Prenatal Sacral Anomalies Leading to the Detection of Associated Spinal Cord Malformations

Systematic analysis of the spine is recommended as part of the basic sonographic examination. The aim of our study is to assess the proportion of spinal cord anomalies diagnosed following detection of a sacral anomaly.

We analyzed retrospectively collected data in a prenatal tertiary center during a 9-year period. Patients were referred for second-line ultrasound in the context of diabetes mellitus or following detection of pelvic or lower spine anomalies. We included all cases of sacral anomalies with available postnatal or postmortem outcomes (imaging and/or pathologic data) and excluded all cases of open dysraphism (myelomeningocele).

Nineteen patients were included. The mean gestational age was 28 weeks (21-39). Sacral anomalies included 2 cases of complete agenesis, 12 cases of partial agenesis, 4 segmentation anomalies, and 1 case of abnormal angulation of the sacral spine. Fourteen associated spinal cord malformations included 8 tethered spinal cords, 5 truncated spinal cords, and 1 lipoma of the filum terminale. All anomalies were confirmed by postnatal or postmortem examinations.

Sacral anomalies detected during basic sonographic examination represent an important warning sign for associated spinal cord anomalies, with possible poor neonatal outcome.