My first response to this question was to also say wait. But I guess when I think about it, I think that you know them best, and know whether they still have a lot of fear of miscarriage or something going wrong with this pregnancy. Having struggled to get pregnant(5 IVF's and having a miscarriage) I know what it feels like to be fearful. You could ask them in a very sensitive way...or giving it at the baby shower would be another relatively safe time to present it. It is very nice that you have the empathy to think about this..