Hello Thank you for placing your query at Health Care Magic Certain diseases and drugs can cause darkened complexion. If that is the case then it can be treated. Consult your pediatrician or dermatologist for the same. However if the baby s natural complexion is a bit on the darker side, i suggest you do not lay too much stress on it. Just maintain good hygiene of the skin. Use appropriate skin creams according to age and then according to seasons. But this advice is not for fair skin. It is a generalized advice for any complexion. Not fair complexions are also very pretty . So you should stop worrying about it. Hope that helped God bless you