Also by choice - to the point of having my tubes tied. I never felt the "baby crack" of obsessively needing
a child in my life. I had two instances of "You know, I think I'd like to have a baby", and both feelings lasted less than two weeks. My ex-husband was in the camp of "Oh, you'll change your mind". By the time I hit thirty, I told him "You want a baby so damn bad, you
get pregnant and keep it in the shed!"
A friend and I were discussing this matter recently - she's more interested in adopting than having her own. Older children are more independent, can give you feedback, and they're young enough to be healed of whatever trauma led them into the state home. I've noticed it's always about "omg i want teh baybee part last 4evar" with others instead of "Think of how interesting and amazing it would be when they're old enough to think and learn and talk and do things! With their own personalities!"
It amuses me that a biological truism is treated as a reason and/or payment for existence. If you've got the drive and the means, then do it. Just don't force your Religion of Motherhood on me.