The central nervous system of a growing foetus begins with a basic structure called the 'neural notch' that folds in to shape the 'neural tube'. This at that point forms into the spinal line and mind. By day 28 after origination, the neural tube ought to be shut and melded. On the off chance that it doesn't close, the outcome is a neural tube deformity. Much of the time, these deformities can be determined amid pregnancy to have ultrasound filters and, infrequently, with different tests, for example, amniocentesis (investigating an example of amniotic liquid).