What does #tomyunbornchild mean on twitter?

[Southern Belle]

I know this is a stupid question but everyone that I follow on twitter is tweeting #tomyunbornchild and then after that some about "their unborn child". I'm just a country girl without the daisy dukes what do you expect?
@kelly sorry you took this the wrong way. i would never troll, never had.

[Pickles the Wise]

I guess it's tweets they want to show their kids later. Inspirational and all that. I personally think good messages are more than 100 characters.

[kelly.]

I can't tell if this is a troll or a legit question..

[Esme]

it basically means that that's what they would want their future baby to know.(:

[HeStoleMYHeart]

Something they're saying to their future kid