INTRODUCTION

The terms fetal death, fetal demise, stillbirth, and stillborn all refer to the delivery of a fetus showing no signs of life. The terms will be used interchangeably in this topic review; however, it should be noted that parent groups prefer the term stillbirth to the other terms.

The incidence, etiology, and prevention of fetal death will be reviewed here. Diagnosis and management of fetal demise, as well as pathological evaluation of stillborns and counseling parents after stillbirth are discussed separately:

• (See "Diagnosis and management of stillbirth".)
• (See "Evaluation of stillbirth".)
• (See "Counseling parents after stillbirth".)

DEFINITION OF STILLBIRTH

The terminology defining fetal, neonatal, perinatal, and infant death is described in detail separately. A brief synopsis of the definition of stillbirth is provided below. All fetal deaths are not stillbirths, as embryologists define the fetal period as beginning at the end of embryonic period (ie, the eight weeks after conception). (See "Perinatal mortality", section on 'Terminology'.)

• World Health Organization definition — The World Health Organization (WHO) defines stillbirth as a "fetal death late in pregnancy" and allows each country to define the gestational age at which a fetal death is considered a stillbirth for reporting purposes [1]. As a result, some countries define stillbirth as early as 16 weeks of gestation, whereas others use a threshold as late as 28 weeks [2-4]. Fetal deaths under the threshold are considered products of miscarriage (abortuses).
• United States National Center for Health Statistics definition — The standardized definition for fetal mortality used by the United States National Center for Health Statistics (NCHS) is similar to the WHO definition and adds that stillbirth is indicated by the absence of breathing, heart beats, pulsation of the umbilical cord, or definite movements of voluntary muscles [5]. The majority of individual states in the United States use 20 weeks of gestation as the threshold for distinguishing a stillbirth from a miscarriage; the International Stillbirth Alliance also suggests this cut-off [6]. The use of this threshold results in a more reliable estimate of the stillbirth rate than estimates using earlier gestational age thresholds because of the difficulty of reliably capturing data on early gestational losses.