To me a trafficked baby, is one where the baby is taken without consent.
Such as women who are forced to give their child up because of being held.
Where to draw the line here, though?
Aged 16 in a mother-and-baby home in the 1950s, having your baby physically taken from you = trafficking (presumably)
Aged 16 in a mother-and-baby home in the 1950s, being pressured into signing the adoption forms for your baby because you're told you have no choice = also trafficking?
Aged 16 in a mother-and-baby home, told it's entirely your choice, but knowing there's no social support for you as an unmarried teenage mother, the baby's father doesn't want to know and your parents will kick you out?
Aged 26 in an Indian baby factory, signing up voluntarily, but being desperately poor and knowing this is one of the few available ways you have to earn the money you need for your family?
Aged whatever in a country that allows commercial surrogacy, willingly signing the contract to hand over your baby at birth, then changing your mind after you hold the baby in your arms and being told nope, sorry, your decision's been made?
I think if you're exchanging people for money, it's trafficking.