Myelomeningocele (MMC) causes significant brain microstructure changes, often leading to impaired long-term neurodevelopmental outcomes. Diffusion-Weighted Imaging (DWI), a magnetic resonance imaging (MRI) technique, provides objective metrics like Apparent Diffusion Coefficient (ADC) values, characterizing the fetal brain microstructure. This new study aimed to compare prenatal brain ADC values, obtained after prenatal MMC repair, between infants with normal and impaired neurodevelopmental outcomes at or after 18 months of age. Specifically, the researchers measured Fetal Brain ADC values in multiple brain regions, including white matter, basal ganglia, pons, and the cerebellum.
Fetal Brain ADC Findings and Neurodevelopmental Outcome
This retrospective study analysed data from children who received prenatal MMC repair, using either fetoscopic or open-hysterotomy approaches, between 2012 and 2022. Investigators performed a 1.5-Tesla MRI-DWI scan of the fetal brain approximately six weeks following the surgery. A developmental paediatrician evaluated neurodevelopmental status using several tools, including the Capute Scales, the gross motor domain of the Revised Gesell Developmental Schedules, and the Developmental Profile-3 (DP-3) test. Researchers calculated developmental quotients, and a score below 85 defined an impaired outcome. Fetal Brain ADC measurements differed significantly between the two outcome groups.
Clinical Implications for Prenatal Myelomeningocele Repair
The findings indicate a strong association between specific fetal brain ADC values and postnatal neurodevelopmental results. Consequently, ADC values could serve as a non-invasive, objective biomarker for prognosticating long-term neurodevelopment. Therefore, physicians gain a powerful tool for pre- and post-operative counselling with families electing prenatal MMC repair. Furthermore, this imaging marker could help stratify patients for targeted post-natal therapies and surveillance protocols, especially for those at high risk of impairment. Notably, the benefits of prenatal MMC repair include reduced rates of ventriculoperitoneal shunting and improved motor function, yet risks like preterm birth remain crucial considerations. Developing countries like India show a high prevalence of MMC, making the adoption of advanced diagnostics like DWI highly relevant for established fetal therapy centres in the region.
Frequently Asked Questions
Q1: What is the significance of Fetal Brain ADC values in Myelomeningocele (MMC)?
Apparent Diffusion Coefficient (ADC) values are quantitative metrics from MRI-DWI that characterise the microstructure of the fetal brain. In myelomeningocele patients, these values can indicate subtle alterations in the brain and act as an objective biomarker to predict the child’s long-term neurodevelopmental outcome after prenatal repair.
Q2: Which developmental tests did the study use to assess the children?
The study used a battery of tests to assess neurodevelopmental outcome at or after 18 months of age. These included the Capute Scales (Clinical Adaptive Test and Clinical Linguistic and Auditory Milestone Scale), the gross motor domain of the Revised Gesell Developmental Schedules, and the Developmental Profile-3 (DP-3).
Q3: What defined an impaired neurodevelopmental outcome in this study?
An impaired neurodevelopmental outcome was defined as a Developmental Quotient score below 85 in any of the assessed domains (Capute Scales, gross motor, or DP-3 test) at the time of the follow-up assessment (≥18 months of age).
References
- Corroenne R et al. Association between fetal brain diffusion-weighted imaging and postnatal neurodevelopmental outcome after prenatal myelomeningocele repair. Ultrasound Obstet Gynecol. 2026 Jan 25. doi: 10.1002/uog.70170. PMID: 41581239.
- M Das, N S, V Jain. Fetal in-utero management of myelomeningocele: a mini-review on history, challenges, management gap, and recommendations. NIH. 2024.
- Establishing Prenatal Surgery for Myelomeningocele in Asia: The Singapore Consensus. Fetal Diagnosis and Therapy. 2017.
- J Jeyabalan et al. Diffusion tensor imaging in children following prenatal myelomeningocele repair and its predictive value for the need and timing of subsequent CSF diversion surgery for hydrocephalus. PubMed. 2021.