Many a mother reminds her growing daughter, from time to time as the youngster is better able to understand her own future and upcoming biological role, "girls get pregnant." I have a brother and I know boys are told "don't get girls pregnant."
Pregnancy may take two people, but once achieved, it is by definition, a strictly female process. There are indeed laws about paternity and child support and laws about a father's responsibility to his children, but the pregnancy - carrying the child and giving it birth - is what makes us females.
That means that 53-percent of the human race carries the young in their bodies - whether or not they choose to exercise that option. Sometimes women are infertile and that is a whole other issue I will not get sidetracked into, but what unites us as women - whether we have ever born children or not - is our collective and overarching social role and many laws about us are written with that biological reality as a backdrop. Many religious codes are written with that as a backdrop. Many social norms stem from that and while I readily agree men rape other men, the crime of rape has a particular significance when it comes to women.
Social institutions such as courtship - let alone marriage - have this biological reality as an under-pinning. Those opposed to "test tube babies" or who see cloning as dangerous and irresponsible reveal their own thoughts on the meta-message about the meaning of the womb.
And as many a mother will, mother will sit down with her daughter and in hushed tones and sober voice explain what happens when a girl lets a boy "have his way." In another era - and maybe even today - if a girl had given access to her birth vault to another, others would not want her and we're not just talking intercourse. A widow (or widowers, as this does include men) or divorced person will find "replacement" mates to sometimes be reluctant to take on the mate-and-brood.
A billion years back in the pre-Cambrian organic soup - or was it Eden, take your pick - simple cell division (like in the "eternal" amoeba) was replaced by sexual reproductions. It was then that everything changed profoundly. There now were "sexes" and sexual reproduction. Once the process was underway, it could not be willed to stop. Once the female was impregnated, short of a gestation malfunction or the female's death - the process ground inexorably to its conclusion.