Back when I was pregnant with #4, one of our neighbors asked if one could "do that"? I said, "There's no 'doing that'; it's already 'done.' The baby is on the way." Now that we're expecting #6, they don't know what to say at all.
Of course, my doctor is at a Catholic hospital, and he envies us. He's said that he thinks it's great that we have so many, and the nurses all remember me from back when #2 was in the NICU. I've been around there a lot.
Any time, however, that I have had cause to go to any other hospital, they're . . . not so enthusiastic. When I was pregnant with #4, this one doctor seemed irritated, but when I went back pregnant with #5, he seemed personally offended that I was having another one. I avoided even seeing him now that I'm expecting #6.
(And please keep praying for me with this pregnancy. It's my hardest one so far, and it's killing me. :( )