Chances my kid is born with heterochromia?

Might be. Most cases of heterochromia are hereditary, or caused by a disease or an injury. Specific causes of eye color changes include: bleeding (hemorrhage), familial heterochromia, foreign body in an eye, glaucoma, or some of the meds used to treat it, injury, mild inflammation affecting only one eye, neurofibromatosis, waardenburg syndrome.