I had my mum, XP & a friend at my first birth, DH & a friend for DS1, DS2 & DD2.

The advantage of having someone else there (this is just for us ) is that they are support for your DH as well. As Carrie said, they can tag-team with massage & support. For me it meant I was never on my own, even when DH did have to go to the toilet, get a coffee, etc. and that was how I wanted it.

The most important thing is that you are both comfortable with who you have there. Both DH & I would rather not have anyone else there if it's not the right person, IYKWIM? And we considered the fact too that some people who are great company in everyday situations might become a bit grating in a delivery room. We chose carefully

So go with whatever you feel comfortable with