Collection coverage tables show the places and time periods of original records published. Check the coverage table for the collections you searched which did not include your ancestor. Gaps in the online collection may require searches in other records or original birth records at an archive.
*[http://user.xmission.com/~jsvare/FR/IA_FRB.html County death holdings, Iowa]
*[[Iowa Deaths and Burials, Coverage Table (FamilySearch Historical Records)]]