I don't have this personally but as a midwife I have seen it done (usual after a prem birth or m/c) and it has drastically increased the pregnancy duration. One lady had her septum removed after two prems (26 &28wks) and went to full term with bub no3. And the other lady had a few m/c's and went on to have a healthy bub which was a little early (around the 34-35weeks by memory)

I think alot of m/c that occur due to the septum is due to the emby implanting on the septum not uterine wall so once removed you also remove this risk. And prem labour can start as the uterus is divided in two and often not large enough to hold a term baby. I also know a lady who had this and she had 5 term babies (4vaginal births and 1 c/s) Her 4 babies born vaginally were all in the left side but no5 was in the right side and couldn't be born naturally.

I have personally only seen positive outcomes once the septum was removed.