Birth data are derived from a subset of variables collected on the Texas Certificate of Live Birth. A new Certificate of Birth was introduced in Texas in 2005. The process involved in this revision, as well as details of what was revised, can be found at http://www.cdc.gov/nchs/vital_certs_rev.htm. There were several changes in the certificate that may affect comparisons with data for 2004 and earlier. A new birth module for 2005 and onward was added to Texas Health Data to reflect those changes. Care is recommended when making comparisons with pre-2005 data.
Tables of birth statistics can be created for many outcomes or risk factors by county of residence of the mother. The categories include four or more prior births, no prenatal care, prenatal care began in first trimester, smoking during pregnancy, cesarean section, vaginal birth after cesarean, spacing less than 18 months apart, low birth weight, very low birth weight, and premature births.
Note: For years prior to 2004, there are some differences between the number of premature births reported here, and those supplied by the National Center for Health Statistics (NCHS). Numbers and rates for premature births are based on calculated length of gestation. In the Texas vital statistics database that is the source for birth data prior to 2004, gestation periods are measured in whole weeks, so that the actual time of gestation is rounded. The result of this rounding is that some of those gestation periods that fall between 36 and 37 weeks are rounded up to 37 and such births are therefore not reflected in prematurity counts. However, since the exact length of the pregnancy is less than 37 weeks, these births would be designated as premature in a system, like that of NCHS, that does not round the data. Counts and rates of prematurity obtained from the Texas vital statistics database are underestimated, compared with NCHS data for years prior to 2004. For this reason trends in prematurity rates that span the 2003 - 2004 time periods may show some discontinuity and should be interpreted with care.
Output tables can be displayed as frequencies only, frequencies and percents by column, frequencies and percents by row, or percents by cell. When percents by cell is chosen, the denominator for the measure is the number of births for which the specific measure is recorded on the birth certificate.
Row variables for the output table include year, age group, race/ethnicity,
marital status, selected groups of counties, and outcomes. Column
variables for the output table include year, age group, race/ethnicity,
and marital status. Additionally, tables can be restricted to one
level of those variables that have not been selected as row or column variables
or to groups of counties not selected as row or column variables.
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Last Updated December 20, 2011