ONTDs or Open neural tube defects are problems in which the brain, spinal cord, or spine forms while a baby is growing in the mother’s uterus occurring in about 1 in every 1,500 newborn babies yearly.
While mom is pregnant, the child's brain and spine begin as a flat plate of cells that rolls into a tube called the neural tube. This process is completely formed within 28-32 days after conception. If any part of the neural does not close it it considered an open neural tube defect. The opening can be left exposed or covered with skin or bone.