Reproductive and Birth Outcomes
Reproductive and Birth Outcomes Indicators
Reproductive and birth outcomes may be different across geographic areas due to access to care, level of care and a woman's personal and behavioral characteristics, and environmental exposures. Data on the Tracking Network are provided by CDC's National Vital Statistics System from local and state vital statistics systems (birth, death, and fetal death records) and the U.S. Census Bureau.
The Tracking Network collects data and information on the following reproductive and birth outcome indicators.
This indicator looks at the total fertility rate (TFR). The TFR is the number of births that a hypothetical group of 1,000 women would have if they experienced throughout their childbearing years. This indicator uses age-specific birth rates, which controls for variation in birth rates due to age and difference in the average age of all women between states and counties. This indicator provides background information about how fertility varies geographically and over time. These data are available at the state and county level.
This indicator tracks the occurrence of premature single births. This indicator can be used to identify trends and patterns in premature births. It can also be used to evaluate the effectiveness of public health actions and interventions for preventing prematurity. These data are available at the state and county level.
This indicator tracks the occurrence of low birth weight (LBW) among full-term, single birth newborns. It can be used to track the perinatal health because LBW is an important predictor of perinatal morbidity and mortality. It can also be used to evaluate the effectiveness of public health actions and interventions for preventing LBW. Baseline data can be used to monitor changes or trends. These data are available at the state and county (or census tract at state level where appropriate) level. .
This indicator helps to identify populations with higher rates of infant mortality for all infants (under 1 year of age), neonates (infants younger than 28 days), perinates (infants at 28 weeks gestation to younger than 7 days old), and post-neonates (infants aged 28 days to < 1 year). These data can be used to assist with targeting outreach intervention activities. It can also be used to improve our understanding of geographic variation, time trends, and demographic patterns of infant death. These data are available at the state and county level.
This indicator can be used to monitor the proportion of males to females. Baseline data can be used to determine if the proportion of males is changing over time. These data are available at the state and county level.
- Reproductive and birth outcomes are influenced by many factors, not just environmental exposures.
- Infant mortality, low birthweight, prematurity and sex ratio data are based on maternal residence at time of birth. This may be different than maternal residence during pregnancy and infant residence during the first year of life which affects our ability to connect these indicators to possible environmental exposures.
- For the prematurity indicator, there are some uncertainties associated with gestational age estimates. The interval between the first day of the mother's last normal menstrual period and the day of birth is one method used to determine the gestational age of the newborn. However, this measurement is subject to error. Changes in reporting of the gestational age over time may affect trends in preterm birth rates, especially by race. These reporting problems may occur more frequently among some group and among births with shorter gestations.
- Multiple births are not included in the sex ratio, low birthweight, and prematurity indicators. They are included in the infant mortality and fertility indicators.