It says that the babies in the womb looked to be crying at the 28th week.
I think most people would agree that babies are human at this point at least and therefore yes, crying indicates humanity.
I suppose the bigger question related to abortion is what makes us human.
Is it the ability to use nourishment, grow, talk, laugh, cry, feel emotions?
If you believe in souls - just when does a baby gain this 'soul' and is it the soul that makes us human. What are the babies/phoetus' before they gain a soul.
If you believe in reincarnation - just when does the reincarnated self gain the new body?
A shed load of questions without any definate answers.