The newborn baby whose body was found abandoned in woodland at Heywood was born with two ribs missing.
Detectives do not know if this contributed either to her death or her being abandoned in woodland.
The baby was given the name Pearl by officers, meaning precious.
Det Chief Inspector Lewis Hughes, said :
"Pearl was around the age of a fully developed baby in terms of the pregnancy process, capable of being born alive. It may be that she was born alive and lived for a short time, or she may have been still born."
Her naked body was found at 7am on April 4 by a dog walker, close to the River Roch, near Back o’th’ Moss estate.
Her DNA has been checked with national databases, which has shown thousands of potential matches.
Officers are in the process of speaking to several women in the Greater Manchester area as a result of the DNA testing.
Pearl is believed to be white but ethnicity testing suggests there may have been a mixed racial heritage in Pearl’s family.
Anyone with information is asked to contact police on 0161 856 4810 or 07387 705768 quoting incident number 368 of 04/04/18. Reports can also be made anonymously to Crimestoppers on 0800 555 111.