Prenatal ultrasound evaluation of segmental level of neurological lesion in fetuses with myelomeningocele: development of a new technique

Ultrasound assessment of bladder and motor function in fetuses with open spina bifida: cohort study

OBJECTIVES

Open spina bifida (OSB) is associated with lower limb and bladder dysfunction. We documented bladder function and lower limb motor function on ultrasound throughout gestation in a cohort of fetuses with OSB. The association of the prenatal findings with postnatal dysfunction was investigated, along with the impact of talipes on pre- and postnatal motor function.

METHODS

A prospective cross-sectional cohort study was performed including all fetuses with isolated OSB, which were assessed at the University Hospitals Leuven between July 2015 and December 2019. The anatomical level of the lesion was determined on three-dimensional ultrasound. Bladder volumes were also measured on three-dimensional ultrasound and filling-voiding changes (flow) were calculated and compared to gestational-age-matched control fetuses imaged for this study (matched 1:1). The fetal motor function level was determined on ultrasound based on joint movement of the hip, knee, ankle and toes. Postnatal bladder function was assessed by questionnaire and cystography at 1 year of age. The predictive ability of prenatal anatomical and functional levels for postnatal lower limb function was assessed. Lastly, the presence of talipes was assessed as a prognostic factor.

RESULTS

We included 122 examinations from 69 OSB fetuses. Bladder volumes were smaller in fetuses with OSB compared to controls and the difference increased with advancing gestational age. There was no association of bladder volume and urinary flow with the level of the lesion, nor was there a measurable effect of prenatal surgery on fetal bladder volume. Postnatal urinary reflux was more likely in children with a smaller bladder volume and lower urinary flow rate at 24 weeks' gestation. Lower limb motor dysfunction was more frequent at higher gestational ages. In-utero motor function was a better predictor of postnatal motor function than the anatomical level of the lesion in fetuses that underwent surgery. Fetuses with talipes performed four levels worse postnatally compared to fetuses without talipes, despite a similar anatomical level of the lesion.

CONCLUSION

In OSB, prior to fetal surgery, bladder volume and urinary flow are already abnormal from early in gestation, independent of the level of the lesion, and may be predictive of postnatal urinary reflux. Motor function impairment can be demonstrated prenatally and is a better predictor of postnatal motor dysfunction than the prenatal anatomical level of the lesion. The presence of talipes adversely impacts postnatal motor function. © 2025 International Society of Ultrasound in Obstetrics and Gynecology.

Implementation of in utero laparotomy-assisted fetoscopic spina bifida repair in two centers in Latin America: rationale for this approach in this region

Background

Spina bifida (SB) is a severe congenital malformation that affects approximately 150,000 infants annually, predominantly in low- and middle-income countries, leading to significant morbidity and lifelong disabilities. In Latin America, the birth prevalence of SB is notably high, often exacerbated by limited healthcare resources and poor access to advanced medical care. The implementation of laparotomy-assisted fetoscopic in-utero SB repair programs in Latin America targets reducing prematurity rates and enabling vaginal births while preserving the benefits of decreased need for hydrocephalus treatment and improved mobility in children.

Objective

This study evaluated the safety, efficacy, and outcomes of laparotomy-assisted fetoscopic in-utero SB repair in Latin America compared to traditional open-hysterotomy methods.

Study design

This retrospective cohort study included 39 cases of laparotomy-assisted fetoscopic in-utero SB repair, with 14 cases from Mexico (2017-2021) and 25 cases from Colombia (2019-2024). These cases were compared to 78 cases from the MOMs trial and 314 from other Latin American centers using traditional open-hysterotomy methods. Statistical analyses included the Student's t-test, Kruskal-Wallis test, and Pearson's chi-square test.

Results

The gestational age (GA) at the time of surgery was significantly higher in fetoscopic centers (26±1.27 weeks) compared to the MOMs trial (23.6±1.42 weeks) and traditional hysterotomy methods (25.4±1 weeks) (P<.001). Mean GA at delivery was significantly earlier in the hysterotomy-based groups than in our fetoscopic group (MOMs: 34.1 [± 3.1] vs open-repair centers in LATAM: 34 [±3002] vs Fetoscopic: 35.3 [± 3.79] weeks; P values=.14 and 0004, respectively). Moreover, and the fetoscopic repair group exhibited a significantly lower rate of spontaneous preterm births (<34 weeks) at 15.8%, compared to 46.2% in the MOMs trial group and 49% in the other Latin American centers using traditional open-hysterotomy methods (P=.004 and .001, respectively). Additionally, the fetoscopic group had higher birthweights (2618±738g) and a lower cesarean delivery rate (65.8%) compared to the other groups (P<.001). Hydrocephalus treatment requirements at 12 months were similar across all groups. No maternal deaths or other outcomes such as pulmonary edema or need for maternal transfusion were noted in the fetoscopic SB repair group.

Conclusion

The laparotomy-assisted fetoscopic SB repair offers a feasible and safer alternative to traditional hysterotomy-based techniques in Latin America. This approach significantly reduces the rates of prematurity and cesarean deliveries, facilitating vaginal births and minimizing maternal morbidity. These findings support the broader adoption of fetoscopic SB repair in regions with a high prevalence of SB and suboptimal perinatal outcomes, underscoring its advantages over hysterotomy-based approaches.

Communicating neurological prognosis in the prenatal period: a narrative review and practice guidelines

Clinicians may face an array of challenges in conducting fetal neurological consultations including prognostic uncertainty, a lack of training in fetal counseling, and limited opportunity to build rapport with families. In this setting, it is critical to employ high-quality, family-centered care to allow expectant parents to make informed decisions. Despite the challenges and gravity of these consultations, there remains limited data outlining best conduct and communication practices. This narrative review aims to summarize relevant literature around counseling within fetal neurology, focusing on three key themes: (1) discussing neurological prognosis and uncertainty, (2) navigating evolving decision making, (3) recognizing bias and understanding patient context. We provide practical recommendations to clinicians conducting fetal neurological counseling and outline future research priorities. IMPACT: Fetal neurological conditions can have a significant impact on child short- and long-term health outcomes. Prenatal consultations are an important venue to discuss information regarding fetal prognosis and decision making with expectant parents. However, there is limited evidence supporting best communication practices within this setting. This review summarizes current literature around expectant parent prognostic communication preferences and outlines practical recommendations and priorities for future research.

Parental Management Choices and Discordant Ultrasound Findings in Referrals for Fetal Spina Bifida

OBJECTIVE

The severity of spina bifida aperta can be assessed prenatally by ultrasound. Morphological findings assist parents in choosing between management options. We aimed to document those management choices since the introduction of fetal surgery, and compare initial ultrasound findings prior to referral to findings in a fetal surgery center.

METHOD

Single center cohort study of 245 consecutive fetuses with a second-trimester diagnosis of SBA. Data included nature of referral (for assessment or for surgery), condition-specific findings on ultrasound, and further management. We compared the reported findings on the initial ultrasound to ours for the presence of hindbrain herniation, lesion level, ventricular width, kyphosis, leg movement, and club feet.

RESULTS

Seventy-two percent (n = 177) of fetuses met the eligibility criteria for surgery; in 60% (n = 106) parents opted for fetal surgery. Of 136 patients specifically referred for surgery, 27 were ineligible (20%). Of the others, 93 proceeded with surgery. In up to 28% (n = 30) of surgery referrals, eligibility criteria such as lesion level (n = 30, 28%) or leg movement (72%, n = 78) as severity indicators were not reported.

CONCLUSION

Fetal surgery uptake was high in patients referred for surgery. Second assessment in a fetal surgery center often reveals additional relevant information.

Role of Amniotic Fluid Toxicity in the Pathophysiology of Myelomeningocele: A Narrative Literature Review

Myelomeningocele is a birth defect whose clinical manifestations are due both to incomplete neural tube closure and the progressive destruction of exposed neuroepithelium during pregnancy. Two hypotheses have been formulated to explain the spinal cord damage in utero: mechanical trauma and chemical factors. The objective of this review was to summarize the current insights about the potential role of amniotic fluid in spinal cord damage in myelomeningocele. Numerous histological and clinical data on animals and humans strongly suggest a progressive degeneration of neural tissue including loss of neural cells, astrogliosis, inflammation, and loss of normal architecture. However, few data have been published about the direct toxicity of amniotic fluid in this neural degeneration, including the potentially toxic effect of meconium. Finally, the chemical and cellular modifications of amniotic fluid composition in myelomeningocele could reflect both the process (toxic effect of meconium) and the consequences of neuroepithelium destruction (release of neural cells). Fetal surgery not only stops the leakage of the cerebrospinal fluid but also reduces the toxic effect of amniotic fluid by restoring the intrauterine environment. Identification of amniotic fluid neurotoxic factors could lead to the development of therapeutic agents designed to protect spinal tissue and improve fetal myelomeningocele outcomes.

Noggin-Loaded PLA/PCL Patch Inhibits BMP-Initiated Reactive Astrogliosis

Myelomeningocele (MMC) is a congenital birth defect of the spine and spinal cord, commonly treated clinically through prenatal or postnatal surgery by repairing the unclosed spinal canal. Having previously developed a PLA/PCL polymer smart patch for this condition, we aim to further expand the potential therapeutic options by providing additional cellular and biochemical support in addition to its mechanical properties. Bone morphogenetic proteins (BMPs) are a large class of secreted factors that serve as modulators of development in multiple organ systems, including the CNS. We hypothesize that our smart patch mitigates the astrogenesis induced, at least partly, by increased BMP activity during MMC. To test this hypothesis, neural stem or precursor cells were isolated from rat fetuses and cultured in the presence of Noggin, an endogenous antagonist of BMP action, with recombinant BMPs. We found that the developed PLA/PCL patch not only serves as a biocompatible material for developing neural stem cells but was also able to act as a carrier for BMP-Notch pathway inhibitor Noggin, effectively minimizing the effect of BMP2 or BMP4 on NPCs cultured with the Noggin-loaded patch.

Imaging Fetal Spine Malformations in the Context of In Utero Surgery

This review covers the embryology, definition, and diagnosis of open spinal dysraphism with a focus on fetal ultrasound and MR imaging findings. Differentiating open versus closed spinal dysraphic defects on fetal imaging will also be discussed. Current fetal surgery practices and imaging findings in the context of fetal surgery are also reviewed.

Ambulation after in-utero fetoscopic or open neural tube defect repair: predictors for ambulation at 30 months

OBJECTIVES

To compare the ambulatory status of a cohort of children who had undergone prenatal repair of an open neural tube defect (ONTD) using one of two different methods (fetoscopic or open hysterotomy) with that of a cohort who had undergone postnatal repair, and to identify the best predictors of ambulation at 30 months of age.

METHODS

This was a retrospective review of a cohort of children who underwent ONTD repair either prenatally (n = 110), by fetoscopic surgery (n = 73) or open hysterotomy surgery (n = 37), or postnatally (n = 51), in a single tertiary hospital between November 2011 and May 2023. The cohort comprised a consecutive sample of cases who had undergone ONTD repair in-utero following Management of Myelomeningocele Study (MOMS) trial criteria and cases who had undergone postnatal repair, meeting the same criteria, which were also followed up after birth at the same institution. Motor function assessment by ultrasound was recorded at referral, 6 weeks after prenatal repair, or after referral in postnatally repaired cases, and at the last ultrasound scan before delivery. Clinical examinations to assess motor function at birth and at 12 months were retrieved from records. Intact motor function was defined as first sacral myotome (S1) motor function. Ambulatory status data at each follow-up visit were collected. The proportion of children who were able to walk independently after 30 months of age was compared between those who had undergone fetoscopic vs open prenatal surgery and between prenatal (by either fetoscopic or open surgery) and postnatal ONTD repair. Logistic regression analyses were performed to identify predictors for independent ambulation.

RESULTS

After 30 months, the proportion of infants who were able to walk independently was higher in prenatally vs postnatally repaired cases (51.8% vs 15.7%, P < 0.01), and there was no difference between those with fetoscopic (52.1%) vs open (51.4%) prenatal repair (P = 0.66). In the prenatally repaired group, having intact motor function at 12 months (adjusted odds ratio (aOR), 9.14 (95% CI, 2.64-31.63), P < 0.01) and at birth (aOR, 4.50 (95% CI, 1.21-16.80), P = 0.02) were significant predictors of independent walking at 30 months; an anatomical level of lesion below L2 at referral (aOR, 1.83 (95% CI, 1.30-2.58), P = 0.01) and female gender (aOR, 3.51 (95% CI, 1.43-8.61), P < 0.01) were also predictive for this outcome.

CONCLUSIONS

Prenatally repaired cases of ONTD have a better chance of being able to walk independently at 30 months than do those who undergo postnatal repair. In patients with prenatally repaired ONTD, ambulatory status at 30 months can be predicted by observing a low lesion level at referral (below L2) and intact motor function postnatally. These results have implications for parental counseling and planning for supportive therapy in pregnancies affected by ONTD. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Proposal for standardized prenatal assessment of fetal open dysraphisms by the European reference network for Intellectual disability, TeleHealth, Autism and Congenital Anomalies (ITHACA) and eUROGEN

Open dysraphisms, that is, myelomeningocele and myeloschisis, are rare diseases associated with a risk of severe disability, including lower limb motor and sensory deficiency, sphincter deficiency, and potential intellectual deficiency. Open dysraphism is diagnosed in Europe in 93.5% of cases. In case of suspicion of fetal open dysraphism, a detailed fetal morphologic assessment is required to confirm the diagnosis and exclude associated structural anomalies, as well as genetic assessment. In case of isolated fetal open dysraphism, assessment of prognosis is based on fetal imaging including the level of the lesion, the presence or not of a sac, the presence and nature of intra cranial anomalies, and the anatomical and functional evaluation of the lower extremities. Based on these biomarkers, a personalized prognosis as well as comprehensive information about prenatal management alternatives will allow parents to decide on further management options. Standardization of prenatal assessment is essential to compare outcomes with benchmark data and make assessment of surgical innovation possible. Herein, we propose a protocol for the standardized ultrasound assessment of fetuses with isolated open dysraphism.

Prenatal diagnosis and postnatal outcome of closed spinal dysraphism

OBJECTIVE

To evaluate the prenatal diagnosis of closed dysraphism (CD) and its correlation with postnatal findings and neonatal adverse outcomes.

METHODS

A retrospective cohort study including pregnancies diagsnosed with fetal CD by prenatal ultrasound (US) and magnetic resonance imaging (MRI) at a single tertiary center between September 2011 and July 2021.

RESULTS

CD was diagnosed prenatally and confirmed postnatally in 12 fetuses. The mean gestational age of prenatal imaging was 24.2 weeks, in 17% the head circumference was ≤fifth percentile and in 25% the cerebellar diameter was ≤fifth percentile. US findings included banana sign in 17%, and lemon sign in 33%. On MRI, posterior fossa anomalies were seen in 33% of cases, with hindbrain herniation below the foramen magnum in two cases. Mean clivus-supraocciput angle (CSA) was 74°. Additional anomalies outside the CNS were observed in 50%. Abnormal foot position was demonstrated prenatally in 17%. Neurogenic bladder was present in 90% of patients after birth.

CONCLUSION

Arnold Chiari II malformation and impaired motor function can be present on prenatal imaging of fetuses with CD and may be associated with a specific type of CD. Prenatal distinction of CD can be challenging. Associated extra CNS anomalies are frequent and the rate of neurogenic urinary tract dysfunction is high.

Prenatal imaging of the normal and abnormal spinal cord: recommendations from the Fetal Task Force of the European Society of Paediatric Radiology (ESPR) and the European Society of Neuroradiology (ESNR) Pediatric Neuroradiology Committee

Spinal dysraphisms are amenable to diagnosis in utero. The prognosis and the neonatal management of these conditions differ significantly depending on their types, mainly on the distinction between open and closed defects. A detailed evaluation not only of the fetal spine, but also of the brain, skull, and lower limbs is essential in allowing for the right diagnosis. In this article, recommendations from the Fetal Task Force of the European Society of Paediatric Radiology (ESPR) and the European Society of Neuroradiology (ESNR) Pediatric Neuroradiology Committee will be presented. The aim of this paper is to review the imaging features of the normal and abnormal fetal spinal cord, to clarify the prenatal classification of congenital spinal cord anomalies and to provide guidance in their reporting.

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.

Biocellulose patch technique for fetoscopic repair of open spina bifida in twin pregnancy

OBJECTIVES

Twin pregnancy is currently an exclusion criterion for prenatal repair of open spina bifida (OSB). The main objective of this study was to report on our experience of treating twin pregnancies with OSB using the skin-over-biocellulose for antenatal fetoscopic repair (SAFER) technique. We also discuss reconsideration of the current exclusion criteria for fetal OSB repair.

METHODS

Eight fetuses with OSB from seven twin pregnancies underwent successful prenatal repair. Six pregnancies were dichorionic diamniotic with only one twin affected, and one was monochorionic diamniotic with both twins affected. Percutaneous fetoscopy was performed under CO2 insufflation of the sac of the affected twin. Neurosurgical repair was performed using a biocellulose patch to protect the placode, with the skin sutured to hold the patch in place, with or without a myofascial flap. Neurodevelopment was assessed using the pediatric evaluation of disability inventory scale in babies older than 6 months of adjusted age, whereas the Alberta scale was used for babies younger than 6 months of adjusted age.

RESULTS

All 14 fetuses were liveborn and none required additional repair. Gestational age at surgery ranged from 27.3 to 31.1 weeks, and gestational age at birth ranged from 31.6 to 36.0 weeks. Four out of eight affected twins developed sepsis, but had a good recovery. No sequela of prematurity was found in any of the unaffected twins. Short-term neurodevelopment was normal in all evaluated unaffected twins (5/5) and in all but one affected twins (7/8). In the affected group, only one baby required ventriculoperitoneal shunt placement.

CONCLUSIONS

Prematurity is frequent after fetal surgery, and the risk is increased in twin pregnancy. Nevertheless, prenatal surgery using the SAFER technique is feasible, with low risk to both twins and their mother when performed by a highly experienced team. Long-term cognitive assessment of the unaffected twin is needed. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Implementation and Assessment of a Laparotomy-Assisted Three-Port Fetoscopic Spina Bifida Repair Program

Open spina bifida (OSB) is a congenital, non-lethal malformation with multifactorial etiology. Fetal therapy can be offered under certain conditions to parents after accurate prenatal diagnostic and interdisciplinary counseling. Since the advent of prenatal OSB surgery, various modifications of the original surgical techniques have evolved, including laparotomy-assisted fetoscopic repair. After a two-year preparation time, the team at the University of Giessen and Marburg (UKGM) became the first center to provide a three-port, three-layer fetoscopic repair of OSB via a laparotomy-assisted approach in the German-speaking area. We point out that under the guidance of experienced centers and by intensive multidisciplinary preparation and training, a previously described and applied technique could be transferred to a different setting.

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.

Assessment of lower limb trophism in fetuses with open spina bifida using fractional thigh volume of three-dimensional ultrasound

OBJECTIVE

To assess the trophism of the lower limbs of fetuses with open spina bifida using fractional thigh volume (TVOL) of three-dimensional (3D) ultrasound.

METHODS

A prospective cross-sectional study was carried out with normal fetuses and with open spina bifida (myelomeningocele and rachischisis) at 26 weeks' gestation. The TVOL (delimitation of five cross-sectional areas of the middle portion of the limb) was evaluated, as well as the subjective assessment of hypotrophy and lower limb movement.

RESULTS

Thirty-one fetuses with open spina bifida, 21 with myelomeningocele and 10 with rachischisis, and 51 normal fetuses were included. There were no significant differences in the TVOL between normal and spina bifida fetuses (p = 0.623), as well as between normal fetuses, with myelomeningocele and with rachischisis (p = 0.148). There was no significant difference in the TVOL of fetuses with spina bifida with or without lower limb hypotrophy (p = 0.148). Fetuses with spina bifida and with lower limb movement had higher TVOL values than fetuses without lower limb movement (p = 0.002).

CONCLUSION

There were no significant differences in the TVOL measurement of normal and spina bifida fetuses (rachischisis and myelomeningocele). Fetuses with spina bifida without spontaneous movement of the lower limbs had lower TVOL values.

Advances in Fetal Surgical Repair of Open Spina Bifida

Spina bifida remains a common congenital anomaly of the central nervous system despite national fortification of foods with folic acid, with a prevalence of 2-4 per 10,000 live births. Prenatal screening for the early detection of this condition provides patients with the opportunity to consider various management options during pregnancy. Prenatal repair of open spina bifida, traditionally performed by the open maternal-fetal surgical approach through hysterotomy, has been shown to improve outcomes for the child, including decreased need for cerebrospinal fluid diversion surgery and improved lower neuromotor function. However, the open maternal-fetal surgical approach is associated with relatively increased risk for the patient and the overall pregnancy, as well as future pregnancies. Recent advances in minimally invasive prenatal repair of open spina bifida through fetoscopy have shown similar benefits for the child but relatively improved outcomes for the pregnant patient and future childbearing.

The Lower Limb Movements of the Fetus in Uterus: A Narrative Review

The fetus movements play an important role in fetal well-being. With the continuous advancement of real-time scanning machines, it is feasible to observe the fetus movement in detail. The characteristics of fetal lower limb movements in prenatal examination have not been systematically investigated. This review proposes the patterns of fetal lower limb movements, the maternal influence on fetal lower limb movements, and the application of fetal lower limb movements for the diagnosis of prenatal diseases. A systematic search of literature on the lower limb movements of the fetus in uterus was performed in the databases, namely, Web of Science and Scopus. Thirty-four publications were selected. This review demonstrates that isolated fetal lower limb movements are rare and always accompanied with the movements of other body segments. Detection of the presence of fetal leg movements seems to be of no diagnostic value for fetuses with prenatal diseases. The isolated lower limb movement was statistically significant different between fetuses of low- and high-risk pregnant women. The coordinated movements of the fetal lower limbs and other parts should be considered when analyzing fetal movements in the future study.

Fetal MRI prior to intrauterine surgery of open neural tube defects: What does the radiologist need to know

The management of myelomeningocele study trial showed significant prognostic improvement in fetal repair before 26 weeks of gestation. Hence, surgery in utero represents the best treatment option for open-neural tube defects (NTDs). Fetal surgery of open-NTDs has specific inclusion and exclusion criteria, which can be adequately studied with fetal MRI. The main concern: the spine (spinal defects other than Myelomeningocele and Myeloschisis, the level of the lesion higher than T1 or lower than S1 and the degree of kyphosis ≥ 30°), the skull/brain (no cerebellum herniation and Chiari II malformation and the presence of any intracranial abnormality unrelated to open NTDs), the uterus (cervix length less than 2 cm, multiple gestations and placental and uterine abnormalities) and any other fetal abnormality not attributed to spinal defect. In this review, we describe the fundamental role of fetal MRI in supporting therapeutic decisions in pre-surgery intrauterine planning through the accurate and comprehensive description of findings, providing a proposal of a structured report. In addition, we describe how post-surgical MRI is important in investigating the effectiveness of surgery and detecting repairing complications.

A comparison of the accuracy of fetal magnetic resonance imaging and ultrasonography for the diagnosis of fetal congenital malformations of the spine and spinal cord

PURPOSE

To determine the diagnostic value of fetal magnetic resonance imaging (MRI) for congenital spine/spinal cord malformations.

METHODS

This single-center retrospective study included 120 cases of fetal spine/spinal cord abnormalities detected using fetal ultrasonography (US) and further examined by fetal MRI between 2016 and 2020. Cases were divided into three groups (congenital spine, spinal cord, and spine + spinal cord malformations) based on US assessment. We analyzed the accuracy of fetal US and MRI relative to postnatal imaging.

RESULTS

The diagnostic accuracy of fetal MRI for fetal spinal cord, spine, and spine + spinal cord malformations was 86.2% (25/29), 89.4% (42/47), and 86.3% (38/44), respectively, and the corresponding rates for fetal US were 51.7% (15/29), 87.2% (41/47), and 68.2% (30/44). The diagnostic accuracy did not differ between fetal MRI and US for congenital spine malformations (P > 0.05); for congenital spinal cord malformations and congenital spine+spinal cord malformations, the diagnostic accuracy was significantly higher for fetal MRI than for fetal US (P < 0.05).

CONCLUSIONS

Fetal MRI is effective in the assessment of congenital spine/spinal cord malformations. It can yield information that supplements US findings, especially for congenital spinal cord malformations, and can improve the accuracy of fetal diagnosis. This article is protected by copyright. All rights reserved.

Determination of anatomic level of myelomeningocele by prenatal ultrasound

PURPOSE

Ultrasound is the primary method for prenatal identification of myelomeningocele and is critical to prognostication and treatment planning. No study has considered the degree of inaccuracy of prenatal US lesion level estimates and anatomic lesion level on postnatal imaging using the weighted kappa coefficient (κw), nor the impact of maternal BMI on agreement. We examined the accuracy of prenatal ultrasound lesion level estimation in a cohort of patients with myelomeningocele using κw and determined whether BMI influenced accuracy.

METHODS

The study is a retrospective review including patients born 2011-2019 who had prenatal imaging and primary myelomeningocele closure at a single institution. Lesion levels from prenatal ultrasound and postnatal imaging studies were analyzed for agreement at exact level, within 1 level, and within 2 levels using κw. Maternal BMI was examined for correlation with accuracy.

RESULTS

Fifty-seven patients met inclusion criteria. Mean BMI was 31.2. There was no association between maternal BMI and agreement at any level. Lesion level on prenatal ultrasound agreed with postnatal imaging to the exact level in 13 (22.8%) cases, within 1 level in 38 (66.7%) cases, and within 2 levels in 50 (87.7%) cases. Weighted kappa showed moderate agreement at exact level (κ_w = 0.494) and substantial agreement within 1 (κ_w = 0.761) and 2 levels (κ_w = 0.902).

CONCLUSION

Weighted kappa adds confidence for clinical decision making by accounting for accuracy. Prenatal ultrasound is a reliable and accurate method of determining lesion level with near-perfect agreement to postnatal imaging within 2 spinal levels. Maternal BMI may not influence lesion level determination after initial diagnosis.

Computation of Fetal Kicking in Various Fetal Health Examinations: A Systematic Review

Fetal movement has always been considered an essential indicator to evaluate the health of the unborn fetus. Many factors affect fetal movement. The frequency of fetal kicking is an important measurement of whether fetal development is progressing and healthy. Various instruments and methods of detecting fetal movement have been used and each method has its advantages and disadvantages. Although limited by the fetal environment in utero, the finite element method and musculoskeletal model can be used to calculate fetal lower limb movement. This review aims to summarize the current detection techniques for fetal movement, especially in the lower limbs. These will be outlined by describing the different measurements of fetal movement, and the related biomechanical analyses of fetal lower limb skeletogenesis and the associated muscular development to better evaluate and calculate the movements of the fetus in the womb.

Measurement of the Area and Circumference of the Leg: Preliminary Results of a New Method for Estimating Leg Muscle Trophism in Fetuses With Open Lumbosacral Spina Bifida

OBJECTIVE

To standardize a new technique to evaluate the fetal leg muscle trophism by measuring the area and circumference, and comparing this technique between normal and fetuses with open lumbosacral spina bifida (SB).

METHODS

Observational cross-sectional study was carried out on pregnant women with 26 weeks who were divided into two groups: Group I-fetuses with diagnosis of open lumbosacral SB; Group II-normal fetuses (control). In fetuses with SB, subjective evaluation of the lower limbs was performed (muscle echogenicity and leg movements). To estimate the leg muscle trophism, the measurement of the area and circumference of the leg were standardized, and the reproducibility of this method was performed.

RESULTS

Thirty-one fetuses with open lumbosacral SB and 51 normal fetuses were evaluated. The measurements of the area and circumference of the leg proved to be highly reproducible (intraclass correlation coefficient-ICC > 0.95). The leg area and circumference measurements were statistically lower in the SB group than in the control group (p < .001). When subjective ultrasound assessment demonstrated hypotrophy of the lower limbs, the measurements of the area and circumference of the leg were statistically lower when compared to normal fetuses (p < .001). Fetuses with open SB with abnormal lower limb movements had lower measurements of the area and circumference of the leg than fetuses with normal movements (p < .001).

CONCLUSION

A new technique for estimating fetal leg muscle trophism was standardized, which proved to be highly reproducible and was able to show the difference between normal and fetuses with SB.

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.

Time Course Transcriptome Analysis of Spina Bifida Progression in Fetal Rats

A better understanding of the transcriptomic modifications that occur in spina bifida may lead to identify mechanisms involved in the progression of spina bifida in utero and the development of new therapeutic strategies that aid in spinal cord regeneration after surgical interventions. In this study, RNA-sequencing was used to identify differentially expressed genes in fetal spinal cords from rats with retinoic acid-induced spina bifida at E15, E17, and E20. Gene ontology, KEGG, and protein–protein interaction analysis were conducted to predict pathways involved in the evolution of the disease. Approximately 3000, 1000 and 300 genes were differentially expressed compared to the control groups at E15, E17 and E20, respectively. Overall, the results suggest common alterations in certain pathways between gestational time points, such as upregulation in p53 and sonic hedgehog signaling at E15 and E17 and downregulation in the myelin sheath at E17 and E20. However, there were other modifications specific to gestational time points, including skeletal muscle development at E15, downregulated glucose metabolism at E17, and upregulated inflammation at E20. In conclusion, this work provides evidence that gestational age during spina bifida repair may be a significant variable to consider during the development of new regenerative therapeutics approaches.

Percutaneous fetoscopic spina bifida repair: effect on ambulation and need for postnatal cerebrospinal fluid diversion and bladder catheterization

OBJECTIVE

A trial comparing prenatal with postnatal open spina bifida (OSB) repair established that prenatal surgery was associated with better postnatal outcome. However, in the trial, fetal surgery was carried out through hysterotomy. Minimally invasive approaches are being developed to mitigate the risks of open maternal-fetal surgery. The objective of this study was to investigate the impact of a novel neurosurgical technique for percutaneous fetoscopic repair of fetal OSB, the skin-over-biocellulose for antenatal fetoscopic repair (SAFER) technique, on long-term postnatal outcome.

METHODS

This study examined descriptive data for all patients undergoing fetoscopic OSB repair who had available 12- and 30-month follow-up data for assessment of need for cerebrospinal fluid (CSF) diversion and need for bladder catheterization and ambulation, respectively, from eight centers that perform prenatal OSB repair via percutaneous fetoscopy using a biocellulose patch between the neural placode and skin/myofascial flap, without suture of the dura mater (SAFER technique). Univariate and multivariate logistic regression analyses were used to examine the effect of different factors on need for CSF diversion at 12 months and ambulation and need for bladder catheterization at 30 months. Potential cofactors included gestational age at fetal surgery and delivery, preoperative ultrasound findings of anatomical level of the lesion, cerebral lateral ventricular diameter, lesion type and presence of bilateral talipes, as well as postnatal findings of CSF leakage at birth, motor level, presence of bilateral talipes and reversal of hindbrain herniation.

RESULTS

A total of 170 consecutive patients with fetal OSB were treated prenatally using the SAFER technique. Among these, 103 babies had follow-up at 12 months of age and 59 had follow-up at 30 months of age. At 12 months of age, 53.4% (55/103) of babies did not require ventriculoperitoneal shunt or third ventriculostomy. At 30 months of age, 54.2% (32/59) of children were ambulating independently and 61.0% (36/59) did not require chronic intermittent catheterization of the bladder. Multivariate logistic regression analysis demonstrated that significant prediction of need for CSF diversion was provided by lateral ventricular size and type of lesion (myeloschisis). Significant predictors of ambulatory status were prenatal bilateral talipes and anatomical and functional motor levels of the lesion. There were no significant predictors of need for bladder catheterization.

CONCLUSION

Children who underwent prenatal OSB repair via the percutaneous fetoscopic SAFER technique achieved long-term neurological outcomes similar to those reported in the literature after hysterotomy-assisted OSB repair. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

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.

Impact of the cystic neural tube defects on fetal motor function in prenatal myelomeningocele repairs: A retrospective cohort study

OBJECTIVE

To determine the impact of the lesion type (cystic [myelomeningocele] or flat [myeloschisis]) on the fetal motor function (MF) in cases candidates for prenatal open neural tube defect (ONTD) repair.

METHODS

Retrospective cohort study of patients with ONTD who underwent prenatal repair at a single institution between 2011 and 2019. The lesion type and the measurements of the length and width of the lesions to calculate the surface of the ellipsoid lesion were performed using MR scans. Prenatal MF of the lower extremities was evaluated by ultrasound following a metameric distribution at the time of referral. Intact MF was defined as the observation of plantar flexion of the ankle. Logistic regression was performed to determine the predictive value of the type of lesion for having an intact MF at the time of referral.

RESULTS

103 patients were included at 22.9 (19-25.4) weeks; 65% had cystic and 35% had flat lesions. At the time of referral, there was a higher proportion of cases with an intact MF in the presence of flat lesions (34/36; 94.4%) as compared to cystic lesion (48/67; 71.6%, p < 0.01). When adjusting for gestational age and anatomical level of the lesion, flat ONTD were 3.1 times more likely to be associated by intact motor function (CI%95 [2.1-4.6], p < 0.01) at the time of referral.

CONCLUSION

Cystic ONTD are more likely to be associated with impaired MF at mid-gestation in candidates for prenatal ONTD repair.

Myelomeningocele-Chiari II malformation-Neurological predictability based on fetal and postnatal magnetic resonance imaging

Objective

This systematic comparison between pre‐ and postnatal imaging findings and postnatal motor outcome assesses the reliability of MRI accuracy in the prognostication of the future long‐term (mean, 11.4 years) ambulatory status in a historic group of postnatally repaired myelomeningocele (MMC) cases.

Methods

A retrospective, single‐center study of 34 postnatally repaired MMC patients was performed. We used fetal and postnatal magnetic resonance imaging (MRI) to compare the fetal and postnatal radiological lesion level to each other and to the postnatal ambulatory level as a standard of reference and analyzed Chiari II malformation characteristics.

Results

In 13/15 (87%) and 29/31 (94%) cases, the functional level was equal to or better than the prenatal and postnatal radiological lesion level. A radiological lesion level agreement within two segments could be achieved in 13/15 (87%) patients. A worse than expected functional level occurred in cases with Myelocele (2/3 patients), coexistent crowding of the posterior fossa (2/3 patients) and/or abnormal white matter architecture, represented by callosal dysgenesis (1/3 patients). In all patients (2/2) with a radiological disagreement of more than two segments, segmentation disorders and scoliosis were observed.

Conclusion

Fetal and postnatal MRI are predictive of the long‐term ambulatory status in postnatally repaired MMC patients.

What's already known about this topic?

Fetal and postnatal magnetic resonance imaging (MRI) show a good correlation in identifying the level of the myelomeningocele (MMC) lesion.

Prenatal ultrasound (US) and fetal MRI show a comparable agreement, within two segments, in predicting the short‐term ambulatory status.

What does this study add?

Fetal and postnatal MRI have a good predictive value for the long‐term ambulatory status in patients with postnatal MMC closure.

MMC patients with worse than expected ambulatory status showed signs of vermian displacement and corpus callosum dysgenesis.

In MMC patients with spinal segmentation disorders and scoliosis, there was a major disagreement between fetal and postnatal MRI, specifically with regard to the MMC lesion level.

[Prenatal ultrasound prognostic of myelomeningocele at the era of fetal surgery]

Myelomeningocele (MMC) is a severe congenital condition responsible for motor and sensory impairments of the lower limbs, incontinence and cognitive impairment. Its screening, sometimes as early as the first trimester, is one of the major goals of modern prenatal care, supported by the emergence of prenatal surgery that results in a significant improvement in motor function, ambulation and ventriculoperitoneal shunt rate in patients undergoing in-utero surgery. From screening to pre- and post-operative prognostic evaluation, prenatal ultrasound is now an essential tool in the antenatal management of this condition. Using the multi planar and three-dimensional modes, it can be used to assess the vertebral level of MMC, which remains the key antenatal prognostic marker for motor function and ambulation, incontinence and the need for a ventriculo-peritoneal shunt. A careful and systematic ultrasound examination also makes it possible to assess the severity and progression of ventriculomegaly, to search for associated cerebral, spinal cord or vertebral anomalies, or to rule out exclusion criteria for in-utero surgery such as severe kyphosis or serious cortical anomalies. New tools from post-natal evaluation, such as the "metameric" ultrasound assessment of lower limb mobility, appear to be promising either for the initial examination or after in-utero surgery. Ultrasonography, associated with fetal MRI, cytogenetic and next generation sequencing, now allows a highly customized prognostic evaluation of these fetuses affected by MMC and provides the parents with the best possible information on the expected benefits and limitations of fetal surgery.

Teaching and training the total percutaneous fetoscopic myelomeningocele repair

Skin-over-biocellulose for Antenatal Fetoscopic Repair (SAFER) is a recently developed technique for fully percutaneous fetoscopic repair of myelomeningocele. The formation of a neo-dura mater triggered by the use of a biocellulose patch over the placode obviates the need of primary repair of fetal dura mater, and seems to further improve neurodevelopmental outcome. Insufflation of humidified carbon dioxide into the amniotic cavity requires proper training and a different equipment set from those used in the classic "under-water" fetoscopy. To shorten the learning curve of novice teams, we have developed a structured training course encompassing three critical steps: (1) visiting the proctor center, (2) selection of the first case, and (3) on-site training of the surgical team. Upon the site arrival, there will be: (1) theoretical lecture for all specialists involved in the fetal care, (2) simulation training, and (3) surgical proctoring. Proctor team can take over the surgery if the local team cannot complete. This training course has been successfully used in five different countries: Israel, Chile, Italy, USA and England and all local teams are already performing surgeries solo without any failures or maternal morbidity. Teaching new procedures in fetal medicine is challenging, because of the small number of candidate cases, and the direct relation of good outcomes and the number of cases operated. This proposed training modules may be adopted by other teams that want to embark on this type of novel minimally invasive treatment.

Diagnostic accuracy of prenatal ultrasound in identifying the level of the lesion in fetuses with open spina bifida: A systematic review and meta-analysis

INTRODUCTION

The role of prenatal ultrasound in correctly identifying the level of the lesion in fetuses with open spina bifida has yet to be determined. The primary aim of this systematic review was to report the diagnostic accuracy of ultrasound in determining the level of the lesion in fetuses with open spina bifida. The secondary aim was to elucidate whether prenatal magnetic resonance imaging (MRI) improves the diagnostic performance of prenatal imaging in correctly identifying the level of the lesion.

MATERIAL AND METHODS

Inclusion criteria were studies reporting the agreement between ultrasound, MRI and postnatal or postmortem assessment of fetuses with spina bifida. Agreement was defined as: complete (when the upper level of the lesion detected prenatally was the same recorded at postnatal or postmortem evaluation), within one (when the upper level of the lesion recorded prenatally was within one vertebral body higher or lower than that reported postnatally) and within two vertebral bodies (when the upper level of the lesion recorded prenatally was within two vertebral bodies higher or lower than that reported postnatally or postmortem evaluation). Meta-analyses of proportions were used to combine data.

RESULTS

Fourteen studies (655 fetuses) were included. Ultrasound was able to identify the correct level of the lesion in 40.9% (95% confidence interval [CI] 26.9-55.6) of cases. The upper level of the lesion recorded on ultrasound was within one vertebral body in 76.2% (95% CI 65.0-85.9) of cases and within two segments in 92.4% (95% CI 84.3-97.7). Fetal MRI detected the exact level of the lesion in 42.5% (95% CI 35.9-45.2) of cases; the level of the lesion recorded on MRI was higher in 26.4% (95% CI 20.0-33.3) of cases and lower in 32.4% (95% CI 25.5-39.7) than that confirmed postnatally. The upper level of the lesion recorded on MRI was within one vertebral body in 76.2% (95% CI 65.9-85.2) of cases and within two segments in 94.2% (95% CI 90.2-97.2).

CONCLUSIONS

Both ultrasound and MRI have a moderate diagnostic accuracy in identify the upper level of the lesion in fetuses with open spina bifida.

Imaging of open spinal dysraphisms in the era of prenatal surgery

Over the last decade fetal surgery to repair open spinal dysraphisms has become an acceptable and in some cases desirable alternative to the traditional method of postnatal closure. Fetal MRI is an essential part of the workup in these patients, not only to select the appropriate candidates for fetal surgery but also to guide prenatal counseling and perinatal management. In this article we review current surgical techniques for prenatal repair, relevant imaging findings in the era of fetal surgery, and expected imaging findings of the brain and spine in the fetal and postnatal periods.

Prenatal predictors of motor function in children with open spina bifida: a retrospective cohort study

OBJECTIVE

To identify predictors for intact motor function (MF) at birth and at 12 months of life in babies with prenatally versus postnatally repaired open spina bifida (OSB).

DESIGN

Retrospective cohort study.

SETTING

Texas Children's Hospital, 2011-2018.

POPULATION

Patients who underwent either prenatal or postnatal OSB repair.

METHODS

Prenatal MF of the lower extremities was evaluated by ultrasound following a metameric distribution at the time of diagnosis (US1), 6 weeks postoperatively (or 6 weeks after initial evaluation in postnatally repaired cases) (US2) and at the last ultrasound before delivery (US3). At birth and at 12 months, MF was assessed clinically. Intact MF (S1) was defined as the observation of plantar flexion of the ankle. Results from logistic regression analysis are expressed as odds ratios (95% confidence intervals, P values).

RESULTS

A total of 127 patients were included: 93 with prenatal repair (51 fetoscopic; 42 open hysterotomy repair) and 34 with postnatal repair. In the prenatal repair group, predictors for intact MF at birth and at 12 months included: absence of clubfeet (OR 11.3, 95% CI 3.2-39.1, P < 0.01; OR 10.8 95% CI 2.4-47.6, P < 0.01); intact MF at US1 (OR 19.7, 95% CI 5.0-76.9, P < 0.01; OR 8.7, 95% CI 2.0-38.7, P < 0.01); intact MF at US2 (OR 22, 95% CI 6.5-74.2, P < 0.01; OR 13.5, 95% 3.0-61.4, P < 0.01); intact MF at US3 (OR 13.7, 95% CI 3.4-55.9, P < 0.01; OR 12.6, 95% CI 2.5-64.3, P < 0.01); and having a flat lesion (OR 11.2, 95% CI 2.4-51.1, P < 0.01; OR 4.1, 95% CI 1.1-16.5, P = 0.04). In the postnatal repair group, the only predictor of intact MF at 12 months was having intact MF at birth (OR 15.2, 95% CI 2.0-113.3, P = 0.03).

CONCLUSIONS

The detection of intact MF in utero from mid-gestation to delivery predicts intact MF at birth and at 12 months in babies who undergo prenatal OSB repair.

TWEETABLE ABSTRACT

Detection of intact motor function in utero predicts intact motor function at birth and at 1 year in fetuses who undergo prenatal OSB repair.

A comparison of the accuracy of fetal MRI and prenatal ultrasonography at predicting lesion level and perinatal motor outcome in patients with myelomeningocele

OBJECTIVE

Prenatal imaging has several critical roles in the diagnosis and management of myelomeningocele, including specific family counseling and the selection of fetal surgery or postnatal repair. In this study, the authors compared the accuracy of fetal MRI and prenatal ultrasonography (US) in predicting the spinal lesion level and assessed the correlation between imaging findings and motor function as independently evaluated by a physical therapist (PT) after birth.

METHODS

A retrospective review of demographic and clinical data was performed to identify children who had been treated with postnatal myelomeningocele closure at a single institution between March 2013 and December 2018. Patients were eligible for inclusion if they had all of the following: prenatal US identifying the neural tube defect level, fetal MRI identifying the neural tube defect level, and postoperative PT evaluation identifying the motor deficit level. Statistical analysis was performed using Cohen's kappa coefficient to compare the US- and MRI-demonstrated lesion level and correlate these findings with the motor level assigned postnatally by a PT via manual muscle testing.

RESULTS

Thirty-four patients met the inclusion criteria. The mean gestational age at US was 23.0 ± 4.7 weeks, whereas the mean gestational age at MRI was 24.0 ± 4.1 weeks. The mean time from surgery to the PT evaluation was 2.9 ± 1.9 days. Prenatal US and MRI were in agreement within one spinal level in 74% of cases (25/34, k = 0.43). When comparing the US-demonstrated spinal level with the PT-assigned motor level, the two were in agreement within one level in 65% of cases (22/34, k = 0.40). When comparing MRI-demonstrated spinal level with the PT motor level, the two were in agreement within one level in 59% of cases (20/34, k = 0.37). MRI and US were within two spinal levels of the PT evaluation in 79.4% and 85.3% of cases, respectively. MRI and US agreed within two levels in 97.1% of cases. Prenatal US and MRI were equivalent when comparing the difference between the imaged level and the postnatal motor deficit level (mean level difference: 1.12 ± 1.16 vs 1.17 ± 1.11, p = 0.86).

CONCLUSIONS

Prenatal US and MRI equivalently predicted the postnatal motor deficit level in children with myelomeningocele. These data may be valuable in prenatal prognostication.

Fetal spina bifida: What we tell the parents

Worldwide, about 150 000 infants are born with spina bifida yearly, making this condition one of the most common fetal central nervous system anomalies compatible with life. Over the last decade, major changes have been introduced in the prenatal diagnosis and management of spina bifida. In this review, we provide a brief summary of the current management of fetal spina bifida and present essential information that should be provided to expecting parents when their fetus has been diagnosed with spina bifida. This information is focused around common parental questions, as encountered in our typical clinical practice, to facilitate knowledge translation.

Prenatal regenerative fetoscopic interventions for congenital anomalies

Fetal intervention has progressed in the past two decades from experimental proof-of-concept to practice-adopted, life saving interventions in human fetuses with congenital anomalies. This progress is informed by advances in innovative research, prenatal diagnosis, and fetal surgical techniques. Invasive open hysterotomy, associated with notable maternal-fetal risks, is steadily replaced by less invasive fetoscopic alternatives. A better understanding of the natural history and pathophysiology of congenital diseases has advanced the prenatal regenerative paradigm. By altering the natural course of disease through regrowth or redevelopment of malformed fetal organs, prenatal regenerative medicine has transformed maternal-fetal care. This review discusses the uses of regenerative medicine in the prenatal diagnosis and management of three congenital diseases: congenital diaphragmatic hernia, lower urinary tract obstruction, and spina bifida.

In Vivo Evaluation of Novel PLA/PCL Polymeric Patch in Rats for Potential Spina Bifida Coverage

BACKGROUND

Current therapeutic materials for spina bifida repair showed a limited number of options in the market, and none of them have all the requirements as the ideal patch. In fact, sometimes the surgical procedures pose substantial challenges using different patches to fully cover the spina bifida lesion. For this purpose, a tailored patch made of poly (L-lactic acid) and poly (ε-caprolactone) blend was designed and validated in vitro to accomplish all these requirements but was never tested in vivo.

MATERIAL AND METHODS

In our present study, the designed patch was analyzed in terms of rejection from the animal when implanted subcutaneously and as a dural substitute in the spinal cord. Inflammatory reaction (Iba1), astrogliosis (GFAP), was analyzed and functional interaction with spinal cord tissue assessing the (%motor-evoked potentials /compound motor action potential) by electrophysiology.

RESULTS

No evidence of adverse or inflammatory reactions was observed in both models of subcutaneous implantation, neither in the neural tissue as a dural substitute. No signs of astrogliosis in the neural tissue were observed, and no functional alteration with improvement of the motor-evoked potential's amplitude was detected after 4 wk of implantation as a dural substitute in the rat spinal cord.

CONCLUSIONS

Designed patch used as a dural substitute will apparently not produce inflammation, scar formation, or tethering cord and not induce any adverse effect on regular functions of the spinal cord. Further studies are needed to evaluate potential improvements of this novel polymeric patch in the spinal cord regeneration using spina bifida models.

Antenatal ultrasound compared to MRI evaluation of fetal myelomeningocele: a prenatal and postnatal evaluation

Background Spina bifida affects 0.5-1 in 1000 pregnancies in the United States and is often diagnosed in the mid-second trimester. The objective of the study was to directly compare ultrasounds (US) and magnetic resonance imaging (MRI) obtained in the antenatal period in the diagnosis and localization of fetal myelomeningocele (MMC) and compare these with the postnatal outcomes of these infants Methods A retrospective analysis of patients referred to the Fetal Care Center at the Cleveland Clinic from 2005 to 2017. US and MRIs were obtained from the Cleveland Clinic electronic medical record. Infants were followed-up at an interdisciplinary myelomeningocele pediatrics clinic. Results MRI and US varied in correlation with physical exam at the time of birth and surgery. While no differences were detected in demographics, pregnancy outcomes or pediatric outcomes, it was noted that the majority of patients developed neurogenic bladders irrespective of the lesion level. Conclusion MRI is not superior to US in the diagnosis of MMC. Pregnancies complicated by MMC do not vary in morbidity, and pediatric outcomes remain similar regardless of the lesion level. This data provides additional information for the counseling of patients when faced with this antenatal diagnosis.

Spinal Dysraphia, Chiari 2 Malformation, Unified Theory, and Advances in Fetoscopic Repair

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

Fetal surgery for spina bifida aperta

Spina bifida aperta (SBA) is one of the most common congenital malformations. It can cause severe lifelong physical and neurodevelopmental disabilities. Experimental and clinical studies have shown that the neurological deficits associated with SBA are not simply caused by incomplete neurulation at the level of the lesion. Additional damage is caused by prolonged exposure of the spinal cord and nerves to the intrauterine environment and a suction gradient due to cerebrospinal fluid leakage, leading to progressive downward displacement of the hindbrain. This natural history can be reversed by prenatal repair. A randomised controlled trial demonstrated that mid-gestational maternal-fetal surgery for SBA decreases the need for ventriculoperitoneal shunting and hindbrain herniation at 12 months and improves neurological motor function at 30 months of age. This came at the price of maternal and fetal risks, the most relevant ones being increased prematurity and a persistent uterine corporeal scar. Recently minimally invasive fetal approaches have been introduced clinically yet they lack extensive experimental or clinical trials. We aim to provide clinicians with the essential information necessary to counsel SBA parents as the basis for considering referral of selected patients to expert fetal surgery centres. We review the reported clinical outcomes and discuss recent developments of potentially less invasive fetal SBA approaches.

Fetoscopic two-layer closure of open neural tube defects

OBJECTIVE

Fetoscopy for closure of open neural tube defects (NTD) remains controversial, as the use of patches or single-layer closure is not considered to meet the standards of good neurosurgical reconstruction. In this study, we describe a fetoscopic two-layer (myofascial and skin) closure technique for the treatment of NTD in five patients and report the preliminary anatomical outcome at birth.

METHODS

From February to September 2017, five pregnant women with a fetus with a NTD, including three cases of myelomeningocele and two cases of myelocele, were operated on using a fetoscopic two-layer closure technique. In this technique, with the uterus exteriorized and using three 10-Fr ports, the placode is dissected from the surrounding tissue and detethered, removing the cystic tissue. The skin is undermined by blunt dissection and the defect is sutured to the midline in two layers (myofascial and skin) using a running 4/0 resorbable barbed suture.

RESULTS

Median gestational age at the procedure was 24 + 3 (range, 23 + 5 to 27 + 3) weeks. Surgery was successful in all cases, without any intraoperative complications. Median time in surgery was 180 (range, 140-180) min and median time for fetoscopy was 105 (range, 65-120) min. In terms of obstetric complications, three cases of premature rupture of membranes and one case of chorioamnionitis were recorded. Median gestational age at delivery was 34 + 1 (range, 25 + 4 to 37 + 2) weeks and two patients delivered vaginally. The closed defect was watertight with good quality tissue in all cases.

CONCLUSION

Fetoscopic two-layer closure of NTD may improve the quality of the tissue covering the defect, diminishing the need for postnatal surgical revision, and preserving the well-documented beneficial effects of prenatal closure on the neural tissue and hindbrain herniation. However, this technique may not be appropriate for those cases with wide diastasis of the myofascial layer or with a low quantity of available tissue. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Spinal Imaging Findings of Open Spinal Dysraphisms on Fetal and Postnatal MRI

BACKGROUND AND PURPOSE

Fetal MRI has become a valuable tool in the evaluation of open spinal dysraphisms making studies comparing prenatal and postnatal MRI findings increasingly important. Our aim was to determine the accuracy of predicting the level of the spinal dysraphic defect of open spinal dysraphisms on fetal MR imaging and to report additional findings observed when comparing fetal and postnatal MR imaging of the spine in this population.

MATERIALS AND METHODS

A single-center retrospective analysis was performed of fetal MRIs with open spinal dysraphisms from 2004 through 2016 with available diagnostic postnatal spine MR imaging. Images were reviewed by 2 board-certified fellowship-trained pediatric neuroradiologists. Corresponding clinical/operative reports were reviewed.

RESULTS

One hundred nineteen fetal MRIs of open spinal dysraphisms were included. The level of the osseous defect between fetal and postnatal MR imaging was concordant in 42.9% (51/119) of cases and was 1 level different in 39% (47/119) of cases. On postnatal MR imaging, type II split cord malformation was seen in 8.4% (10/119) of cases, with only 50% (5/10) of these cases identified prospectively on fetal MR imaging. Syrinx was noted in 3% (4/119) of prenatal studies, all cervical, all confirmed on postnatal MR imaging.

CONCLUSIONS

Fetal MR imaging is accurate in detecting the level of the spinal dysraphic defect, which has an impact on prenatal counseling, neurologic outcomes, and eligibility for fetal surgery. In addition, fetal MR imaging is limited in its ability to detect split cord malformations in patients with open spinal dysraphisms. Although rare, fetal MR imaging has a high specificity for detection of cervical spinal cord syrinx.

Using poly(l-lactic acid) and poly(ɛ-caprolactone) blends to fabricate self-expanding, watertight and biodegradable surgical patches for potential fetoscopic myelomeningocele repair

Our study focuses on the development and characterization of a self-expanding, watertight and biodegradable patch for fetoscopic myelomeningocele (MMC) prenatal repair. We fabricated poly(l-lactic acid) (PLA) and poly(ɛ-caprolactone) (PCL) blend films by solution casting. Formulation c with average glass transition temperature of 37.6 ± 1.2°C was chosen for temporospatial recovery. Favorable results from surface studies reflected homogeneous dispersion of polymers in the blend. The cytotoxicity was studied in human foreskin fibroblasts. The blend film was cytocompatible, evidenced by matching percentage of live cells in exposed and control solutions. Subsequently, liquid water permeability experiments confirmed watertight nature of films. Finally, in vitro degradation was investigated in phosphate buffered saline (PBS) and amniotic fluid (AF) separately for 16 weeks. Similar weight loss (n = 6, p = 0.912) and significantly different (n = 3, p = 0.025) surface roughness was observed in PBS and AF, respectively, at 16 weeks. Functional group analysis displayed increasing carbonyl and hydroxyl bonds in PBS and AF, respectively, over time, indicating progression of hydrolytic degradation. Favorable characterization results provide strong evidence to employ PLA-PCL blend films as surgical patches in fetoscopic MMC repair. Designed patch serves as standalone system to successfully tackle impending hurdles of MMC repair and proves to be a superior alternative compared to existing patches. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 107B: 295-305, 2019.

Safety and efficacy of fetal surgery techniques to close a spina bifida defect in the fetal lamb model: A systematic review

OBJECTIVE

To determine the safety and efficacy of different neurosurgical techniques for closure of spina bifida (SB) in the fetal lamb model.

METHOD

Systematic review of studies reporting on fetal lambs undergoing induction and closure of SB compared with non-operated normal lambs (negative controls) and/or lambs not undergoing closure of the defect (positive controls). Primary outcomes were (1) survival at birth (safety) and/or (2) presence of Somatosensory Evoked Potentials on hind limbs and/or improvement in quantitative histological spinal cord findings and/or reversal of hindbrain herniation (efficacy).

RESULTS

Out of 1311, 36 full-text articles were eligible. Nineteen were included for quality assessment. Due to high bias, only 2 adequately powered studies were included in the final analysis. An open approach using a 2-layer closure (muscle flap or acellular-dermal-matrix patch plus skin) was the only safe (patch + skin) and effective (both techniques) technique for prenatal closure in this animal model. No comparable level of evidence was identified for other techniques.

CONCLUSION

The experimental literature on prenatal SB closure underscores the lack of standardization. At present, there is animal experimental evidence that a 2-layer closure by hysterotomy is safe and effective. This technique is currently clinically used in a subset of patients. As new clinical techniques are introduced, it would seem logic to preclinically validate them against this experimental standard.