The "Swiss Pre- to Postnatal Neurodevelopmental Cohort": A multimodal longitudinal resource bridging brain development, cognitive and socio-emotional outcomes, and genotype

The study of prenatal human brain development has long been limited by the practical and technical difficulties associated with foetal imaging (Weiss et al., 2024). Recent methodological advances, including improved foetal MRI acquisition and deep learning-based motion correction and image reconstruction (Hart et al., 2020; Xu et al., 2023), have enabled the prenatal characterisation of precise structural brain features including precise brain segmentation (Grifell I Plana et al., 2026; Zalevskyi et al., 2026). Nevertheless, longitudinal studies linking these early prenatal brain characteristics to postnatal neurodevelopmental outcomes remain scarce. Bridging this gap holds considerable promise for the early identification of neurodevelopmental risk and guiding early intervention. In this context, the Swiss Pre- to Postnatal Neurodevelopmental Cohort was established to provide, for the first time, openly accessible longitudinal multimodal data, spanning foetal life through childhood, integrating advanced neuroimaging, cognitive, socio-emotional, and genetic measures both in children with congenital malformations of the corpus callosum, also referred to callosal dysgenesis, as well as in children with typical brain development.

Such a longitudinal multimodal cohort is highly valuable in developing populations as it offers a convergence of clinical and scientific relevance, with a multifaceted impact on advancing knowledge and improving outcomes for vulnerable children and their families. In children with callosal dysgenesis, its clinical relevance resides in its applicability to real-world healthcare settings. In Switzerland, the diagnosis of callosal dysgenesis is made prenatally by ultra-sound around 20 gestational weeks. The prognosis for these children in terms of cognitive and socio-emotional functioning is still unclear, and clinicians are crucially lacking evidence to guide these families. Identifying pre-natal neurological signatures of cognitive functioning are much needed in order for clinicians to provide families with an accurate prognosis for their child diagnosed with callosal dysgenesis. In typically developing children, this approach also holds considerable value, as it could reveal associations between foetal brain characteristics and later neurodevelopmental vulnerability, such as autism spectrum disorder. From a scientific standpoint, this cohort offers a unique opportunity to address fundamental questions about trajectories of neurodevelopmental heterogeneity. This challenge is particularly pronounced in callosal dysgenesis, where the factors underlying the wide spectrum of cognitive outcomes, ranging from asymptomatic presentation to marked difficulties, remain to be comprehensively characterised. Examining both populations within a unified longitudinal framework also provides a unique window into neuroplasticity and compensatory brain mechanisms across typical and atypical brain development (Paul et al., 2007). Furthermore, this cohort has the potential to advance our understanding of the specific role of the corpus callosum and interhemispheric communication during neurodevelopment (Freitag et al., 2009; Hutchinson et al., 2008; Postema et al., 2019).

In this working report, we described the ongoing Swiss Pre- to Postnatal Neurodevelopmental Cohort, which will ultimately be released as an open-access multimodal dataset to deepen our understanding of pre- to postnatal brain development, its cognitive and socio-emotional consequences in children, and its genetic underpinnings.

Key defining features of this cohort include:

·       Longitudinal design spanning the prenatal to postnatal period, with brain MRI acquired both in utero and at school age

·       Comprehensive cognitive and socio-emotional assessment at school age

·       Multimodal neuroimaging at school age, encompassing anatomical MRI, resting-state functional MRI, diffusion MRI, resting-state apparent diffusion coefficient (ADC) functional MRI, and quantitative susceptibility mapping (QSM)

·       Genome-wide genotyping enabling the investigation of genetic influences on brain and neurodevelopmental outcomes