Could Women Be Trusted With Their Own Pregnancy Tests?

I loved this story which appeared in the NYT today about the woman who invented the home pregnancy test.  Unrecognized, uncompensated and disrespected for decades...she finally got the credit she was due.

Margaret Crane, 1965.

Why did society make laws to prevent women from performing such tests?  What was the logic - other than exercising some power over an entire gender?  Much the same as slavery but 'gentler.'