Fetal mortality—the intrauterine death of a fetus at any gestational age—is considered a major but often overlooked public health issue. It is estimated that there are more than 1 million fetal losses each year in the United States, and most occur before 20 weeks’ gestation. Fetal mortality data from the National Vital Statistics system are usually presented for fetal deaths at 20 weeks’ gestation or older (MacDorman, 2012). Using this definition, there are nearly as many fetal deaths as infant deaths (Fig. 35-1). As shown in Figure 35-2, fetal deaths rates at 20 weeks or more are gestational-age related, reaching a nadir that plateaus between approximately 27 and 33 weeks. Following this, there is a progressive rate increase.
Percent distribution of fetal deaths at 20 weeks’ gestation or more, and infant deaths: United States 2006. (From MacDorman, 2012.)
Fetal mortality rate per 1000 births by single weeks of gestation: United States, 2006. (From MacDorman, 2012.)
Definition of Fetal Mortality
The definition of fetal death adopted by the Centers for Disease Control and Prevention National Center for Health Statistics is based on the definitions recommended by the World Health Organization (MacDorman, 2012). This definition is as follows:
Fetal death means death prior to complete expulsion or extraction from 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 fact that after such expulsion or extraction, 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. Heartbeats are to be distinguished from transient cardiac contractions; respirations are to be distinguished from fleeting respiratory efforts or gasps.
Reporting requirements for fetal deaths are determined by each state, and thus, requirements differ significantly (Chap. 1, Vital Statistics). Most states require reporting of fetal deaths at 20 weeks’ gestation or older or a minimum 350-g birthweight—roughly equivalent to 20 weeks—or some combination of these two. Seven states require fetal deaths before 20 weeks to be reported, and one state sets the threshold at 16 weeks. Three states require reporting of fetal deaths with birthweights 500 g or more—roughly equivalent to 22 weeks. There is substantial evidence that not all fetal deaths for which reporting is required are actually recorded (MacDorman, 2012). This is most likely at the earlier gestations of various state requirements.
The overall fetal mortality rate at 20 weeks or more for the United States has steadily declined since 1985 from 7.8 to ...