Tracking Reproductive and Birth Outcomes

The Tracking Network obtains data for reproductive and birth outcomes from CDC's National Center for Health Statistics National Vital Statistics System and the U.S. Census Bureau. Vital statistics data are information about human life such as births and deaths.

Providing these data through the Tracking Network can improve surveillance methods by creating indicators that can be linked to environmental exposure or hazard data that are not being collected by existing surveillance systems.

The Tracking Network collects and displays data on the following reproductive and birth outcomes:

• Premature Births: When a baby is born before the 37^th completed week of pregnancy.
• Low Birthweight: Birth weight is the weight of the newborn measured immediately after birth. Birth weight of less than 5.5 pounds, or 2,500 grams, is considered low birth weight.
• Infant and Perinatal Mortality
  • Infant mortality: when an infant dies before he or she is 1 year old.
  • Perinatal mortality can have several different meanings:
  1. Death after the 28^th week of pregnancy, but before the 7^th day of age (perinatal)
  2. Death less than 28 days of age and fetal deaths of 20 weeks or more (neonatal)
  3. Death after 28 days of age but before 1 year old (post-neonatal).
• Fertility and Infertility:
  • Fertility: the ability to conceive children.
  • Infertility: not being able to get pregnant after one year of unprotected sex
• Sex Ratio:  the number of babies born male compared to the number of babies born female. The expected sex ratio at birth (male to female) is 105 boys born for every 100 girls.

Learn more about the exposure and risk factors for these reproductive and birth outcomes.