antenatal care coverage
Percentage of women attended at least once during pregnancy by skilled health personnel because of their pregnancy.

birth weight
The first weight of the fetus or newborn obtained after birth. This weight is best measured within the first hour of life before significant postnatal weight loss occurs.

case
A person in the population or study group identified as having a specific health problem or disease of interest.

case definition
A set of standard criteria for deciding whether a person has a particular disease or health-related problem. Criteria can be clinical, laboratory or epidemiologic.

case-fatality rate (CFR)
The probability of death among diagnosed cases of a specific health problem or disease. The CFR is defined as number of deaths due to the disease in a specified time period divided by the number of cases of the disease during the same period.

cause-specific death rate
The number of deaths attributable to a specific disease in a given population in a given time period (usually expressed per 100,000 persons per year).

contraceptive prevalence rate (CPR)
Percentage of women of reproductive age who are using (or whose partner is using) a contraceptive method at a given point in time. In practice the CPR is generally reported on women who are currently married or in union, which should be stated accordingly.

crude birth rate (CBR)
The number of live births in a given period per 1,000 people in the same period. Usually expressed per year.

crude death rate (CDR)
The number of deaths per 1,000 people in a given year.

deliveries attended by skilled health personnel
Percentage of deliveries attended by skilled health personnel irrespective of outcome (live birth or fetal death).

• skilled health personnel or skilled attendant
  Doctors (specialist or non-specialist), and/ or persons with midwifery skills who can diagnose and manage obstetrical complications as well as normal deliveries. (Traditional birth attendants, trained or untrained, are not included.)
   

• person with midwifery skills
  A person who has successfully completed the prescribed course in midwifery and is able to give the necessary supervision, care and advice to women during pregnancy, labour and the postpartum period. This person is also able to conduct deliveries alone, to provide lifesaving obstetric care, and to care for the newborn and the infant.
   

epidemiology
The study of the patterns of human disease, health and behaviours.

fetal death (deadborn fetus)
Death prior to the complete expulsion or extraction from its mother of a product of conception, irrespective of the duration of pregnancy. The death is indicated by the fact that after such separation, 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.

incidence rate (IR)
The number of new cases of a health problem or disease in a specified time that occurs in a population at risk of the disease in the same time period. The rate is expressed per 100, 1,000, 10,000 or 100,000.

live birth
The complete expulsion or extraction from its mother of a product of conception, irrespective of the duration of the pregnancy, which after such separation, breathes or shows other evidence of life, such as beating of the heart, pulsation of the umbilical cord, or definite movement of voluntary muscles, whether or not the umbilical cord has been cut or the placenta is attached. Each product of such a birth is considered liveborn.

low birth weight
Less than 2,500 g (up to and including 2,499 g).

maternal death
The death of a women while pregnant or within 42 days of termination of pregnancy, irrespective of the duration and the site of the pregnancy, from any cause related to or aggravated by the pregnancy or its management, but not from accidental or incidental causes. Maternal death is subdivided into two groups:

• direct obstetric death
  Those deaths resulting from obstetric complications of the pregnant state (pregnancy, labour and puerperium), from interventions, omissions, incorrect treatment, or from a chain of events resulting from any of the above.
   

• indirect obstetric death
  Those deaths resulting from previously existing disease or disease that developed during pregnancy and which was not directly the result of obstetric conditions, but which was aggravated by the physiologic effects of pregnancy.
   

maternal mortality rate
The number of maternal deaths per 100,000 women of reproductive age (15-49).

maternal mortality ratio
The number of maternal deaths per 100,000 live births during the same time period.

neonatal mortality rate
Number of deaths in the neonatal period during a given time period per 1,000 live births during the same time period.

neonatal period
Commences at birth and ends 28 completed days after birth. Neonatal deaths (deaths among live births during the first 28 completed days of life) may be subdivided into early neonatal deaths, occurring during the first seven days of life, and late neonatal deaths, occurring after the seventh day but before 28 completed days of life.

perinatal period
Commences at 22 completed weeks (154 days) of gestation (when birth weight is normally 500 g) and ends seven completed days after birth.

perinatal mortality rate
Number of deaths in the perinatal period during a specified period of time per 1,000 total births (live births plus fetal deaths) during the same period of time.

post-neonatal mortality rate
Number of deaths after 28 days up to, but not including, one year of age during a given time period per 1,000 live births during the same period.

pre-term
Less than 37 completed weeks (less than 259 days) of gestation. Pre-term births are also referred to as premature births.

prevalence rate
The proportion of the population that has the health problem or disease under study. The prevalence rate is expressed as the number of existing cases of the disease at a specified point in time in the total population. The ratio is expressed per 100, 1,000, 10,000 or 100,000.

proportion
A fraction where the numerator is a subset of the denominator.

random sampling
A method of selecting a sample whereby each element in the population has an equal chance (probability) of being selected for the sample.

rate
A measure of the frequency of some event in a defined population at a specified time. In a rate, the numerator is a subset of the denominator. The rate is expressed per 100, 1,000, 10,000 or 100,000.

ratio
A measure of the frequency of one group of events relative to the frequency of a different group of events (e. g., maternal mortality ratio is the number of maternal deaths per 100,000 live births). The ratio is expressed per 100, 1,000, 10,000 or 100,000.

relative risk
A measure of the incidence of a condition in those exposed to a particular factor in relation to the incidence of that condition in those not so exposed.

spontaneous abortion or miscarriage
A fetal death in early pregnancy. At what gestational age (point in pregnancy) a miscarriage becomes a stillbirth for reporting purposes depends on the country's policy.

stillbirth
A fetal death in late pregnancy. At what gestational age (point in pregnancy) a miscarriage becomes a stillbirth for reporting purposes depends on the country's policy.

surveillance
A dynamic process in which data on the occurrence and distribution of health or disease in a population is collected, organised, analysed and disseminated.

total fertility rate
The number of children who would be born per woman, if the woman was to live to the end of her child-bearing years and bear children at each age in accordance with prevailing age-specific fertility rates.

unsafe abortion
"A procedure for terminating unwanted pregnancy either by persons lacking the necessary skills or in an environment lacking minimal medical standards or both" (WHO).

vital statistics
Data collected from continuous or periodic recording or registration of all "vital events", such as births, deaths, marriages and divorces.

women of reproductive age (or women of childbearing age)
Refers to all women aged 15 to 49 years (WHO).