Any question answered...

When I was younger, or not even that long ago, I'm sure people referred to finding out the sex of a baby.

Now everyone always says gender.

1. Is this true or am I miss remembering.
   
2. Why would people now use gender, when my understanding is the general progressive view is gender is a societal construct, where as sex is xx vs xy. So isn't "sex" even more appropriate now than before?
   
   

Cheers.