FWIW my supply was not affected at all and I never came accross anything to suggest that in my reading?? The biggest concern to me was that in theory, the ink particles are small enough to pass into breast milk. No one knows for sure and no one knows what risk, if any, this would pose to the baby. Most stuff I read suggested it was a very small risk, particularly with a small tattoo.

There's quite a few threads on the ABA site if you're interested, and one with posts from a tattooist too if I remember correctly.