From an article I found by Karen Hambridge....
"UP until the 1980s doctors labelled pregnant women over 30 as 'geriatric mothers'. By 1990 the term 'elderly prima gravida' - older mum, first baby, was given to anyone over 35. Now most health authorities class an older mother as 37."
I heard the term Prima Gravida, and thought that there was something terribly wrong with my baby (it was the "grav" bit, sounded awful!)
Fact is, the age goes up and up, for Dad's too, my friend has recently become a 1st time Dad at 50