Autopsy not performed by the Hospital like it was requested, what can be done?

I have someone close to me who delivered her baby at 20 weeks and the baby was not alive upon delivery. She requested an autopsy and even signed the paper for one. She just recieved her reports from the hospital today, a 75 page report, with nothing in there about an autopsy at all. She chose to have the baby cremated. She has the papers showing the cremation,but no autopsy report. She is very upset. I thought the hospital HAD to perform an autopsy in situations like that, especially since she signed a paper requesting one.