Spinal tap during pregnancy

Ariella
Has anyone ever had a spinal tap while pregnant?? I have swelling in my optic nerve, and my neuro opthalmologist wants to test the pressure of my spinal fluid in order to determine whether I need medication or not (trying to stay away from the meds until 20 weeks, so we'll see)
But if anyone is or has gone through something like this please comment, I just want to hear that I'm not alone in this....
Thanks in advance!