Table 1.

Terms and definitions

Term	Definition
Miscarriage	Foetal loss before 20 weeks of pregnancy (measured from the last menstrual period)
Foetal death	Death in utero after 20 weeks from the last menstrual period. Used as an indicator of prevalence of stillbirth
Birth	Covers all pregnancy outcomes after 20 weeks of pregnancy (measured from the last menstrual period)
Birth prevalence	Used in place of “incidence” to describe the frequency of new cases as they present to health services. Expressed in terms of affected births per 1000 live births. World Population Prospects (WPP) estimates provide the denominator, and in WPP the term “births” applies only for live births
Baseline birth prevalence	The birth prevalence that would obtain in the absence of any intervention
Actual birth prevalence	Actual births/1000 live births, allowing for the effects of interventions before or during pregnancy
Total birth prevalence	Includes all outcomes of affected pregnancies after 20 weeks’ gestation (termination of pregnancy, foetal death/stillbirth, live birth). Expressed as total affected births /1000 live births
Live birth prevalence	Affected live births/1000 live births
Optimal care	Standard of care available in high-income settings with equitable access to services, at any given point in time
No care	The level of care available in the absence of any supportive medical services
Early mortality	Deaths in children under 5 years of age
Severe disability	Disability plus significantly shortened life expectancy
Less severe disability	Disability with less effect on life expectancy. Ranges from less severe forms of spina bifida to “well on treatment” (e.g. congenital hypothyroidism)
Effective cure	A disorder that has been sufficiently corrected to allow affected individuals to live their lives free from continuing medical care, and to achieve life goals such as independent living, finding a partner, reproductive success, even with some persisting problems. It does not mean complete correction with no residual problems