'Get her pregnant' by dangling the carrot of marriage. ? Not sure about most women but I am an autonomous adult human female who attended school biology classes.
Whilst there I learned the way to control my own fertility. No one 'got me pregnant' we planned a family to arrive at a time of our choosing. (Yes I am aware we were lucky not to suffer the distress of infertility) My friends and family have been incredibly lucky not to suffer the phenomenal rates of contraceptive failure unique to MN posters. So no 'accidents' here.
I then met a man who I thought would be a good person to raise a family with. So I discussed it with him and he agreed. Then, because I am female and therefore the one to reproduce and would be the one to have to take time out of the workplace in order to have children - I explained that the legal contract of marriage would be required if I was going to be in a more financially vulnerable position during childbearing /child rearing. As he is an adult human male who wanted the best for me and our potential family, he agreed that this was a realistic and sensible expectation on my part.
We got married. I then changed my surname to match his. I did this for two reasons. 1. I absolutely hated my surname. It is hideous and I've always hated it. 2. As a lifelong feminist, I believe that it was my choice. Choice is the thing that I had fought for as a feminist from the 1970s. Choice in all aspects of my life. I had the right to choose. So I chose his name because I wanted to. I could just have easily chosen to keep mine, double barrel it, ask him to change to mine or invent an entirely new one . That is the beauty of choice. No one dictates. No choice is right or wrong. It's a preference.
The children then had the same name as both their parents. Although one of my girls chose to add my hideous surname to hers when she was a teenager. Good for her. She made a choice.
I am perplexed as to why anyone would care what last name anyone wishes to give themselves or their children. It really doesn't matter one way or the other. The days when it was a sign of the oppressive patriarchy are gone. They went when you got to choose.