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. 2025 Jan 24;122(2):33–37. doi: 10.3238/arztebl.m2024.0239

The Intrauterine Treatment of Open Spinal Dysraphism

Corinna Keil 1,*, Benjamin Sass 2, Maximilian Schulze 3, Siegmund Köhler 1, Roland Axt-Fliedner 4, Ivonne Bedei 4
PMCID: PMC12416013  PMID: 39654393

Abstract

Background

Open spinal dysraphism is a congenital malformation that causes major morbidity. Its consequences include sensory and motor impairment as well as bladder- and bowel dysfunction. It is often also associated with prenatal ventriculomegaly, which, in turn, necessitates postnatal treatment with a ventriculoperitoneal shunt in approximately 80% of cases. Prenatal therapy with coverage of neural tube defect can reduce the shunt rate and preserve motor function. In this review, we describe the different surgical procedures and their outcomes.

Methods

This review is based on publications that were retrieved by a selective literature search in the MEDLINE, Web of Science, EMBASE, Scopus, and Cochrane databases, employing pertinent keywords. Studies of all types (except case reports) that were published in English or German in the period 2010–2024 were included.

Results

The randomized, controlled MOMS trial showed that intrauterine surgery for defect closure resulted in less progressive neural tissue damage than postnatal surgery and reduced the need for shunting by approximately half (40% vs. 82%). Since the publication of these results, various prenatal surgical procedures have been established, including hysterotomy-assisted, percutaneous fetoscopic, and laparotomy-assisted fetoscopic closure. The individual surgical methods yield comparable results in terms of motor function and shunt rate. A problem with these procedures is that they increase the likelihood of preterm birth, to an extent that varies from one type of procedure to another.

Conclusion

Prenatal surgery improves motor function and reduces the shunt rate but long-term outcomes beyond adolescence are still lacking. Transparent and interdisciplinary counseling is essential in prenatal communication to inform parents not only about the potential benefits of this treatment, but also about its limitations and risks.

Information on this CME

This article has been certified by the North Rhine Academy for Continuing Medical Education.The questions on this article may be found at http://daebl.de/RY95. The closing date for entries is 23 January 2026. Participation is possible at cme.aerzteblatt.de

Spinal dysraphism is a severe, rarely fatal, congenital malformation affecting the central nervous system. This neural tube defect is of multifactorial etiology and results from a disturbance of primary or secondary neurulation. Apart from folic acid deficiency, genetic and epigenetic factors play a role; other factors include poorly controlled diabetes mellitus prior to conception, maternal obesity and anticonvulsants (valproic acid) (1). The overall prevalence is approximately 8/10 000 births in Europe, with a live birth rate of 2/10 000. Over the past decades, it has largely remained unchanged and the European rate can be applied to Germany (1, 2).

A distinction is made between isolated and associated neural tube defects. Associated neural tube defects occur with various syndromal and/or genetic disorders, such as trisomy 18/13, CHARGE syndrome and VACTERL association. Furthermore, clefts, cardiac malformations as well as skeletal and renal malformations can occur in this context and have a significant impact on the prognosis of affected children (3, 4).

Neural tube defects can be open or closed. A characteristic feature of open lesions (formerly spina bifida aperta, SBA) is that the nervous tissue is in contact with the intrauterine environment, while closed lesions (formerly spina bifida occulta) are covered by soft tissue and/or skin.

The most common form of open defects is the cystic variant, the myelomeningocele (MMC). With this anomaly, neural tissue (so-called placode) and meninges protrude from the spinal canal. To be distinguished from MMC are flat defects where the placode is at skin level (myeloschisis) (1).

Open neural tube defects are typically associated with a Chiari II malformation where the posterior fossa is too small, resulting in displacement of the cerebellum through the foramen magnum into the cervical spine (so-called hindbrain herniation, HBH), which, in turn, impairs the circulation and absorption of cerebrospinal fluid (CSF) (5).

According to the two-hit hypothesis, the pathogenesis of open spinal dysraphism is as follows: The first ‘hit’ results from the failure of closure of the neural tube and vertebrae during post–conception days 22–28. The direct exposure of the neural structures to the intrauterine environment leads to degeneration, inflammation, and mechanical injury—this represents the second ‘hit’. According to histopathological studies, damage to the exposed spinal cord starts already prior to a gestational age (GA) of 16 weeks and leads to progressive loss of motor neurons. Depending on the location and extent of the injury, this results in sensory and motor impairment of the affected muscle groups, potentially to the point of paraplegia.

The Chiari II malformation can be associated with ventriculomegaly or hydrocephalus, necessitating the implantation of a ventriculoperitoneal shunt (VP shunt) (6, 7).

Other associated complications include disorders of bladder, bowel and sexual function, as well as orthopedic problems (foot deformities, hip dysplasia and kyphosis) (1). If left untreated, infections (meningitis, ventriculitis) or brainstem compression will lead to a fatal outcome. Prenatal or postnatal surgical repair of the defect is therefore crucial. In this review, we provide an insight into the currently available evidence on the prenatal treatment of open spinal dysraphism. This review is based on publications that were retrieved by a selective literature search in the MEDLINE, Web of Science, EMBASE, Scopus, and Cochrane databases, employing pertinent keywords according to the PICO framework (patient, intervention, comparison, outcome). Studies of all types (except case reports) that were published in English or German in the period 2010–2024 were included. The keywords “spina bifida“, “fetal therapy“ and “feto-maternal outcome“ were used.

The diagnosis of open spinal dysraphism

Ultrasound examinations are an integral part of prenatal care, supplemented by fetal magnetic resonance imaging (8). A detailed diagnostic evaluation is essential when preparing for intrauterine therapy (9).

Ultrasound

Characteristic changes are noted at the time of the second antenatal screening visit set by the German Maternity Guidelines between a GA of 18 and 22 weeks; however, first signs may already be visualized in the first trimester. In cross-sectional planes, the fetal head has a small biparietal diameter (BPD) and a characteristic shape (“lemon sign”). The changes of the posterior cranial fossa result in caudal displacement of the cerebellum (“banana sign”). Ventriculomegaly with enlargement of the lateral ventricles may already be noted (10). In the detailed sonographic scan of the spine, the first affected vertebra defines the anatomical level; other aspects described include the position of the vertebral arches and the morphology of the lesion (MMC or myeloschisis) (10, 11).

In order to determine the motor level of the lesion, an ultrasound assessment of fetal movements of the lower limbs is performed and the findings are matched to the individual neurotomes and muscle groups. The motor outcome correlates significantly better with this functional description than does the anatomical level (12). The classification of the findings, especially the distinction between isolated and associated neural tube defects, is crucial for prognostication (13, 14).

Human genetic testing

In addition to diagnostic imaging, fetal karyotyping should be performed, at least if prenatal surgery is considered. Overall, the rate of genetic abnormalities is low in fetuses with isolated neural tube defect; in the case of associated suspicious findings, it is 16% to 25% (4, 15).

Interdisciplinary counseling

Given the broad spectrum of conditions, interdisciplinary counseling of parents (neuropediatrics, neurosurgery, prenatal diagnostics) plays a decisive role. Counseling should be realistic, open-ended and non-directive, providing a clear picture of open spinal dysraphism as a chronic disease with varying degrees of severity. It also needs to include a discussion on pre- or postnatal surgery and termination of pregnancy.

Referral to self-help groups as well as psychosocial support offerings must be an integral part of the discussions (9).

In Germany, a termination of pregnancy is performed in 46% to 86% of cases (4, 16). However, these rates are based on data from individual centers, since structured registries responsible for comprehensive data collection do not exist. Worldwide, a termination of pregnancy is performed in 63% of cases (range 31–97%) (15).

Postnatal surgical treatment

Until the introduction of prenatal therapy, postnatal neurosurgery was the only treatment available and it has remained an important option for some cases even until today.

In addition to restoring normal circulation of cerebrospinal fluid in the area of the malformed spinal cord, postpartum surgery is performed to create a barrier between neural structures and the environment to prevent infectious complications. During the postnatal surgical procedure, residual arachnoid, epidermal and dermal structures are removed, the filum terminale is dissected and a so-called tubularization is performed where the natural folding of the spinal card is surgically recreated in the area of the placode (17).

Long-term observational studies on 117 patients with significant Chiari II malformation, who underwent postnatal surgery, found a high mortality rate of 35% (18). More than 80% of the pediatric patients undergoing postpartum surgery require the placement of a shunt to lessen this severe disease course as well as neurological and intellectual impairments. Of these, 46% have to undergo shunt revision during their first year (5).

In order to prevent infection (meningitis, ventriculitis), the surgical procedure is frequently performed within 48 hours postpartum; however, there is no clear evidence to date to support a better outcome as a result of this approach (19). The “watertight closure” of the infant’s back is absolutely necessary to ensure that cerebellar herniation, CSF circulation impairment and brainstem compression subside (17).

The tethered cord syndrome (TCS) is a well-recognized long-term complication. It is characterized adhesions between neural structures and the surrounding tissue. During the normal growth in length and the associated ascending of the spinal cord in the spinal canal, TCS can result in neurological deficits (motor, sensory) in the lower limbs, back pain or leg pain, scoliosis, and incontinence. Patients with TCS account for 2.8% to 32% of operated patients (17, 20).

Prenatal therapy of open spinal dysraphism

The approach of intrauterine therapy is based on the hypothesis that an early closure of the defect reduces the complications of the second hit. The only randomized trial, the MOMS trial, compared prenatal with postnatal surgery. The results showed a reduction in the postnatal shunt rate as well as improvements in motor function after prenatal therapy. However, an increase in fetomaternal complications was also noted (eTable A) (21, 22).

eTable A. The MOMS trial: child outcome parameters and maternal risks (Adzick et al. 2011 [23]).

Outcome parameters and risks Prenatal Postnatal RR [95% CI] p-value
n 78 80
Child outcome parameters n (%)
Ventriculoperitoneal shunt by the age of 12 months 31 (40) 66 (82) 0.48 [0.36; 0.64] p<0.001
Improvement in hindbrain herniation by 12 months 45 (64) 66 (96) p<0.001
Independent ambulation by 30 months 39 (44.8) 21 (23.9) p = 0.01
Fetal/neonatal death 2 (3) 2 (2) 1.03 [0.14; 7.10] p =1.0
Spontaneous preterm birth 30 (38) 11 (14) 2.8 [1.51; 5.18] p<0.001
Premature membrane rupture 40 (44) 7 (7.6) 6.15 [2.75; 13.78] p<0.001
Postoperative amniotic fluid leakage NS
Mean GA at birth 34.1 ± 3.1 37.3 ± 1.1 p<0.001
 Birth at GA <30 weeks 10 (13) 0 (0)
 Birth at GA 30–34 weeks 26 (33) 4 (5)
 Birth at GA 35–36 weeks 26 (33) 8 (10)
 Birth at GA >37 weeks 16 (21) 68 (85)
Acute neonatal respiratory distress syndrome 16 (21) 5 (6) p = 0.008
Postnatal surgical revision of the child’s back NS
Maternal risks n (%) 78 80
Maternal deaths 0 0
Premature placental abruption 6 (6.6) 0 p<0.0001
Uterine rupture NS
Hysterotomy wound dehiscence (mild-severe) 31 (35.3) 0 p<0.0001
Amnion separation 30 (33) 0 p<0.0001
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CI, confidence interval; GA, gestational age; MOMS, Management of Myelomeningocele; NS, not stated

The surgical procedure is usually performed between 19–26 weeks’ gestation. The inclusion and exclusion criteria were prepared on the basis of the MOMS trial and later modified (eBox) (1). The costs of prenatal surgery are covered by German health insurances.

eBox. Inclusion and exclusion criteria for the intrauterine treatment of open spinal dysraphism, as per the eTable.

  • Inclusion criteria

    • Age of patient ≥ 18 years

    • Informed consent

    • Location of the defect between T1 – S1

    • Hindbrain herniation (HBH), confirmed by ultrasound and magnetic resonance imaging

    • Gestational age between 19 + 0 – 26 + 1 weeks at the time of surgery

    • Normal fetal karyotype

  • Exclusion criteria

    • Multiple pregnancy

    • Poorly controlled pre-existing insulin-dependent diabetes mellitus

    • Malformations not associated with open spinal dysraphism

    • Kyphosis ≥ 30°

    • Placed/planned cerclage/ total closure of the cervix

    • Status post spontaneous birth <37 + 0 GA in singleton pregnancy

    • Cervical length <25 mm

    • Placenta previa, history of premature placental abruption

    • Rhesus or Kell sensitization, status post neonatal alloimmune thrombocytopenia (NAIT)

    • Maternal hepatitis B + C, or HIV infection

    • Maternal obesity (BMI ≥ 40)

    • Maternal hypertension (uncontrollable or chronic with end organ damage)

    • Uterine malformations or large/multiple uterine fibroids

    • Maternal contraindications, such as extensive fibroid enucleation, previous fetal surgery

    • A sufficiently supportive social environment

    • Problems attending follow-up appointments at the center

    • Participation in another intervention study that may impact maternal or fetal morbidity or mortality

At present, there are various surgical methods that differ from each other with regard to access and defect closure; these have been modified over time. In addition to the MOMS trial, the available data is drawn from numerous case series of various centers.

Hysterotomy-assisted repair

Surgical access is via a lower abdominal transverse laparotomy with subsequent hysterotomy and repair of the fetal neural tube defect in a manner similar to the postnatal procedure (Figure 1, Figure 4).

Figure 1.

Figure 1

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Hysterotomy-assisted repair

Uterus with hysterotomy (*) and retaining sutures placed; during surgery, the amniotic fluid is replaced via the inserted tube. The photo shows the fetal back after completed hysterotomy-assisted repair of the fetal myelomeningocele (arrow).

By courtesy of Prof. Ueli Moehrlen,

University Children‘s Hospital Zurich, Switzerland

Figure 4.

Figure 4

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Schematic representation of three different surgical methods for prenatal treatment of fetal open spinal dysraphism, from top to bottom: Hysterotomy-assisted repair involves lower abdominal transverse laparotomy with subsequent hysterotomy and multi-layer repair of the fetal back, similar to the postnatal surgical repair procedure. Laparotomy-assisted fetoscopic repair (hybrid method) combines lower abdominal transverse laparotomy with subsequent externalization of the uterus. Prior to placement of the fetoscopic ports, the amnion is fixed with sutures; the defect repair is performed in three layers (Durapatch, muscle, skin). Percutaneous fetoscopic repair is performed without laparotomy. The repair of the defect is performed using a single-layer patch for coverage or by multi-layer repair, depending on surgical preference.

created with Biorender

This surgical procedure was established in the only available randomized clinical trial, the MOMS trial. A total of 183 women were randomized into two groups (antenatal [n = 78] and postnatal [n = 80] surgery). The results showed an advantage of prenatal therapy with a reduction in the postnatal shunt rate (antenatal 31 (40%), postnatal 66 (82%), RR [95% confidence interval] 0.48 [0.36; 0.64]; p<0.001) as well as a decrease in hindbrain herniation and an improvement in motor function. Furthermore, 42% of children who underwent prenatal surgery were able to walk independently by 30 months compared to 21% of children treated with postnatal surgery (p = 0.001); in each of the two groups occurred 2 perinatal deaths. One problem was the rate of premature births (GA of 34.1 versus 37.3 weeks; p ≤ 0.001), another the rate of maternal complications (eTable A) (23).

After the procedure, delivery by caesarean section is required for this and all subsequent pregnancies. The data of the MOMS trial were confirmed in various centers in the following years and the procedure was approved by the FDA. Besides a reduction in the need for shunt placement as well as improvements in motor development, a lower rate of secondary neurosurgical procedures as well as possible positive effects on bladder and bowel dysfunction were observed (20, 24–26).

The cohort analysis of the Zurich Center, including 148 cases, found a shunt rate of 37% (39/106) at the end of the first year of life. 84% (48/57) of the children who underwent prenatal surgery were able to walk by the age of three years. In only 0.7% (1/106) of cases, no watertight closure of the back was achieved. Perinatal mortality was 0.7% (1/148) with no maternal mortality (27). A systematic analysis of the fetomaternal complication rate by the same working group found a higher birth rate GA >37 weeks (52/145; 36%) compared to MOMS (16/78; 21%) and a lower amnion separation rate. The rates of premature rupture of membranes and placental abruption were comparable (eTable B) (28).

eTable B. Child outcome parameters and maternal risks in hysterotomy-assisted repair (27, 28) and laparotomy-assisted fetoscopic repair (hybrid) (35, 36).

Outcome parameters and risks Hysterotomy-assisted repair Laparotomy-assisted fetoscopic repair (hybrid)
Moehrlen et al. 2021 (27);
Vonzun et al. 2020* (28) 		Sanz Cortes et al. 2024 (35),
Krispin et al. 2023* (36)
n 148 total cohort, 145 born, 106 = 12 months, 57 = 3 years 102 total cohort, 95 born; 80 = 12 months; 73 = 30 months
Child outcome parameters n (%)
Ventriculoperitoneal shunt by the age of 12 months 39/106 (37) 29/80 (36.3)
Improvement in hindbrain herniation by 12 months 119/132 (90) 52/54 (96.3)
Independent ambulation by 30 months 48/57 (84) 38/73 (52.1)
Fetal/neonatal death 2/148 (1.4) 0/102 (0)
Spontaneous preterm birth NS NS
Premature membrane rupture 42/124 (33.6) 29/102 (28.4)
Postoperative amniotic fluid leakage 7/124 (5.6)* NA
Mean GA at birth NS 38.1
 Birth at GA <28 weeks 2/145 (1) 4/95 (4.2)
 Birth at GA 28 + 0–31 + 6 weeks 9/145 (6) 8/95 (8.4)
 Birth at GA 32 + 0–33 + 6 weeks 20/145 (13) 4/95 (4.2)
 Birth at GA 28 + 0–36 + 6 weeks 62/145 (43) 21/95 (22.1)
 Birth at GA > 37 weeks 52/145 (36) 58/95 (61.1)
Acute neonatal respiratory distress syndrome 8/145 (5.5)
Postnatal surgical revision of the child’s back 1/145 (0.7) 12/73 (16.4)
Maternal risks n (%) 124* 102*
Maternal deaths 0 /124 (0) 0/102 (0)
Premature placental abruption 11/124 (8.8) 2/102 (2.0)
Uterine rupture 1/124 (0.8) 0/102 (0)
Hysterotomy wound dehiscence (mild-severe) NS 0/102 (0)
Amnion separation 20/124 (16) 41/102 (40.2)
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GA, gestational age; NS, not stated

Fetoscopic techniques

Fetoscopic techniques were developed with the goal to minimize the fetomaternal risks associated with hysterotomy-assisted repair while achieving equivalent outcomes in terms of shunt rate and motor function. The two principal techniques are explained below.

Percutaneous fetoscopic repair

This technique employs a strictly percutaneous, fetoscopic approach, with repair of the fetal back using a single or double-layer patch technique depending on surgical preference (Figure 2, Figure 4) (29, 30).

Figure 2.

Figure 2

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Percutaneous fetoscopic repair

Maternal abdominal wall with trocars inserted (arrow)

By courtesy of Prof. Cleisson F.A. Peralta,

The Heart Hospital, Sao Paulo, Brazil

For the fetal long-term outcome with regard to the need for shunt placement as well as motor development, the data obtained were similar to that of the MOMS trial: In the German cohort (n = 71), 32/71 (45%) needed a VP shunt by 12 months; 32/54 (84%) were able to walk by age 30 months. After 30 months, 35/50 (70%) demonstrated normal psychomotor and mental development (31). A multicenter analysis by Lapa et al. produced similar data. In their analysis, 42/103 (40.8%) required a VP shunt by the age of 12 months and 84/103 (81.6%) had learnt to walk by the age of 30 months (30). Both groups demonstrated a low maternal risk without maternal mortality. After this surgical procedure, cesarean section was the mode of delivery for the majority of cases (88–100%) (21).

An increased rate of premature rupture of membranes (43/51; 84%) with associated preterm birth was observed; furthermore, postnatal revision surgery on the fetal back was required in 9.7–28% of cases because no watertight closure had been achieved (eTable C) (30–33).

eTable C. Child outcome parameters and maternal risks in percutaneous laparoscopic repair.

Outcome parameters and risks Lapa et al. 2021 (30);
Verweij et al. 2021*1 (21) 		Graf et al 2016 (33),
Degenhardt et al 2014*1 (32),
Diehl et al 2021*2 (31)
n Total cohort 116,
103 = 12 months, 59 = 30 months
[95% CI]		 Total cohort 71,
52 = 30 months*2
[95% CI]
Child outcome parameters n (%)
Ventriculoperitoneal shunt by the age of 12 months 48/103(46.6) 32/71 (45)
Improvement in hindbrain herniation by 12 months 84/103 (81.6) NA
Independent ambulation by 30 months 32/ 59 (54.2) 32/54 (84)*2
Fetal/neonatal death 4/116 (3.4) 5/71 (7)
Spontaneous preterm birth NS NS
Premature membrane rupture (67)* NS
Postoperative amniotic fluid leakage NS 43/51 (84.3)
Mean GA at birth 32.5 [30.9; 35.2]*1 Mean GA at birth 32.2 [24.3; 38.3]
 Birth at GA <32 weeks 34/103 (33.0) Birth at GA <30 weeks 9/71 (13)
Birth at GA 30–34 weeks 45/71 (63)
Birth at GA 35–36 weeks 9/71 (13)
Birth at GA >37 weeks 8/71 (11)
Acute neonatal respiratory distress syndrome NS NS
Postnatal surgical revision of the child’s back 10/103 (9.7) 20/71 (28)
Maternal risks n (%)
Maternal deaths 0/51*1
Premature placental abruption 0/51*1
Uterine rupture NS
Hysterotomy wound dehiscence (mild-severe) 0/51*1
Amnion separation 2/51 (4)*1
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GA, gestational age; NS, not stated

Laparotomy-assisted fetoscopic repair (“hybrid method”)

This technique combines lower abdominal transverse laparotomy with fetoscopic defect repair via 2 or 3 ports (Figure 3, Figure 4). The transverse laparotomy and subsequent externalization of the uterus allows for optimum placement of the uterine ports, independent of the position of the placenta. In addition, the amnion can be fixed in place using sutures to reduce the rate of premature rupture of membranes (Figure 3, Figure 4). The fetus itself can be manually positioned by transuterine mobilization and retained in optimum position. With the goal of achieving a watertight closure, fetoscopic repair with three layers (Durapatch, muscle and skin coverage) is performed (34).

Figure 3.

Figure 3

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Laparotomy-assisted fetoscopic repair (hybrid method). Externalized uterus after placement of 3 ports; the fetus is manually maintained in the correct position through trans-uterine manipulation.

Images from the Spina bifida Center at the University Hospital Giessen and Marburg (UKGM)

A reduction in premature births was noted, partly due to a reduced rate of premature ruptures of membranes (29/102; 28%) and a higher gestational age at birth (GA 39 weeks). 29/80 (36%) of children received a shunt within the first 12 months, while 38/73 (52.1%) were able to walk by 30 months (eTable B); this method was also approved by FDA (35, 36).

Discussion

Prenatal treatment of open spinal dysraphism demonstrates significant advantages over postnatal treatment with regard to motor function and shunt rate. However, despite these advantages, it is not a curative treatment. Some disease-specific aspects (bladder and bowel dysfunction, sexual dysfunction, secondary neurosurgical/ orthopedic procedures) are only slightly improved and neural functions that have already been lost cannot be restored. Overall, this method of treatment is still in its infancy and continually evolving as the expertise of the centers grows with increasing numbers of cases (37). Worldwide, there has been a noticeable increase in the number of centers offering this therapy, thereby making it more widely available. (38). Direct comparisons between the various surgical methods continue to pose challenges: First, open spinal dysraphism is a rare condition where different constellations of findings with a significant impact on prognosis can already be found prenatally. Furthermore, the cases operated on prenatally represent a pre-selected and heterogeneous patient population.

Time and again, there are calls for randomized controlled trials as advocated by evidence-based medicine, such as the Management of Myelomeningocele (MOMS) trial. In the field of prenatal therapy, however, there are numerous limitations to conducting randomized, controlled trials. These include long recruitment times in the face of ongoing technical advances, the fact that it is a rare condition with heterogeneous findings as well as the frequent reluctance of parents to accept randomization or to participate in a randomized, controlled trial (21).

In addition, the majority of centers are specialized in one surgical method and only few offer different surgical procedures. This makes it more difficult to conduct randomized, controlled trials. In addition, personal preferences and the technical expertise of the medical team can have an impact on randomization (38). Thus, since hardly any data from randomized, controlled trials will become available in the future, data collection and processing by the centers themselves is key. Linking prenatal and postnatal clinical courses and documenting long-term outcomes up to adulthood should be an integral part of the scientific evaluation (9).

Beyond the disease-specific aspects, the diagnosis of spinal dysraphism places a heavy psychological burden on parents and families; it appears that this negative impact is less severe if the children are treated prenatally compared to postnatal treatment. Here, motor development and family resources are predictive (39).

Attention should also be paid to the role mothers play in prenatal treatment: While surgical treatment offers no advantage to them, they bear the risk of procedure-related complications. Thus, interdisciplinary counselling of parents that addresses all aspects of the individual case is of crucial importance. While prenatal therapy can bring about significant improvements in physical independence and a reduction in associated complications, it also requires an in-depth discussion of the condition, the treatment options and the resulting risks.

In the future, advancements in surgical techniques, novel treatment approaches (for example, intrauterine stem cell therapy) and findings of basic research will contribute to a better understanding of the condition and help to optimize treatment (40).

Questions regarding the article in issue 2/2025:

The Intrauterine Treatment of Open Spinal Dysraphism

The closing date for entries is 23 January 2026. Only one answer is possible per question.

Please select the answer that is most appropriate.

Question no. 1

What overall prevalence of spinal dysraphism is reported for Europe?

  1. 0.1/10 000 live births

  2. 2/10 000 live births

  3. 12/10 000 live births

  4. 20/10 000 live births

  5. 120/10 000 live births

Question no. 2

Which of the following syndromes is not mentioned in the article as an associated factor for neural tube defects?

  1. Trisomy 18

  2. CHARGE syndrome

  3. Trisomy 21

  4. VACTERL association

  5. Trisomy 13

Question no. 3

What problem arises with open neural tube defects that are associated with a Chiari II malformation?

  1. Uncal herniation

  2. Hindbrain herniation

  3. Whole brain herniation

  4. Front brain herniation

  5. Subfalcine herniation

Question no. 4

What names are used in the article for the two characteristic signs that can be observed on ultrasound in the second trimester when examining the shape of the head and the posterior fossa?

  1. Melon sign and cucumber sign

  2. Orange sign and carrot sign

  3. Apple sign and pear sign

  4. Grape sign and squash sign

  5. Lemon sign und banana sign

Question no. 5

What percentage of children with open spinal dysraphism who underwent postnatal surgery require a shunt?

  1. Approx. 10%

  2. Approx. 20%

  3. Approx. 40%

  4. Approx. 80%

  5. Approx. 95%

Question no. 6

What is the usual timing of intrauterine surgery to treat open spinal dysraphism?

  1. Gestational age 8–11 weeks

  2. Gestational age 12–18 weeks

  3. Gestational age 19–26 weeks

  4. Gestational age 27–30 weeks

  5. Gestational age 31–35 weeks

Question no. 7

According to the article, what period is commonly chosen for postpartum surgical repair of open spinal dysraphism?

  1. Surgery within 2 hours postpartum

  2. Surgery within 48 hours postpartum

  3. Surgery within the first week of life

  4. Surgery within the first month of life

  5. Surgery within the first six months of life

Question no. 8

Which statement about prenatal treatment of open spinal dysraphism is the most appropriate?

  1. Prenatal treatment with hysterotomy-assisted repair has not yet been approved by FDA.

  2. Prenatal therapy has the advantage over postnatal therapy that already lost neural functions can be restored.

  3. Prenatal therapy has the advantage over postnatal therapy that the incidence of preterm birth is lower.

  4. Prenatal therapy has the advantage over postnatal therapy that secondary surgical procedures are no longer necessary.

  5. Prenatal therapy has advantages over postnatal therapy in respect to motor function and shunt rate; however, it is not a curative treatment either.

Question no. 9

What is the acronym of the only randomized, controlled trial to date comparing prenatal and postnatal surgery for open spinal dysraphism?

  1. SHUNT trial

  2. SPINE trial

  3. BIFIDA trial

  4. MOMS trial

  5. APERT trial

Question no. 10

According to the article, which diagnostic modality is used, besides ultrasound, to establish the diagnosis of open spinal dysraphism during pregnancy?

  1. Magnetic resonance imaging

  2. Computed tomography

  3. Fetoscopy

  4. Abdominal radiography

  5. Electromyography

Acknowledgments

Translated from the original German by Ralf Thoene, M.D.

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11. Trigo L, et al.: Am J Obstet Gynecol MFM 2023; 5: 100932.

12. Maiz N, et al.: Ultrasound Obstet Gynecol 2023; 61: 728–33.

13. Mustafa HJ, et al.: Am J Obstet Gynecol MFM 2023; 5: 100983.

14. Kunpalin Y, et al.: Prenat Diagn 2023; 43: 1605–13.

15. Johnson CY, et al.: Birth Defects Res A Clin Mol Teratol 2012; 94: 857–63.

16. Bahlmann F, et al.: Prenat Diagn 2015; 35: 228–35.

17. Caldarelli M, et al.: Springer Milan 2008; 143–55.

18. Oakeshott P, et al.: Br J Gen Pract 2003; 53: 632–6.

19. Beier AD, et al.: Neurosurgery 2019; 85: E412–3.

20. Spoor JKH, et al.: PLoS One 2023; 18: e0287175.

21. Verweij EJ, et al.: Prenat Diagn 2021; 41: 949–56.

22. Sanz Cortes M, et al.: Am J Obstet Gynecol 2021; 225: 678.e1–11.

23. Adzick NS, et al.: N Engl J Med 2011; 364: 993–1004.

24. Danzer E, et al.: Am J Obstet Gynecol 2016; 214: 269.e18.

25. Hepp ZS, et al.: Develop Med Child Neuro 2021; 63: 1302–7.

26. Mazzone L, et al.: Fetal Diagn Ther 2020; 47: 882–8.

27. Moehrlen U, et al.: Pediatr Surg Int 2021; 37: 311–6.

28. Vonzun L, et al.: BJOG 2021; 128: 1184–91.

29. Kohl T: Ultrasound Obstet Gynecol 2014; 44: 515–24.

30. Lapa DA, et al.: Ultrasound Obstet Gynecol 2021; 58: 582–9.

31. Diehl D, et al.: Ultrasound Obstet Gynecol 2021; 57: 113–8.

32. Degenhardt J, et al.: Ultrasound Obstet Gynecol 2014; 44: 525–31.

33. Graf K, et al.: Ultrasound Obstet Gynecol 2016; 47: 158–61.

34. Belfort MA, et al.: Ultrasound Obstet Gynecol 2020; 56: 532–40.

35. Sanz Cortes M, et al.: Ultrasound Obstet Gynecol 2024: 64: 203–13.

36. Krispin E, et al.: Am J Obstet Gynecol 2023; 229: 53.e1–8.

37. Joyeux L, et al.: Ultrasound Obstet Gynecol 2020; 55: 730–9.

38. Sacco A, et al.: Prenatal Diagnosis 2018; 38: 1020–7.

39. Antiel RM, et al.: Am J Obstet Gynecol 2016; 215: 522.e1–6.

40. Kunpalin Y, et al.: Prenat Diagn 2021; 41: 283–300.

Footnotes

Conflict of interest

The authors declare no conflict of interest.

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