The longest recorded time between the death of a mother and the birth of a live, healthy baby is 3 months, according to The Huffington Post. This was only possible because the mother was brain-dead and kept under life support both before and after dying.
A mother that is brain-dead, but otherwise capable of retaining automatic bodily function through life support, is medically considered a dysfunctional incubator. Numerous cases exist in which brain-dead mothers have given birth to healthy infants, states the Los Angeles Times, but the nature of death is a critical factor in determining whether the birth can be a successful one. No evidence exists suggesting that it is possible for a mother killed by bodily trauma or disease to give birth to a healthy infant, and every successful case has occurred with life support being administered both before and after the declaration of death.
While the presence of life support may seem to suggest that the mother was not technically dead in any of the described cases, The National Library of Medicine defines brain-death as being as absolute as circulatory or respiratory death. In cases of circulatory or respiratory death, the deceased mother's inability to provide blood and oxygen to the fetus means it has no chance of survival and will die in less than a minute.