Would you like to provide examples of how it's highly stigmatized?
I wouldn't call it "highly stigmatized" myself, but I can give you examples of social pressure (all things that happened to me or in my presence):
1) one of my bosses (woman) told someone in our team "Well, you cannot understand it until you have children. A woman never really becomes complete until she has children." The topic had nothing to do with children.
2) A good friend asked me for justifications when finding out that I didn't want to have children, because she could not understand how I could be so selfish. Another laughed at me and said "wow, that is really super-weird."
3) A coworker mentioned that my career was going to slow down because I was hitting prime reproductive years (that was 8 years ago, at 28). When I said "well, that's discriminatory... And I don't want children, so I will not suffer from repeated career breaks", he replied "wow, don't let anyone know you don't want children. That's such a bizarre thing, and you don't want people thinking of you as a weirdo."
4) Every other year, my mother and I have to have a heart-to-heart, because she is convinced that I am going to deeply regret my choice and she is terrified of it for me.
5) A NYC gyno refused me an IUD because "it could make me infertile." This is pretty inaccurate, but I simply countered that I didn't want children anyway. He still refused me treatment, because he felt it was "an inappropriate choice for a woman your age to think she is making this kind of decision." I was 31.
6) A (conservative Catholic) cousin refuses to consider my marriage "valid" because the intention to have children is not at the heart of it.
Now, all these things come from different places in terms of intention, intelligence, and appropriateness, and I don't care that much about any of them (well, except that I am sad to make my mother worry). But they are all examples of social pressure to conform to a model to which many cannot or do not want to conform.
