MEPHT Data Set - Birth Defects

A birth defect is an abnormality of structure, function, or metabolism (body chemistry) present at birth that results in physical or mental disabilities or, sometimes, even death.

Data Considerations

When reviewing and interpreting birth defects data, it is important to take into consideration the following:

• Prevalence estimates are based on the residential location of the mother at the time of the child’s diagnosis.
• Defects related to early fetal deaths (gestational age < 20 weeks) and/or terminations are not included in prevalence estimates. Furthermore, defects that are not diagnosed at birth, that do not need hospitalization or that are diagnosed after age one may be underreported.
• When looking at a smaller geographic area, such as a county, cell suppression rules may be applied to protect the privacy of a child with a birth defect and their family.
• Counts and prevalence estimates may differ slightly from those contained in other publications. These differences may be due to file updates, differences in calculation methods (such as grouping ages differently or rounding off numbers at different points in calculations), and updates or differences in population estimates.

For additional information, please read the FAQ.

Data details

Footnotes

1. Data obtained from state and local birth defects surveillance programs through state and local Environmental Health Tracking Programs. States without data shown here may have data available through the state health department.

2. Only some states collect birth defects data. Among the states that do collect birth defects data, collection and ascertainment methods vary by state. Thus, calculating national rates using these data or making interstate comparisons is not recommended. Information about methods used by state is available in the metadata records.

3. Data do not include birth defects among still births or terminations.

4. Data are classified by mother's residence at the time of birth which may or may not be the same as the mother's residence at the time of conception.

5. Non-zero counts less than 6 for over a 5 year period (and corresponding rates) have been suppressed to protect confidentiality.

6. 'No Events' means county/state has zero live births for selected time period.

Blanks or Missing Data

Blanks or missing data within the maps, tables, and charts may be due to one of the following reasons: (1) data were not collected, (2) data were collected but were not provided to CDC, or (3) data were incomplete or did not meet data quality standards.

Data Differences

Data presented on CDC's Tracking Network may differ from data that are presented on state or city tracking networks, state or city health department websites, and other source websites for the same measures. The differences may occur for many reasons, such as use of different population estimates, differences in processes and timing for updating data, or differences in how a measure is defined for environmental public health tracking purposes. Consult the indicators and measures descriptions and metadata that are provided on this site for more information.

Indicator

For more information, refer to the documentation available through the Indicator and Data Link.

How should this data set be cited?

Suggested Citation

Centers for Disease Control and Prevention. Environmental Public Health Tracking Network. Birth Defects Prevalence.

Why was the data set created?

Purpose

• Evaluate changes in the distribution of birth defects in the general population by place (e.g., state or county of residence) and time
• Evaluate the prevalence of birth defects by maternal age, maternal race/ethnicity, or infant sex
• Target interventions and activities aimed at preventing birth defects in specific populations and communities.
• Help allocate resources and services for affected babies and families

How was the data set created?

Derivation of measure

1. Number of birth defect cases among live births over a 5 year period divided by 5
2. Number of birth defect cases among live births divided by total live births over a 5 year period, multiplied by 10,000

What are the limitations of the data set?

• Not all states have birth defects monitoring programs. Among those that do, not all submit data for every year, county, or defect. This can make it difficult to calculate and compare spatial and temporal trends.
• Variability in the birth defects monitoring methodology among states means that there are limitations to combining, comparing, or contrasting birth defects statistics for national purposes. The three common case finding methods used by states to collect birth defects data are active, passive with confirmation, and passive. The method that a program uses depends on legislation in the state, funding for the program, staff capacity, community input, and partners’ engagement.¹⁴ Active case finding methods are usually considered complete and confirmed, but the approach is resource intensive.³ For more information on these types of data collection methods, please refer to the following documentation: https://www.nbdpn.org/docs/SGSC_-_Ch6_Case_Ascertainment_Methods_-_final_draft_3-2015_2016DEC14.pdf
• Some birth defects may be underreported since not all defects are present at birth. Also, not all birth defect programs ascertain cases up to age one year, although most of them do. Underreporting the number of birth defects can underestimate the risk in the population.
• Classification as isolated, multiple, or syndromic poses challenges for coding birth defects and ensuring cases are not over-represented.
• Address data reflects where the mother lived at delivery. This residence may not reflect true exposure at conception or during pregnancy if the mother moved during pregnancy.

How should these data be used?

Use Constraints

Ideally, incidence rates would be used instead of birth prevalence to measure birth defects occurrence. The incidence rate of a disease is defined as the number of new cases of a disease that occur during a specified period of time in a population at risk for developing the disease. Prevalence is defined as the number of affected persons present in the population at a specific time divided by the number of persons in the population at that time16. However, incidence cannot be calculated because both of the following are unknown: the number of conceptions and the number of cases “lost” through spontaneous abortions (as well as terminations and later fetal losses, depending on the sources of ascertainment for the specific birth defects monitoring system). Birth prevalence is the only appropriate measure that can be reported for birth defects occurrence.

How can someone get a copy of the queried data set?

Your queried dataset is available for download by clicking the export icon from within your query screen. The resulting .zip file will include your data in a .csv format as well as supporting information about the data.
 

Questions

If you have questions about this dataset, the tracking portal or the National Environmental Public Health Tracking Network please contact us at [e-mail]