Spina Bifida is the most common permanently disabling birth defect that is associated with life in the United States. It’s a type of neural tube defect (NTD) that occurs when a babies neural tube fails to develop or close properly – the literal meaning for Spina Bifida is “split spine”. Typically occurring within the first 28 days of pregnancy, while the neural tube is forming, Spina Bifida often occurs before a woman knows she is pregnant.