Among 127 samples of alcohol-treated embryos, 34 (27%) had various degrees of incomplete neural tube closing (Figure 1); this compares to 3 (2%) out of the 139 controls. These openings in the neural tube mostly occurred in the head fold, although delayed or incomplete neural tube closure in midbrain and hindbrain was also seen. The abnormalities and developmental delays are clearly more severe in ALC-NTO than in ALC-NTC subgroups, particularly in development of the neural axis including hindbrain, midbrain, forebrain, otic vesicle.
