Mortality rates in the perinatal period are used to evaluate the outcome of pregnancy and monitor the quality of perinatal (prenatal and neonatal) care. The perinatal mortality rate encompasses late fetal and early neonatal mortality.
The use of standard terminology facilitates comparisons of mortality rates among states and countries. Standard definitions for reporting reproductive health statistics are published by the National Center for Health Statistics (NCHS) (available at www.cdc.gov/nchs)  and are adopted both by the American Academy of Pediatrics (AAP) Committee on Fetus and Newborn and the American College of Obstetricians and Gynecologists (ACOG) Committee on Obstetric Practice [2,3]. The following definitions are recommended and used in this review.
Live birth — The newborn shows signs of life after complete expulsion or extraction from the mother (ie, heartbeats, umbilical cord pulsations, breathing, or voluntary muscle movement). Heartbeats should be distinguished from transient cardiac contractions and breathing distinguished from fleeting respiratory efforts or gasps.
In the United States, the 2002 Born-Alive Infants Protection Act defined live birth as "the complete expulsion or extraction from his or her mother of that member, at any stage of development, who after such expulsion or extraction breaths or has a beating heart, pulsation of the umbilical cord, or definite movement of voluntary muscles regardless of whether the umbilical cord has been cut, and regardless of whether the expulsion or extraction occurs as a natural or induced labor, cesarean section, or induced abortion" .
Fetal death (stillbirth) — Death of the fetus occurs prior to expulsion or extraction from the mother. Fetal death is determined by no signs of life after delivery. Signs of life include heartbeats, umbilical cord pulsations, breathing, or voluntary muscle movement, as noted above. Heartbeats should be distinguished from transient cardiac contractions, and breathing from fleeting respiratory efforts or gasps. (See "Fetal demise and stillbirth: Incidence, etiology, and prevention".)