This seemingly most immutable of all social habits changes too, and changes fast.
And, no doubt, things will go on changing.
I do not know for certain, but I feel sure that AI "Artificial Insemination" was invented by a man as labour-saving device.
Knowing certain people's character, and their marked lack of enthusiasm in this particular field, I am convinced that AI will grow immensely popular in no time and that soon it will be the rule rather than the exception.
I foresee the time, not in the distant future, either, when a shy young man will be asked at a party:
"How are you old man? And how's your wife?
Have you AI-ed any more family lately?
What is going to be this time: a boy or a girl?"
And the bashful young man will blush and reply:
"I can't be sure...You see, we don't AI our children.
I've got a "Do it yourself Kit".