Fetal agenesis of the septum pellucidum: Ultrasonic diagnosis and clinical significance.

Objective: To describe the prenatal ultrasound (US) findings, genetic results, and clinical outcomes of fetuses with suspected agenesis of the septum pellucidum (ASP) in the Chinese population.

Methods: This retrospective, single-center study included a cohort of fetuses with ASP diagnosed by prenatal imaging over a 10-year period. We evaluated US findings, associated anomalies, genetic results, and clinical outcomes. Prenatal and postnatal imaging findings were compared as well as the clinical outcome of delivery.

Results: Ninety patients were included, with a median follow-up time of 36 months (1-96 months). Thirty-six fetuses (40%) with isolated ASP were diagnosed by prenatal US or magnetic resonance imaging (MRI); 39 cases (43.3%) had ASP with central nervous system malformations and 15 cases (16.6%) had ASP with non-CNS abnormalities. Additional imaging findings were supplemented with prenatal MRI in 13 cases. Genetic tests were performed on 32 patients, of whom six had abnormalities. Prenatal US results of 40 patients (40/70) diagnosed by referral hospitals did not correspond to our findings. Of the 38 patients with postnatal records, 11 had abnormal neurological development.

Conclusion(s): The outcome of an isolated ASP is usually favorable; however, neurological developmental delay is commonly observed if it is combined with other malformations.