Figure 2.

Haematoxylin-eosin staining of the aqueduct throughout gestation. A. Transverse section through a wide-open aqueduct of a control fetus (40 weeks GA). Scale bar = 500 μm. B. Transverse section through the aqueduct of a fetus with MMC (22 weeks GA). The lumen appears narrow or slit like. Scale bar = 100 μm. C. Transverse section through the aqueduct of a fetus with MMC (21 weeks GA). Several infoldings are present (i.e. forking). Scale bar = 100 μm. D. Secondary damage at the aqueduct of a fetus with MMC (21 weeks GA). Arrowheads indicate haemosiderophages (I), gliosis (II), and recent bleeding (III). Scale bar = 100 μm. E. Transverse section through the aqueduct of a fetus with MMC (37 weeks GA). The figure shows sub-ventricular rosette formation (R). Scale bar = 50 μm.