supplementation, including triage tools, need to be considered to optimize the benefits of decreasing risk of neural tube defects and folate-sensitive congenital anomalies.

BENEFITS, HARMS, AND COSTS

Oral folic acid supplementation, or dietary folate intake combined with a multivitamin/micronutrient supplement, is associated with lower rates of neural tube defects, other folate-sensitive birth defects, and obstetrical complications. The costs are those attributable to daily vitamin supplementation and a healthy, folate-rich diet.

EVIDENCE

A literature search was designed and carried in PubMed and the Cochrane Library databases from 1990 to 2021 using following MeSH terms and keywords (and variants): folic acid supplementation; folate food fortification; primary neural tube defect prevention; prevention of recurrence of neural tube defects; folate-sensitive birth defects; folate supplementation benefit; folate supplementation risk; folate pregnant woman physiology; pregnant woman RBC folate level; pregnant woman serum folate levels; folate and epilepsy; folate and obesity. This guideline was based upon expert guidelines or opinions, systematic reviews, randomized controlled clinical trials, and observational case-control studies and case series retrieved, published in English from 1990 to 2021.

VALIDATION METHODS

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and weak recommendations).

INTENDED AUDIENCE

Maternity health care providers (physicians, midwives, nurses) and other providers of pregnancy-related wellness and health counselling.

SUMMARY STATEMENTS

RECOMMENDATIONS.

Prevalence of supratentorial anomalies assessed by magnetic resonance imaging in fetuses with open spina bifida

OBJECTIVES

To determine the prevalence of brain anomalies at the time of preoperative magnetic resonance imaging (MRI) assessment in fetuses eligible for prenatal open spina bifida (OSB) repair, and to explore the relationship between brain abnormalities and features of the spinal defect.

METHODS

This was a retrospective cross-sectional study, conducted in three fetal medicine centers, of fetuses eligible for OSB fetal surgery repair between January 2009 and December 2019. MRI images obtained as part of the presurgical assessment were re-evaluated by two independent observers, blinded to perinatal results, to assess: (1) the type and area of the defect and its anatomical level; (2) the presence of any structural central nervous system (CNS) anomaly and abnormal ventricular wall; and (3) fetal head and brain biometry. Binary regression analyses were performed and data were adjusted for type of defect, upper level of the lesion (ULL), gestational age (GA) at MRI and fetal medicine center. Multiple logistic regression analysis was performed in order to identify lesion characteristics and brain anomalies associated with a higher risk of presence of abnormal corpus callosum (CC) and/or heterotopia.

RESULTS

Of 115 fetuses included, 91 had myelomeningocele and 24 had myeloschisis. Anatomical level of the lesion was thoracic in seven fetuses, L1-L2 in 13, L3-L5 in 68 and sacral in 27. Median GA at MRI was 24.7 (interquartile range, 23.0-25.7) weeks. Overall, 52.7% of cases had at least one additional brain anomaly. Specifically, abnormal CC was observed in 50.4% of cases and abnormality of the ventricular wall in 19.1%, of which 4.3% had nodular heterotopia. Factors associated independently with higher risk of abnormal CC and/or heterotopia were non-sacral ULL (odds ratio (OR), 0.51 (95% CI, 0.26-0.97); P = 0.043), larger ventricular width (per mm) (OR, 1.23 (95% CI, 1.07-1.43); P = 0.005) and presence of abnormal cavum septi pellucidi (OR, 3.76 (95% CI, 1.13-12.48); P = 0.031).

CONCLUSIONS

Half of the fetuses assessed for OSB repair had an abnormal CC and/or an abnormal ventricular wall prior to prenatal repair. The likelihood of brain abnormalities was increased in cases with a non-sacral lesion and wider lateral ventricles. These findings highlight the importance of a detailed preoperative CNS evaluation of fetuses with OSB. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Correlation of fetal ventricular size and need for postnatal cerebrospinal fluid diversion surgery in open spina bifida

OBJECTIVES

Open spina bifida is a common cause of hydrocephalus in the postnatal period. In-utero closure of the fetal spinal defect decreases the need for postnatal cerebrospinal fluid (CSF) diversion surgery. Good prenatal predictors of the need for postnatal CSF diversion surgery are currently lacking. In this study, we aimed to assess the association of fetal ventriculomegaly and its progression over the course of pregnancy with the rate of postnatal hydrocephalus requiring intervention.

METHODS

In this retrospective study, fetuses with a prenatal diagnosis of open spina bifida were assessed longitudinally. Ventricular diameter, as well as other potential predictors of the need for postnatal CSF diversion surgery, were compared between fetuses undergoing prenatal closure and those undergoing postnatal repair.

RESULTS

The diameter of the lateral ventricle increased significantly throughout gestation in both groups, but there was no difference in maximum ventricular diameter at first or last assessment between fetuses undergoing prenatal closure and those undergoing postnatal repair. There was no significant difference in the rate of progression of ventriculomegaly between the two groups, with a mean progression rate of 0.83 ± 0.5 mm/week in the prenatal-repair group and 0.6 ± 0.6 mm/week in the postnatal-repair group (P = 0.098). Fetal repair of open spina bifida was associated with a lower rate of postnatal CSF diversion surgery (P < 0.001). In all subjects, regardless of whether they had prenatal or postnatal surgery, the severity of ventriculomegaly at first and last assessments was associated independently with the need for postnatal CSF diversion surgery (P = 0.005 and P = 0.001, respectively), with a greater need for surgery in fetuses with larger ventricular size, even after controlling for gestational age at assessment.

CONCLUSIONS

In fetuses with open spina bifida, fetal ventricular size increases regardless of whether spina bifida closure is performed prenatally or postnatally, but the need for CSF diversion surgery is significantly lower in those undergoing prenatal repair. Ventriculomegaly is associated independently with the need for postnatal CSF diversion in fetuses with open spina bifida, irrespective of timing of closure. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Cerebral Abnormalities in Spina Bifida: A Neuropathological Study

INTRODUCTION

Spina bifida (SB) is the most common neural tube defect in humans. Here, we analyzed systematically the neuropathological findings of the brain in SB cases.

METHODS

79 cases with SB aperta (SBA) and 6 cases with SB occulta (SBO) autopsied at the Charité Neuropathology from 1974 to 2000 were re-evaluated retrospectively. For this, case files and spinal cord as well as brain sections were studied.

RESULTS

While no brain malformations were detected in SBO cases, 95% of SBA cases had brain malformations. Main brain anomalies identified were hydrocephalus (71%), Chiari II malformation (36%), heterotopia (34%), other cerebellar anomalies (36%), gyrification defects (33%), and ependymal denudation (29%). Hydrocephalus was observed as early as gestational week 17 and was highly associated to Chiari II and ependymal denudation. In 55% SBA was accompanied by further anomalies not primarily affecting the CNS.

CONCLUSION

We confirm using neuropathologic methods brain malformations in most SBA but none in SBO cases. In addition to our previous radiologic study, we now demonstrate the high prevalence of cerebellar malformations and cerebral heterotopias in SBA. The early detection of hydrocephalus and Chiari II malformation in fetuses raises the question whether these arise parallel rather than in strict temporal sequence.

Embryonic Hypotaurine Levels Contribute to Strain-Dependent Susceptibility in Mouse Models of Valproate-Induced Neural Tube Defects

Valproic acid (VPA, valproate, Depakote) is a commonly used anti-seizure medication (ASM) in the treatment of epilepsy and a variety of other neurological disorders. While VPA and other ASMs are efficacious for management of seizures, they also increase the risk for adverse pregnancy outcomes, including neural tube defects (NTDs). Thus, the utility of these drugs during pregnancy and in women of childbearing potential presents a continuing public health challenge. Elucidating the underlying genetic or metabolic risk factors for VPA-affected pregnancies may lead to development of non-teratogenic ASMs, novel prevention strategies, or more targeted methods for managing epileptic pregnancies. To address this challenge, we performed unbiased, whole embryo metabolomic screening of E8.5 mouse embryos from two inbred strains with differential susceptibility to VPA-induced NTDs. We identified metabolites of differential abundance between the two strains, both in response to VPA exposure and in the vehicle controls. Notable enriched pathways included lipid metabolism, carnitine metabolism, and several amino acid pathways, especially cysteine and methionine metabolism. There also was increased abundance of ω-oxidation products of VPA in the more NTD-sensitive strain, suggesting differential metabolism of the drug. Finally, we found significantly reduced levels of hypotaurine in the susceptible strain regardless of VPA status. Based on this information, we hypothesized that maternal supplementation with L-carnitine (400 mg/kg), coenzyme A (200 mg/kg), or hypotaurine (350 mg/kg) would reduce VPA-induced NTDs in the sensitive strain and found that administration of hypotaurine prior to VPA exposure significantly reduced the occurrence of NTDs by close to one-third compared to controls. L-carnitine and coenzyme A reduced resorption rates but did not significantly reduce NTD risk in the sensitive strain. These results suggest that genetic variants or environmental exposures influencing embryonic hypotaurine status may be factors in determining risk for adverse pregnancy outcomes when managing the health care needs of pregnant women exposed to VPA or other ASMs.

Valproic acid promotes SOD2 acetylation: A potential mechanism of valproic acid-induced oxidative stress in developing systems

Valproic acid (VPA) is an antiepileptic, bipolar and migraine medication, which is associated with embryonic dysmorphology, more specifically neural tube defects (NTDs), if taken while pregnant. One mechanism by which VPA may cause NTDs is through oxidative stress that cause disruption of cell signaling. However, mechanisms of VPA-induced oxidative stress are not fully understood. Since VPA is a deacetylase inhibitor, we propose that VPA promotes mitochondrial superoxide dismutase-2 (SOD2) acetylation, decreasing SOD2 activity and increasing oxidant levels. Using the pluripotent embryonal carcinoma cell line, P19, VPA effects were evaluated in undifferentiated and neurodifferentiated cells. VPA treatments increased oxidant levels, oxidized the glutathione (GSH)/glutathione disulfide (GSSG) redox couple, and decreased total SOD and SOD2 activity in undifferentiated P19 cells but not in differentiated P19 cells. VPA caused a specific increase in mitochondrial oxidants in undifferentiated P19 cells, VPA did not alter respirometry measurements. Immunoblot analyses demonstrated that VPA increased acetylation of SOD2 at lysine⁶⁸ (AcK68 SOD2) in undifferentiated P19 cells but not in differentiated P19 cells. Pretreatments with the Nrf2 inducer, dithiol-3-thione (D3T), in undifferentiated P19 cells prevented increased oxidant levels, GSH/GSSG redox oxidation and restored total SOD and SOD2 activity, correlating with a decrease in AcK68 SOD2 levels. In embryos, VPA decreased total SOD and SOD2 activity and increased levels of AcK68 SOD2, and D3T pretreatments prevented VPA effects, increasing total SOD and SOD2 activity and lowering levels of AcK68 SOD2. These data demonstrate a potential, contributing oxidizing mechanism by which VPA incites teratogenesis in developing systems. Moreover, these data also suggest that Nrf2 interventions may serve as a means to protect developmental signaling and inhibit VPA-induced malformations.

Experience of 300 cases of prenatal fetoscopic open spina bifida repair: report of the International Fetoscopic Neural Tube Defect Repair Consortium

BACKGROUND

The multicenter randomized controlled trial Management of Myelomeningocele Study demonstrated that prenatal repair of open spina bifida by hysterotomy, compared with postnatal repair, decreases the need for ventriculoperitoneal shunting and increases the chances of independent ambulation. However, the hysterotomy approach is associated with risks that are inherent to the uterine incision. Fetal surgeons from around the world embarked on fetoscopic open spina bifida repair aiming to reduce maternal and fetal/neonatal risks while preserving the neurologic benefits of in utero surgery to the child.

OBJECTIVE

This study aimed to report the main obstetrical, perinatal, and neurosurgical outcomes in the first 12 months of life of children undergoing prenatal fetoscopic repair of open spina bifida included in an international registry and to compare these with the results reported in the Management of Myelomeningocele Study and in a subsequent large cohort of patients who received an open fetal surgery repair.

STUDY DESIGN

All known centers performing fetoscopic spina bifida repair were contacted and invited to participate in a Fetoscopic Myelomeningocele Repair Consortium and enroll their patients in a registry. Patient data entered into this fetoscopic registry were analyzed for this report. Fisher exact test was performed for comparison of categorical variables in the registry with both the Management of Myelomeningocele Study and a post-Management of Myelomeningocele Study cohort. Binary logistic regression analyses were used to assess the registry data for predictors of preterm birth at <30 weeks' gestation, preterm premature rupture of membranes, and need for postnatal cerebrospinal fluid diversion in the fetoscopic registry.

RESULTS

There were 300 patients in the fetoscopic registry, 78 in the Management of Myelomeningocele Study, and 100 in the post-Management of Myelomeningocele Study cohort. The 3 data sets showed similar anatomic levels of the spinal lesion, mean gestational age at delivery, distribution of motor function compared with upper anatomic level of the lesion in the neonates, and perinatal death. In the Management of Myelomeningocele Study (26.16±1.6 weeks) and post-Management of Myelomeningocele Study cohort (23.3 [20.2-25.6] weeks), compared with the fetoscopic registry group (23.6±1.4 weeks), the gestational age at surgery was lower (comparing fetoscopic repair group with the Management of Myelomeningocele Study; P<.01). After open fetal surgery, all patients were delivered by cesarean delivery, whereas in the fetoscopic registry approximately one-third were delivered vaginally (P<.01). At cesarean delivery, areas of dehiscence or thinning in the scar were observed in 34% of cases in the Management of Myelomeningocele Study, in 49% in the post-Management of Myelomeningocele Study cohort, and in 0% in the fetoscopic registry (P<.01 for both comparisons). At 12 months of age, there was no significant difference in the number of patients requiring treatment for hydrocephalus between those in the fetoscopic registry and the Management of Myelomeningocele Study.

CONCLUSION

Prenatal and postnatal outcomes up to 12 months of age after prenatal fetoscopic and open fetal surgery repair of open spina bifida are similar. Fetoscopic repair allows for having a vaginal delivery and eliminates the risk of uterine scar dehiscence, therefore protecting subsequent pregnancies of unnecessary maternal and fetal risks.

Study of C677T Methylene Tetrahydrofolate Reductase Gene Polymorphism as a Risk Factor for Neural Tube Defects

Introduction

Various genetic and environmental factors contribute to the development of neural tube defects (NTDs) which are a group of neurulation defects resulting from failure of closure of embryonic neural tube. Among genetic factors is polymorphism in methylene tetrahydrofolate reductase (MTHFR) gene, giving rise to a gene variant or mutant. However, in most studies directed at finding an association between MTHFR variants and NTD, there is no clear evidence of a cause-and-effect relationship.

Materials and Methods

Forty diagnosed cases of NTDs and forty healthy individuals were investigated in a case-control study for presence of C677T MTHFR gene polymorphism. Serum folate and Vitamin B12 levels were estimated and MTHFR gene polymorphism was detected by polymerase chain reaction-restriction fragment length polymorphism.

Results

It was found that 32 cases were homozygous with CC genotype and eight were heterozygous with CT genotype, whereas 35 controls had CC genotype and five had CT genotype. TT genotype was absent in both the groups. There was no statistically significant difference between both the groups. No evidence of association between MTHFR C677T polymorphism and NTDs was found.

Conclusion

Although there was no evidence of association between MTHFR C677T polymorphism and NTDs, our study does not rule out the impact of MTHFR gene mutation on folate metabolism. The reason for absence of TT genotype and no association could be a small sample size. Larger, comprehensive, and well-designed multicentric but feasible studies involving proper subjects and appropriate and adequate controls from several hospitals may provide more meaningful data.

Craniorachischisis with Exencephaly

Neural tube defects can be as mild as spina bifida, to as severe as anencephaly, with only a fraction of these cases presenting as both craniorachischisis and exencephaly. Case report: The G3, P1011 mother was 25-years old, who at an estimated fetal gestational age of 17 weeks had a fetal diagnosis of anencephaly based on a sonogram, resulting in elective pregnancy termination. The female fetus had an open neural tube defect, consisting of craniorachischisis and exencephaly. No abnormalities were noted in any other organs. Conclusion: Although mostly associated with anencephaly, craniorachischisis can also be associated with exencephaly in early pregnancy.

Predicted Effects and Cost-Effectiveness of Wheat Flour Fortification for Reducing Micronutrient Deficiencies, Maternal Anemia, and Neural Tube Defects in Yaoundé and Douala, Cameroon

BACKGROUND

Policy makers aiming to reduce micronutrient deficiencies (MNDs) and their health effects must choose among alternative definitions of impact when evaluating cost-effectiveness.

OBJECTIVE

Estimate the cost-effectiveness of a mandatory wheat flour fortification program for reducing cases of MNDs (iron, zinc, folate, vitamin B12), anemia and neural tube defects (NTDs) averted, and disability-adjusted life years (DALYs) averted in urban Cameroon.

METHODS

A 13-year predictive model was developed, including a 3-year start-up period and 10 years of program activity. Costs were estimated using historical program budgets. Effects were calculated based on observed changes in prevalence of MND and anemia 1 year postfortification and predicted reductions in NTDs based on NTD burden and wheat flour intake. Total DALYs averted were estimated for anemia and NTDs.

RESULTS

The program cost ∼$2.4 million over 13 years and averted an estimated ∼95 000 cases of maternal anemia and ∼83 500 cases of iron deficiency among children after 1 year. Cost/case-year averted for MNDs ranged from $0.50 for low plasma folate to $3.30 for iron deficiency and was $2.20 for maternal anemia. The program was predicted to avert 1600 cases of NTDs over 10 years at ∼$1500 per case averted. Estimated cost/DALY averted was $50 for NTDs and $115 for anemia.

CONCLUSIONS

In Cameroon, cost-effectiveness of wheat flour fortification varied by the measure of impact employed, but was classified as "very cost-effective" for all outcomes using World Health Organization criteria. Policy makers and their advisors must determine how best to use information on program costs and benefits to inform their decisions.

Longitudinal evaluation of motor function in patients who underwent prenatal or postnatal neural tube defect repair

OBJECTIVE

To compare the evolution of motor function from mid-gestation to 12 months of age between prenatally and postnatally repaired cases of open neural tube defect (ONTD).

METHODS

This was a retrospective cohort study of all fetuses that underwent prenatal (fetoscopic or open hysterotomy) or postnatal ONTD repair at a single institution between November 2011 and December 2018. The anatomical level of the lesion was defined as the upper bony spinal defect at initial magnetic resonance imaging assessment. Prenatal motor function of the lower extremities was evaluated by ultrasound according to the metameric level of the neurological lesion, based on the methodology of Carreras et al. Fetal motor function was assessed at referral, at 6 weeks after surgery in prenatally repaired cases or 6 weeks after referral in postnatally repaired cases (6-week follow-up) and at the last scan before delivery. In addition, motor function was assessed by a detailed neurological examination at birth and 12 months of age. First sacral (S1) neurological level of the lesion was considered as intact motor function. For statistical comparisons, we attributed numerical scores to each neurological level and motor function was expressed as median (range) neurological level. Motor function (as numerical score) and the proportion of cases with intact motor function and with motor function two or more levels better than expected based on the anatomical level of the lesion were compared between the prenatal- and postnatal-repair groups. Fetal motor function was compared to the anatomical level of the lesion at referral and a better motor function was defined when it was two or more levels better than the anatomical level of the lesion. To assess the evolution of motor function, we compared motor function at referral with that at each follow-up assessment using paired t-tests.

RESULTS

We included 127 patients with ONTD, of whom 93 underwent prenatal (51 fetoscopic and 42 open hysterotomy) and 34 postnatal repair. At the time of referral, cases in the prenatal- and postnatal-repair groups presented with a similar anatomical level of lesion (L3 (T9-S1) vs L3 (T7-S1); P = 0.52), similar motor function (S1 (L1-S1) vs S1 (L1-S1); P = 0.52) and a similar proportion of cases with intact motor function (81% vs 79%; P = 0.88) and with motor function two or more levels better than expected based on the anatomical level of the lesion (62% vs 74%; P = 0.24). When compared with prenatally repaired cases, postnatally repaired cases showed worse motor function at birth (S1 (L1-S1) vs L4 (L1-S1); P < 0.01) and at 12 months of age (S1 (L1-S1) vs L4 (L1-S1); P < 0.01). In the prenatal-repair group, motor function remained stable from the time of referral to 12 months of age (P = 0.26). Furthermore, the proportion of patients with intact motor function at referral (81% (75/93)) was similar to that at the 6-week follow-up (74% (64/87)), at the last scan before birth (74% (42/57)), at birth (68% (63/93)) and at 12 months of age (67% (39/58)) in the prenatal-repair group. In the postnatal-repair group, worse motor function, starting from the third trimester to 12 months of age, was observed. The proportion of patients with intact motor function at referral (79% (27/34)) was similar to that at 6-week follow-up (80% (12/15); P = 0.92), but was lower at the last assessment before birth (25% (2/8); P < 0.01), at birth (24% (8/34); P < 0.01) and at 12 months of age (28% (7/25); P < 0.01). Similar findings were noted when assessing the evolution of the proportion of cases with motor function two or more levels better than expected based on the anatomical level of the lesion in each group.

CONCLUSIONS

Infants with ONTD that underwent postnatal repair had worse motor function at birth and at 12 months of age than at mid-gestation and when compared with infants that underwent prenatal ONTD repair. Prenatal motor function assessment by ultrasound is an adequate tool to identify those infants who should have a good clinical motor function after delivery. Information obtained by fetal motor function assessment can have an important role for patient counseling and case selection for surgery. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Arnold-Chiari Malformation: Core Concepts

Arnold-Chiari malformation (ACM), a defect that involves downward displacement of the hindbrain and herniation of the cerebellar vermis, tonsils, pons, medulla, and fourth ventricle through the foramen magnum, is the most complex of the 4 types of Chiari malformations. Unique to the other types of Chiari malformations, approximately 95 percent of infants with ACM also present with an associated myelomeningocele (MMC), the most severe form of spina bifida. Among affected infants, those with symptomatic comorbidities incur a significantly higher morbidity and mortality risk. Prompt identification and diagnosis of ACM, as well as evidence-based postnatal and postsurgical nursing and medical care, is critical. Early surgical intervention can repair an existing MMC and restore proper cerebrospinal fluid circulation, which can dramatically improve patient outcomes and quality of life, and reduce disease and health care burden.

Economic analysis of prenatal fetoscopic vs open-hysterotomy repair of open neural tube defect

OBJECTIVE

Fetal repair of an open neural tube defect (ONTD) by open hysterotomy has been shown to reduce the need for ventriculoperitoneal shunting and improve motor outcomes for infants, but increases the risk of Cesarean section and prematurity. Fetoscopic repair is an alternative approach that may confer similar neurological benefits but allows for vaginal delivery and reduces the incidence of hysterotomy-related complications. We sought to compare the costs of care from fetal surgery until neonatal discharge, as well as the clinical outcomes, associated with each surgical approach.

METHODS

This was a retrospective cohort study of patients who underwent prenatal ONTD repair, using either the open-hysterotomy or the fetoscopic approach, at a single institution between 2012 and 2018. Clinical outcomes were collected by chart review. A cost-consequence analysis was conducted from the hospital perspective, and included all inpatient and ambulatory hospital and physician costs incurred for the care of mothers and their infants, from the time of maternal admission for fetal ONTD repair up to postnatal maternal and infant discharge. Costs were estimated using cost-to-charge ratios for hospital billing and the Medicare physician fee schedule for physician billing.

RESULTS

Seventy-eight patients were included in the analysis, of whom 47 underwent fetoscopic repair and 31 underwent open-hysterotomy repair. In the fetoscopic-repair group, compared with the open-repair group, fewer women underwent Cesarean section (53% vs 100%; P < 0.001) and the median gestational age at birth was significantly higher (38.1 weeks (interquartile range (IQR), 35.2-39.1 weeks) vs 35.7 weeks (IQR, 33.9-37.0 weeks); P < 0.001). No case of uterine dehiscence was observed in the fetoscopic-repair group, compared with an incidence of 16% in the open-repair group. After adjusting for baseline characteristics, there was no significant difference in the total cost of care between the fetoscopic-repair and the open-repair groups (median, $76 978 (IQR, $60 312-$115 386) vs $65 103 (IQR, $57 758-$108 103); P = 0.458).

CONCLUSIONS

Fetoscopic repair of ONTD, when compared with the open-hysterotomy approach, reduces the incidence of Cesarean section and preterm delivery with no significant difference in total costs of care from surgery to infant discharge. This novel approach may represent a cost-effective alternative to improve maternal and neonatal outcomes for this high-risk population. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Risk of neural tube defects according to maternal body mass index: a systematic review and meta-analysis

INTRODUCTION

The aim of our systematic review and meta-analysis was to evaluate the risk of neural tube defects (NTDs) according to the pre-pregnancy body mass index.

MATERIALS AND METHODS

Electronic databases were searched (MEDLINE, EMBASE, Web of Sciences, Scopus, ClinicalTrial.gov, OVID, and Cochrane Library). Selection criteria included prospective and retrospective cohort studies reporting the prevalence of fetal NTDs in obese, overweight, and underweight pregnant women. Odds ratios (ORs) comparing risk among these subsets of pregnancies with normal weight mothers were determined with 95% confidence intervals (CI). The evaluated outcome was the association between maternal underweight, overweight, and obesity and the risk of NTDs.

RESULTS

We included ten studies published between 2000 and 2017, including underweight, overweight, and obese pregnant women with fetal NTD (cases) and pregnant women with recommended BMI with fetal NTD (controls). Compared with normal BMI women, obese mothers were at significantly higher risk of fetal NTDs (0.53 vs. 0.33%; OR 1.62 95% CI 1.32-1.99, p < .0001), while no difference for the risk of NTDs was found when comparing overweight (0.34 vs. 0.32%; OR 1.09 95% CI 0.92-1.3, p = .3) and underweight (0.65 vs. 0.24%; OR 1.34 95% CI 0.73-2.47, p = .34) with normal weight pregnant women.

DISCUSSION

Obese pregnant women are at significantly higher risk NTDs, while no significant difference has been found in overweight and underweight pregnant women. Key message Obese pregnant women are at significantly higher risk of NTDs, such as spina bifida compared with normal weight women. No difference was found when comparing overweight and underweight with normal weight women.

Expanding the phenotype, genotype and biochemical knowledge of ALG3-CDG

Congenital disorders of glycosylation (CDGs) are a continuously expanding group of monogenic disorders of glycoprotein and glycolipid biosynthesis that cause multisystem diseases. Individuals with ALG3-CDG frequently exhibit severe neurological involvement (epilepsy, microcephaly, and hypotonia), ocular anomalies, dysmorphic features, skeletal anomalies, and feeding difficulties. We present 10 unreported individuals diagnosed with ALG3-CDG based on molecular and biochemical testing with 11 novel variants in ALG3, bringing the total to 40 reported individuals. In addition to the typical multisystem disease seen in ALG3-CDG, we expand the symptomatology of ALG3-CDG to now include endocrine abnormalities, neural tube defects, mild aortic root dilatation, immunodeficiency, and renal anomalies. N-glycan analyses of these individuals showed combined deficiencies of hybrid glycans and glycan extension beyond Man₅ GlcNAc₂ consistent with their truncated lipid-linked precursor oligosaccharides. This spectrum of N-glycan changes is unique to ALG3-CDG. These expanded features of ALG3-CDG facilitate diagnosis and suggest that optimal management should include baseline endocrine, renal, cardiac, and immunological evaluation at the time of diagnosis and with ongoing monitoring.

Polystyrene nanoplastics exposure caused defective neural tube morphogenesis through caveolae-mediated endocytosis and faulty apoptosis

Growing evidence demonstrated that bioaccumulation of polystyrene nanoplastics (PS-NPs) in various organisms including human beings caused destructive effects on health. Nanoplastics may adversely affect fetal development potentially since they can pass through the placental barrier. However, very little has been known about the embryonic toxicity of polystyrene nanoplastics, especially in embryonic neurulation, the early developmental stage of the fetus, as well as the corresponding mechanisms. In this study, we first observed that 60- or 900-nm PS-NPs (especially 60-nm PS-NPs) could cross mouse placentas and affect developing mice fetuses. To avoid the indirect adverse effects derived from the restricted placenta, we employed early chick embryos as a developmental model to evaluate direct adverse effects of PS-NPs on embryo/fetal development, revealing suppressive effects on embryo development and an increased frequency of congenital abnormalities (especially in the nervous system), including neural tube defects. Thus, we focused on the potential negative effects of PS-NPs on neurulation, the earliest stage of nervous system development. Using caveolin-1 immunofluorescent staining of SH-SY5Y cells exposed to PS-NPs-GFP, we demonstrated that PS-NPs were internalized by SH-SY5Y cells via caveolae-mediated endocytosis. Transmission electron microscopy; LC3B immunofluorescent staining; and Atg7, Atg5, p62 and LC3B western blot results revealed that autophagy was activated in SH-SY5Y cells exposed to PS-NPs. However, PS-NPs were not degraded by the autophagic-lysosomal system given the lack of LAMP1 changes and minimal PS-NPs-GFP and LAMP1 colocalization. Furthermore, the cytoplasmic accumulation of PS-NPs caused faulty apoptotic cell death in SH-SY5Y cells and the developing neural tube as revealed by c-caspase3 immunofluorescent staining. Thus, defective neural tube morphogenesis, as demonstrated by neural tube defects, occurred during embryogenesis in the context of PS-NP exposure.

The VANGL1 P384R variant cause both neural tube defect and Klippel-Feil syndrome

Background

Neural tube defect (NTD) is a common birth defect causing much death in the world. Variants in VANGL1 lead to NTD and caudal regression syndrome. NTD displays a complex phenotype encompassing both genetic and environmental factors.

Methods

The fetus was diagnosed by prenatal ultrasound examination. Postnatal CT and autopsy were performed. Genetic testing was conducted in the family and Sanger sequencing was validated. Multiple prediction soft‐wares were used to predict the pathogenicity of the variant.

Results

The VANGL1 gene variant c.1151C>G (P384R) was detected in a fetus diagnosed with tethered spinal cord and sacrococcygeal lipoma. The VANGL1 variant c.1151C>G (P384R) was reported in a Klippel‐Feil syndrome patient. The VANGL1 variant was validated in the trio‐family but the mother showed no abnormalities.

Conclusion

Overall, this study presents fetal NTD caused by the same VANGL1 variant found in a Klippel‐Feil syndrome patient with complete clinical information of prenatal ultrasound, postnatal CT, and genetic results as early as 25 GW. Our study not only expands the VANGL1 mutational spectrum but also sheds light on the important role of the VANGL1 P384R variant in human development.

Understanding False Negative in Prenatal Testing

A false negative can happen in many kinds of medical tests, regardless of whether they are screening or diagnostic in nature. However, it inevitably poses serious concerns especially in a prenatal setting because its sequelae can mark the birth of an affected child beyond expectation. False negatives are not a new thing because of emerging new tests in the field of reproductive, especially prenatal, genetics but has occurred throughout the evolution of prenatal screening and diagnosis programs. In this paper we aim to discuss the basic differences between screening and diagnosis, the trade-offs and the choices, and also shed light on the crucial points clinicians need to know and be aware of so that a quality service can be provided in a coherent and sensible way to patients so that vital issues related to a false negative result can be appropriately comprehended by all parties.

Gene Environment Interactions in the Etiology of Neural Tube Defects

Human structural congenital malformations are the leading cause of infant mortality in the United States. Estimates from the United States Center for Disease Control and Prevention (CDC) determine that close to 3% of all United States newborns present with birth defects; the worldwide estimate approaches 6% of infants presenting with congenital anomalies. The scientific community has recognized for decades that the majority of birth defects have undetermined etiologies, although we propose that environmental agents interacting with inherited susceptibility genes are the major contributing factors. Neural tube defects (NTDs) are among the most prevalent human birth defects and as such, these malformations will be the primary focus of this review. NTDs result from failures in embryonic central nervous system development and are classified by their anatomical locations. Defects in the posterior portion of the neural tube are referred to as meningomyeloceles (spina bifida), while the more anterior defects are differentiated as anencephaly, encephalocele, or iniencephaly. Craniorachischisis involves a failure of the neural folds to elevate and thus disrupt the entire length of the neural tube. Worldwide NTDs have a prevalence of approximately 18.6 per 10,000 live births. It is widely believed that genetic factors are responsible for some 70% of NTDs, while the intrauterine environment tips the balance toward neurulation failure in at risk individuals. Despite aggressive educational campaigns to inform the public about folic acid supplementation and the benefits of providing mandatory folic acid food fortification in the United States, NTDs still affect up to 2,300 United States births annually and some 166,000 spina bifida patients currently live in the United States, more than half of whom are now adults. Within the context of this review, we will consider the role of maternal nutritional status (deficiency states involving B vitamins and one carbon analytes) and the potential modifiers of NTD risk beyond folic acid. There are several well-established human teratogens that contribute to the population burden of NTDs, including: industrial waste and pollutants [e.g., arsenic, pesticides, and polycyclic aromatic hydrocarbons (PAHs)], pharmaceuticals (e.g., anti-epileptic medications), and maternal hyperthermia during the first trimester. Animal models for these teratogens are described with attention focused on valproic acid (VPA; Depakote). Genetic interrogation of model systems involving VPA will be used as a model approach to discerning susceptibility factors that define the gene-environment interactions contributing to the etiology of NTDs.

Tethered spinal cord among individuals with myelomeningocele: an analysis of the National Spina Bifida Patient Registry

OBJECTIVE

The aims of this study were to review the National Spina Bifida Patient Registry (NSBPR) data set to study the rates of tethered spinal cord release (TCR) among patients with myelomeningocele and variability between centers, to compare TCR rates between males and females, and to study the relationships between TCR rates and other condition-specific characteristics.

METHODS

The NSBPR registry was queried to identify all patients with myelomeningocele. TCR rates were calculated over time using survival analyses; rates between centers and between males and females were compared. Cox proportional hazards models were constructed to identify relationships between TCR rates and sex, functional lesion level, ambulation status, treated hydrocephalus, and prior Chiari decompression.

RESULTS

Of 6339 patients with information about their operations, 1366 (21.5%) underwent TCR, with significant variability between centers. The majority (75.8%) underwent a single TCR. The annual TCR rate was linear between birth and 13 years (1.8%/year) but declined sharply from 14 to 21 years (0.7%/year). There was no period of time at which the TCR rate accelerated. There were no significant differences in TCR rates between males and females. TCR rate was not related to functional lesion level but was lower among nonambulators compared with community ambulators (p = 0.005) and among those with treated hydrocephalus (HR 0.30, p < 0.001), and higher among those having prior Chiari decompression (HR 1.71, p < 0.001).

CONCLUSIONS

These results extend the results of prior single-institution studies, demonstrate significant treatment variability between institutions, and challenge the traditional concept that tethering is related to spinal cord stretching due to spinal growth.

Surgical repair of a meningoencephalocoele in a kākāpō (Strigops habroptilus)

CASE HISTORY

A kākāpō (Strigops habroptilus) chick hatched on an off-shore island of New Zealand with a small white mass protruding through the cranial skin of the head. The chick's growth followed a normal pattern for kākāpō but at 3 weeks of age the cranium mass was non-reducible and fixed in place and the chick was removed from the island for diagnostic imaging and hand-rearing.

CLINICAL FINDINGS AND TREATMENT

A computed tomography (CT) examination revealed a full-thickness circular defect in the central cranium with suspected herniation of brain and dura. Surgery was performed at 37 days of age, and the herniated dura was dissected from the open fontanelle. Attempts to reduce the herniated tissue were unsuccessful, so the herniated dura and cortex were clamped and resected. The dura was closed and the periosteum of the skull was scarified and monofilament polypropylene mesh was secured tautly over the fontanelle. The mesh graft was infused with autologous bone marrow harvested from the ulna in an attempt to stimulate osteogenesis in the mesh repair. The skin flap was then closed. Post-operative recovery and healing were without complication. A CT examination 4 weeks after surgery showed no recurrence of the hernia, and a composite of mesh and scar over the open fontanelle which had reduced in diameter. The chick was released back onto an off-shore island with a radio transmitter and it continues to be monitored regularly.

PATHOLOGICAL FINDINGS

The tissue resected at surgery consisted of a cylindrical core of cerebral parenchyma overlain by a mildly hyperplastic epidermis, and large amounts of oedematous fibrovascular tissue arising from the leptomeninges.

DIAGNOSIS

Rostral parietal meningoencephalocoele.

CLINICAL RELEVANCE

This is the first report of successful surgical resolution of a meningoencephalocoele in any bird. Techniques from human neurosurgery were adapted for the unique anatomical features of the avian skull. The risks of the procedure included increased intra-cranial pressure resulting in anaesthetic complications or death, cerebrospinal fluid leakage, meningitis or recurrence of the meningoencephalocoele. In the longer term, there was a risk of developmental deficits in cognition or behaviour. None of these complications eventuated in the short to medium term, probably due to the small size of the meningoencephalocoele.

Loss-of-function or gain-of-function variations in VINCULIN (VCL) are risk factors of human neural tube defects

Background

Neural tube defects (NTDs) are severe birth defects resulting from the failure of neural tube closure during embryogenesis. Both genetic and environmental factors contribute to the occurrence of NTDs and the heritability of NTDs is approximately 70%. As a key component of focal adhesions, Vinculin (VCL) plays pivotal roles in cell skeleton remodeling and signal transduction. Vcl deficient mice displayed NTD, but how VCL variants contribute to human NTDs has not been addressed yet.

Methods

We screened VCL variants in a Chinese cohort of 387 NTDs and 244 controls by targeted next‐generation sequencing.

Results

We identified four case‐specific VCL variations (p.M209L, p.D256fs, p.L555V and p.R586Q). VCL p.D256fs and p.L555V are novel variations that have never been reported. Our analysis revealed that p.D256fs is a loss‐of‐function variant, while p.L555V showed a gain of function in planner cell polarity (PCP) pathway regulation and cell migration, probably due to its enhanced protein stability.

Conclusion

Our study reports human NTD specific novel variations in VCL and provides the functional evaluation of VCL variants related to the etiology of human NTDs.