I think it is personal choice. Marriage isn't always forever, and how different is it really, than a couple in a stable loving relationship, that can provide for that child? (Apart from the obvious, public ceremony with dress/piece of paper/party )
I would personally like to be married before I eventually have children, but thats just because I'm super idealistic and actually think love is a bit of a fairytale. I'm sure it'll get knocked out of me sooner or later!
It's personal choice though really, I was 2 when my parents got married and my sister was a baby... so yeh, I have nothing against it. Life doesnt always go to plan either so even if you'd like to be married you might not be!
I think all that really matters is a loving and stable relationship, some choose to show this with marriage and others don't. Personally, I would prefer to be married before having children but I can see how it isn't really necessary for raising children.
personally i think you dont have to be married to have children, but i've been brought up to be hindu and they believe strictley you should be married to have children and say if im wrong but i think thats the same for christians to but also it depends if the people even need to get married as at the end of the day it is just a piece of paper, so aslong as the 2 are commited and know they'll ' stay together forever' it doesn't matter
Marriage isn't really necessary, as long as the people are in a suitable personal, and financial position to be having a child. If they're not, then they should wait till they are in a position to do so.