The baby is dead. Dead equals ghost and ghost means haunting. Which means yes. The women's vagina would be technically haunted. Now I feel sorry for the women for her lose however she should see a priest or something to get her vagina unhaunted or "uneatable" which means the baby would not be forgotten but the ghost will be gone.
Most miscarriages occur within the first few weeks of pregnancy, and it is possible for a woman to miscarry before even realizing she's pregnant. How could a woman know to get herself 'un-haunted' if she doesn't even know she miscarried? If this were true, there's a lot of haunted vaginas out there.
And if you want to get into the realm of the paranormal, a death doesn't automatically make a haunting either.