Which of the following is NOT listed as closely associated with spina bifida in the material?

• A. Ductus arteriosus
• B. Chiari II malformation
• C. Hydrocephalus
• D. Both Chiari II malformation and hydrocephalus

Answer: (A)

The question tests understanding of conditions commonly linked to spina bifida. In myelomeningocele, Chiari II malformation is a typical finding where hindbrain structures downwardly herniate, often with hydrocephalus due to disrupted CSF flow from the hindbrain abnormalities. These associations are frequently discussed together because they reflect how spinal lesions can impact brain development and CSF dynamics.

Ductus arteriosus, by contrast, is a normal fetal vessel that connects the pulmonary artery to the aorta and normally closes after birth. It is not a neurological or spinal-related complication, and it isn’t listed as a closely associated condition with spina bifida in the material. Therefore, it’s the one that doesn’t fit with the common associations.