he current definition of fetal death adopted by the Centers for Disease Control and Prevention National Center for Health Statistics is based on a deinition recommended by the World Health Organization (MacDorman, 2015). It states that "Fetal death means death prior to complete expulsion or extraction .rom the mother of a product of human conception irrespective of the duration of pregnancy and which is not an induced termination of pregnancy. The death is indicated by the act that after such expulsion or extraction, the etus does not breathe or show any other evidence of lie such as beating of the heart, pulsation of the umbilical cor, or deinite movement of voluntary muscles. Heartbeats are to be distinguished rom transient cardiac contractions; respirations are to be distinguished .rom fleeting respiratory eorts or gasps."
Reporting requirements for fetal deaths in the United States are determined by each state, and thus, criteria difer signiicantly (Chap. 1, p. 3). Most states mandate reporting of deaths of fetuses that are 20 weeks' gestation or older or have a minimum birthweight of 350 g (roughly equivalent to 20 weeks) or some combination of these two. However, several states require reporting of fetal deaths at all periods of gestation, and one sets the threshold at 16 weeks. lternatively, two states require reporting of deaths for fetuses with birthweights of 500 g, which approximates that at 22 weeks. here is substantial evidence that not all fetal deaths for which reporting is required are actually recorded (MacDorman, 2015). This is most likely for those at earlier gestational ages.
Comparisons of rates among countries are limited by incomplete fetal death data. Namely, internationally, less than 5 percent of neonatal deaths have formalized documentation (The Lancet's Ending Preventable Stillbirths Series Study Group, 2016d). Further, comparative analyses using birthweight versus gestational age among countries do not provide equivalent results. For example, in the United States, if stillbirth would be deined by a birthweight �500 g, the stillbirth rate would be reduced by 40 percent compared with
FIGURE 35-3 Fetal mortality rates by period of gestation: United States, 2000-2013. (Data from MacDorman MF, Reddy UM, Silver RM: Trends in stillbirth by gestational age in the United States, 2006-2012, Obstet Gynecol. 2015 Dec;126(6):1146-1150.) a 22-week-age deined cohort (Blencowe, 2016). To address nomenclature diferences, some have called for changes to the current deini tion a oseph, 2015).
Overall, fetal mortality rates in the United States have remained relatively unchanged since 2006. However, the infant mortality rate has declined 11 percent, and both rates are now essentially equal (MacDorman, 2015). Three fetal mortality epochs are generally described: early (less than 20 completed weeks' gestation); intermediate (20 to 27 weeks); and late (28 weeks or more). The fetal mortality rate at 20 to 27 weeks in 2013 declined 3 percent from the prior year. Between 2006 and 2012, rates were essentially unchanged in this age group. The late fetal mortality rate has been relatively unchanged since 2006 35-3).