There was a time when eugenics was all over SF written by women. And I was reading SF during that time, but I was a kid, and didn't notice it.

I am curious about it now, and I wonder:

What time period was that, exactly?
Is my sense that it was more common in books by women than by men correct? If so, why?
What were they thinking?
Why did it stop?

Would you say that these are books I should include if I make an investigation of the phenomenon?