491: Long term infant outcomes of prenatally suspected septo-optic dysplasia

Abstract

Septo-optic dysplasia (SOD) is characterized by at least 2 of 3 findings: optic nerve hypoplasia, absent cavum septi pellucidi (CSP) and hypothalamic-pituitary dysfunction. Prenatally, the condition is suspected based on an absent CSP, but the final diagnosis can only be made postnatally, when pituitary function and opthalmological assessments are performed. The aim of our study was to describe the long-term outcome of fetuses suspected prenatally to have SOD. Retrospective cohort study of all fetuses identified with an absent CSP, but no other major structural abnormalities, in a single tertiary medical center between 1/1/2008 and 31/8/2019. Pregnancy and delivery outcomes were retrieved. For liveborn babies neuroimaging, ophthalmologic, endocrine and developmental evaluations were assessed for SOD confirmation. In cases of pregnancy termination autopsies were reviewed. Of 219 fetuses with absent CSP, 104 had fused anterior horns of the lateral ventricles and forniceal columns. Of these, 23 had suspected SOD on fetal ultrasound and MRI. Five cases underwent pregnancy termination and one case was complicated by peri-viable PPROM and stillbirth. Complete postnatal follow up was available for 13 cases with an average follow up period of 9.7 years. Five children (20.8% of all prenatally suspected SOD) had a confirmed diagnosis of SOD. Neuroimaging findings included septal remnants, fused forniceal columns, dysplastic temporal horns, diffusely thinned corpus callosum and normal olfactory tracts and bulbs. Developmental delay was present in three children. Of the remaining 8 children with an isolated absent CSP, 2 had motor and/or speech delays. In 6 cases where autopsy was available, disruption of the septal leaflets, but normal pituitary and optic nerves, were noted, precluding the diagnosis of SOD. A minority of all cases of absent CSP are confirmed SOD. Establishing this diagnosis requires multidisciplinary long term follow up. Counseling remains challenging as the condition can only be confirmed postnatally and clinical presentation is variable.