That story brings back memories Kerry!   My twins were born in 1973 - before scans - and I vividly recall being examined by a trainee midwife who said "that's an arm, that's a leg, there's another arm, and another, and that's a leg....."!  I stopped her and asked her to get a qualified midwife to examine me, which she did - silently!  She then went to fetch Sister, who prodded and poked in silence and then wrote 'multiple birth' on my card!  Nothing was said to me and when I queried it I was told I would have to wait another six weeks (the due date) to find out!  The next day I went to see my own doctor and told him what had happened.  He was amazed that I hadn't guessed that I was expecting twins but obviously didn't think it necessary to tell me!!!
When I told my mother I was expecting twins she was not at all surprised.  She said "well you are in line for them, your great-grandmother had 2 sets"! 
Strange...nobody thought I should be informed!
Jill