The World Health Organization’s definition, also adopted by the United Nations and the National Center for Health Statistics, a fetal death is death before the complete expulsion or extraction from its mother of a product of conception, irrespective of the duration of pregnancy; the death is indicated by the fact that after such separation, the fetus does not breathe or show any other evidence of life, such as beating of the heart, pulsation of the umbilical cord, or definite movement of voluntary muscles.

For statistical purposes, fetal deaths are classified according to gestational age. A death that occurs at 20 or more weeks of gestation constitutes a fetal death, and after 28 weeks it is considered a late fetal death.

Therefore, a fetal death rate is the number of fetal deaths with stated or presumed gestation of 20 weeks or more divided by the sum of  live births plus fetal deaths, stated per 1,000 live births plus fetal deaths, and a late fetal death rate is the number of fetal deaths with stated or presumed gestation of 28 weeks or more divided by the  sum of live births plus late fetal deaths, stated per 1,000 live births plus late fetal deaths.