HELP! Baby announcements

Nanci
Hiya! My husband and I just started trying for baby #4 (I have 2 from a previous relationship, so baby #2 for him). His parents only have 2 biological grand children and will not be getting more unless it's from us so I would love to hear some ideas on how to make announcing this pregnancy to them really special because this may be our last one. Hellllpppp!!