Personally I won't go for a tattoo and I'm glad that I was not born in the pre-colonial era where tattoos in the form of tribal marks are given to children.
I have also heard of the myth for children of still both. I heard that giving them such tribal marks or tattoos would make the baby not to be accepted in the spirit world thereby allowing the child to remain in the land of the living.
RE: The Myths, Traditions, and Modern Realities of Tattoos in Yoruba Culture