The Tracking Network has data for many birth defects, (listed on the box to the right). For each birth defect indicator, there are two different measures:

• Average annual number of cases among live births over a 5-year period.
• Prevalence per 10,000 live births over a 5-year period.

On the Tracking Network, birth defects are reported as prevalence. Prevalence measures the number of birth defects occurring in a population and is the best way to report information about birth defects. This measure can be used to track the number of birth defects within a state. Read More about the Birth Defects Indicators.

In order to further refine the data being displayed, some advanced options are available. Users can filter results by:

• Infant gender
• Maternal age group
• Maternal race/ethnicity

Birth defect data are available at the county level. However, the Tracking Network does not have data for all states. And for some states, only certain counties have data. In addition, some states have more years of data available than others.