I guess I'm a little weird in this one.
I told my mom that we would welcome children anytime once DH and I were married. Not exactly saying we're TTC because that would feel too much like announcing we're having sex all the time, but more like it could happen anytime, so when the announcement came, it wouldn't be as big of a surprise and they would know that we were working toward it, not a big accident.
That being said, my parents have NEVER asked for a grandbaby. Ever. Even of my sister who's been married for 5 years, not even of me and DH now that we're married. My mom actually said "If you want to wait, don't feel like you can't". when I brought up starting a family with her. I think they just want us to do what's right for us, and know the pressure to start a family can be really intense once you're married. My parents waited 5 years intentionally, and it was wonderful for them. Except they were 18 when they married, so it's a little different.
His parents are WAY MORE pushy about more grand kids, and we really skirt the idea with them. It just doesn't feel right to feed the pressure on the scenario.
Our closest friends all know, but we also all know when they are trying. It's our social support group. Many have had problems, or infertility, miscarriages, early loss of children, and it is comforting to have them and their sage advice and support in this time.
Sometimes I think there's a ton of pressure to keep it all a big secret, and then people go through extremely difficult losses all alone. Realistically, there's probably a large number of people who have been through a miscarriage, and to me, to talk to friends about it, have their support, their love, their extra care during those times, would maybe make it easier?? I feel like knowing which friends are struggling makes me a better friend for them. I can ask how they're doing. I'm more cautious about parading my own TTC around. I know when they've had a really rough week and I can do a little something extra special to love on them. I know that they have their spouse, but men don't always deal with things the way woman do, so why shouldn't we support our girlfriends too?? And I know that having my mom's or dad's support would also help in times like that. Hearing that they would love an adopted grandchild or a grandchild from IVF and purchased sperm or eggs, or never having grand children period, would make it a little easier to deal with, compared to them adding pressure without knowing our struggles.
But that's me. I feel like by just coming clean with "We're trying", folks back off and just give their support without layering on the pressure.