The Course and Neonatal Outcome of Choroid Plexus Extension to the Anterior Horn at the Routine Anatomy Scan

Abstract

Objectives Our objective was to examine the pregnancy course and immediate neonatal outcome of fetuses with an isolated extension of choroid plexus (CP) to the anterior horn during the second trimester. Methods We prospectively collected the cases referred to us between July 2012 and January 2021 with isolated finding of CP extension to the anterior horn. Relevant clinical and demographic information was recorded, and a full anatomy scan including a comprehensive neurosonogram was performed. In cases of confirmed isolated extension of CP to the anterior horns, women were offered further investigation including fetal MRI, and ultrasound follow up. Results We collected 29 eligible cases for analysis. The mean gestational age (GA ± SD) for diagnosis and referral was 19.24 ± 2.3 weeks. No other intracranial anomalies were detected in any of the cases, and the finding resolved at 25 ± 2.6 weeks. The average extension length and width to the anterior horn were 0.7 ± 0.3 cm, and 0.5 ± 0.1 cm, respectively. Eleven fetuses (38%) had choroid plexus cyst (CPC) in addition to the extension. Ten patients (35%) completed a fetal brain MRI, with no identified abnormalities. Gross neurological exam and Apgar score at birth were normal. Conclusion Extension of CP to anterior horn with or without CPC at mid‐trimester seems to have spontaneous resolution with likely a good prognosis and no further implications.

The normal 14–18 gestational weeks “parasagittal complex” view of the fetal brain. A 3D transvaginal neurosonographic study

“…In our study, we showed that by 14–16 weeks, the CP in one or both hemispheres may still reach the level of the foramen of Monro or extend anteriorly to it, before subsequently moving toward its final posterior location. Additionally, it has been shown that later persistent anterior extension of the choroid plexus (CP) may be seen later in pregnancy, usually representing a benign finding, with a concomitant presence of a CPC in the anterior horn in 38% of cases 24 …”

“…Additionally, it has been shown that later persistent anterior extension of the choroid plexus (CP) may be seen later in pregnancy, usually representing a benign finding, with a concomitant presence of a CPC in the anterior horn in 38% of cases. 24 The process of neuronal proliferation and migration results in a transient lamination pattern of the cerebral wall. 2,3 Postmortem histologic studies, 2,25 has identified seven distinct layers at 17 weeks.…”