Spinal dysraphism in newborns: Screening factors for prioritizing rapid spinal ultrasonography from a retrospective cohort study.

Background: Spinal dysraphism is a common condition and may be either open or occult. Occult dysraphism is generally diagnosed in the postnatal period through clinical examination and spinal ultrasonography (USG). Clinical signs of spinal dysraphism are common and not specific. Several spinal USG are required to confirm or exclude this condition. It is crucial to identify the infants at highest risk of dysraphism for rapid USG, and avoid unnecessary screening. The aim of the study was to evaluate the relationship between clinical examination signs and spinal USG examination results to determine which clinical signs are associated with a high risk of dysraphism, to facilitate the prioritization of infants for spinal USG examinations.

Patients and methods: We performed a retrospective cohort study in a regional neurosurgical and neonatal reference center, from January 2017 to December 2021. All infants undergoing screening for spinal dysraphism by USG during this period based on clinical indicators in the lumbosacral region were included. Infants who underwent spinal USG as part of a systematic assessment were excluded. The primary outcome was the incidence of abnormal USG results. The clinical characteristics of patients with suspected dysraphism were collected and compared between groups.

Results: We included 144 patients, 22.2 % USG results were abnormal suggesting occult dysraphism. USG was performed due to the presence of a simple sacral dimple in 41.7 % infants which was strongly associated with a normal USG result (RR = 0.32 _{95 %}CI [0.14 - 0.70]; p = 0.0029), whereas abnormal USG results were more frequent in patients with gluteal cleft abnormalities (RR = 3.09 _{95 %}CI [1.5 - 5.2]; p = 0.0029).

Conclusion: Clinical signs such as sacral dimple or gluteal cleft abnormality could help prioritizing USG. The use of a diagnostic tree based on a "step-by-step" model would make it possible to avoid some unnecessary USG and would allow comparative international studies.