3.2 million stillbirths: epidemiology and overview of the evidence review

Abstract

More than 3.2 million stillbirths occur globally each year, yet stillbirths are largely invisible in global data tracking, policy dialogue and programme implementation. This mismatch of burden to action is due to a number of factors that keep stillbirths hidden, notably a lack of data and a lack of consensus on priority interventions, but also to social taboos that reduce the visibility of stillbirths and the associated family mourning. Whilst there are estimates of the numbers of stillbirths, to date there has been no systematic global analysis of the causes of stillbirths. The multiple classifications systems in use are often complex and are primarily focused on high-income countries. We review available data and propose a programmatic classification that is feasible and comparable across settings. We undertook a comprehensive global review of available information on stillbirths in order to 1) identify studies that evaluated risk factors and interventions to reduce stillbirths, 2) evaluate the level of evidence for interventions, 3) place the available evidence for interventions in a health systems context to guide programme implementation, and 4) elucidate key implementation, monitoring, and research gaps. This first paper in the series outlines issues in stillbirth data availability and quality, the global epidemiology of stillbirths, and describes the methodology and framework used for the review of interventions and strategies.

Figure 1

Stillbirths – the mortality burden compared to other linked global health mortality burdens. Data sources [1,5,6,15,55].

Figure 2

Epidemiological time periods and definitions. *Adapted from Lawn JE, Kerber KJ eds 2006 [56].

Figure 3

Causes of stillbirths in Pakistan according to verbal autopsy after a nationally representative household survey. Pakistan DHS 2006–7, Bhutta et al. [22].

Figure 4

Consistent classification for causes of stillbirths. Source: Provisional classification system for global estimates of cause of stillbirth by the Child Health Epidemiology Reference Group (CHERG), Global Alliance for Prevention of Prematurity and Stillbirths (GAPPS) and Saving Newborn Lives/Save the Children for WHO. Some causes will be systematically missed in verbal autopsy assessments but are still important to delineate for comparability e.g. internal congenital abnormalities and maternal infections.

Figure 5

Search strategy schematic (to March 2008).

Figure 6

Cochrane Library reviews of selected maternal interventions showing those that also report stillbirth outcomes.