Is this a bruise?
When you take your baby's clothes off and check her all over, you may see dark spots on her buttocks or back. These are called Mongolian spots.
The name has always bothered me, because they have nothing to do with Mongolia. I see these spots in at least half of the babies I examine. If I see them on your baby, I try to remember to write on the medical record that I have seen them, and to make sure that you are aware of them. People who don't know about babies may mistake them for bruises.
They are NOT bruises. They are naturally occurring areas where the skin cells contain more pigment. They may occur anywhere on a baby's back, buttocks, arms, legs, hands or feet.
Mongolian spots gradually fade away in two or three years. You don't have to do anything about them. However, make sure your baby's doctor makes a note of them in the medical record. A note in a medical record can clear an unfounded accusation of abuse.
Thanks to Janelle Aby MD, Stanford School Of Medicine, Newborn Nursery, and Lucille Packard Children's Hospital for the use of occasional photographs.