Birth Outcome Metadata: Mortality


Linked birth and death certificate data are used to calculate mortality (infant, neonatal, perinatal, and post neonatal) measures. Linked birth and death certificate data are from the Maine CDC, Office of Data, Research, and Vital Statistics (ODRVS).

Dates Available:

2000 – 2019

Geographic Resolution:

State, Public Health District, County


The Maine EPHT program receives birth and death certificate data annually from ODRVS. Infant, neonatal, perinatal, and post neonatal mortality measures among Maine residents are analyzed, stratified by year of death, infant sex, and geographic resolution.

The dataset contains the following measures:

1. Infant mortality rate per 1,000 live births
2. Neonatal mortality rate per 1,000 live births
3. Perinatal mortality rate per 1,000 live births
4. Post neonatal mortality rate per 1,000 live births
5. Number of infant deaths
6. Number of neonatal deaths
7. Number of perinatal deaths
8. Number of post neonatal deaths


This data set supports efforts to improve public health in Maine and contributes to the U.S. CDC’s National Environmental Public Health Tracking (EPHT) Network. A key activity of participants in this network is to track and make available environmental health measures on state and national data portals. Measures derived from the data set described here can be used to compare the individual measure mortality rates across the state, between groups of people, over time, and in relation to risk factors, exposures, and health outcomes.

The Maine Tracking Network, a member of the National EPHT Network, connects communities, public health professionals, policy makers, state agencies, and others to the data they need to monitor public health, respond to health concerns, prioritize resources for public health action, and evaluate prevention activities. Maine tracks certain health effects, exposures, and environmental hazards that have known relationships, as well as some health effects and environmental hazards that have suspected relationships. By making health and environmental data available through the Maine Tracking Network, more people have access to data they need to think critically and hypothesize about health outcomes and their relationships to conditions in the environment.

Supplemental Information:

The measure definitions are:

  • Infant mortality: The number of infant deaths occurring at less than 1 year of age in a given year, divided by the number of live births in the same year.
  • Neonatal mortality: The number of infant deaths occurring at less than 28 days of age in a given year, divided by the number of live births in the same year.
  • Perinatal mortality: The number of fetal deaths of infants occurring at 28 or more weeks of gestation plus infant deaths occurring at less than 7 days of age, in a given year, divided by the number of live births in the same year.
  • Post Neonatal mortality: The number of infant deaths occurring from 28 days up to 1 year of age in a given year, divided by the number of live births in the same year.

Geographic location is based on residence at time of death (for infant death numerator), and maternal residence at time of birth (for birth population denominator).

Restricting infant mortality to deaths that occur during the perinatal, neonatal, or post neonatal period may limit the range of causes applicable to overall infant mortality. In addition, it may be more likely that the deaths of infants who live in reasonable proximity to where they were born and who die between 7 and 28 days after birth can be attributed to environmental exposures, since more is known about the place in which they may have been exposed. Specifically, exclusion of infants who die within 28 days of birth from these measures might reduce etiologic variability due to difference in early prenatal care and other non-environmental factors likely to influence neonatal survival. Data on the location of death relative to the residence at time of birth is not provided.

Entity and Attribute Overview:

The dataset includes: year of death, geographic location, infant sex, number, rate and 95% confidence intervals.

Data Limitations:

  • There are uncertainties associated with the gestational age estimates that are used in some of the birth outcome analyses. In Maine, a clinical estimate of gestational age is recorded on the birth certificate, and this is used for gestational age estimates. Not all states include a clinician estimate and must use only information on the interval between the first day of the mother’s last normal menstrual period (LMP) and the day of birth to determine gestational age. Therefore there are differences in how gestational age is calculated across states.
  • Adoptive records may not have correct birth mother demographic information. It is possible that a birth record may arrive at the vital records with the birth mother’s demographic information only to be amended with the demographic characteristics of the adoptive mother.
  • Although there is universal reporting of live births and infant deaths in the U.S., some births/deaths may be excluded because of the difficulty in distinguishing a death shortly after birth as a live birth; a death soon after birth might be reported as a fetal death rather than as a live birth and infant death.
  • Data on fetal death certificates may not provide all the information that could be collected.  Variables used for environmental tracking (i.e. mother’s place of residence) are typically included, though missing data sometimes occurs.
  • The most important information used to link birth outcomes to environmental exposures is the place of residence during pregnancy and the first year of life. The location information used refers to the mother's place of residence at birth, which does not always represent where the mother lived during pregnancy or where the infant lived.

Access Constraints:

Publicly available data are suppressed in accordance with the Maine CDC Privacy Policy to protect confidentiality.

More Information:

Suggested Citation for Data Displays:

Maine Center for Disease Control and Prevention, Maine Tracking Network. Birth Outcomes Metadata: Mortality. Available online: Accessed on [date accessed].