"Rainbow baby" curiosity question

Dr
Please don't attack me because this is a honest question, but if you experience a chemical pregnancy, or more than one chemical pregnancy (ecspecially if those pregnancy's were back to back) then is the child that is finally born considered a rainbow baby?
I'm not trying to minimize what other women go through or grasp for straws on the term rainbow baby. I'm genuinely curious to know what constitutes the term "rainbow baby"