This is true; however, I think it's a jump in logic to say that because women are the only incubators, they must have a child if they get pregnant.
It is a fact that only women can have children, but I don't agree this fact warrants forcing an unwilling mother to go through with a pregnancy.
I do agree if one of the partners doesn't want kids at the moment, it's definitely best if both parties use protection and the situation is prevented. However, even married couples who aren't screwing around face the risk of protection failing.