Hi and welcome to the Chiari forum.
First, u had decompression b4 u were pregnant or after, sorry I am not following??
I do not understand as I had a pregnancy test b4 my surgery or ne meds given even tho I had not had a period for 12 yrs....
Next ask for ur surgical report, find out just what was done during ur surgery,. the type...as to how much they had to do, laminectomy, duraplasty and type patch used....
Have u had a post op MRI to check CSF flow and see how things have healed?
Request copies of all testing b4 and post op and find out if u may have something else related to chiari going on now, or if it is a post op issue.
I don't have experience with pregancy and Chairi, but I just wanted to say Congratulations to you and your sweet baby. I'm sure everything will be o.k., but having a Dr answer these questions for you will be reasurring. Wishing you a blessed New Years.
Linda :)