Why are babies born with Mongolian spots?
Emily Schmidt
Updated on May 17, 2026
Mongolian blue spots appear on the skin at or shortly after birth. The spots appear when melanocytes (cells that produce pigment, or melanin) remain in the deeper skin layer during embryonic development. What causes this to happen isn't known. Mongolian blue spots aren't related to an underlying health condition.
Is Mongolian spots genetic?
Mongolian spot is a hereditary developmental condition caused by entrapment of melanocytes in the dermis during their migration from the neural crest into the epidermis.What does a Mongolian birthmark mean?
Congenital dermal melanocytosis — more commonly known as Mongolian blue spots — is a kind of birthmark commonly found in newborns. Also known by the name slate gray nevus, Mongolian blue spots often appear right at birth or in the first few weeks of life. They are harmless and do not need to be removed.Do babies outgrow Mongolian spots?
Mongolian spots — blue-grey or bruised-looking birthmarks which are present at birth. They are more commonly seen in darker skinned people and usually appear over the lower back or buttocks, but can also appear elsewhere on the body or limbs. They may last for months or years, but usually disappear by the age of 4.Can white babies have Mongolian spots?
Mongolian spotsThey are seen in more than 90% of African-American and Native-American babies; 62–86% of Asians;347,348 70% of Hispanic, and 9.6% of Caucasian infants.