A 37-year-old man has been arrested after an 11-year-old gave birth in hospital to a girl.
The young girl went into labour at a west London hospital on 5 May, a police spokeswoman said.
Four days later, officers from the child abuse investigation team made the arrest at a residential address in Uxbridge, west London.
A spokesman for Hillingdon Council said the young mother and her baby are now in the care of the local authority.
The man has been bailed to return to a west London police station in July.