stillbirth (plural stillbirths)
- The birth of a dead fetus; the delivery of an infant which is dead at birth.
- (modern medicine) The birth of a dead fetus after 20 weeks of gestation.
Many uses of the term stillbirth (and almost all modern medical uses) differentiate it from miscarriage, for either of two reasons. (1) In the older and broader senses of the terms, the concepts are distinct but are often instantiated together, because many stillbirths (where a stillbirth is any event where a baby is born dead) result from miscarriage (where a miscarriage is any instance of carrying [gestation] being interrupted prematurely). However, occasionally fetuses die during or right before full-term birth (for various reasons), in which case a stillbirth with no miscarriage has occurred, in these older and broader senses of the terms. (2) More importantly, regarding current usage, the modern medical senses of the terms are generally defined mutually exclusively with a dividing line at the gestational age of 20 weeks (which represents periviability), reserving the term miscarriage for earlier events and the term stillbirth for later events.