Birth Defect Surveillance Data from Selected
1989 - 1996
This year, 29 states, in which nearly 60%
of U.S. births occur, have contributed data to this report by
the National Birth Defects
Prevention Network (NBDPN). As with the previous report (NBDPN, 97),
the data are presented as counts and rates for 47 specific birth
defects. The data are presented for the period 1989 through 1995
and for 1996. Some states did not have data for all of the years
included in this report, and there were differences among states
in the way that data on race and maternal age were reported. These
differences are explained as notes at the end of each table.
State birth defect surveillance programs vary considerably in
their case ascertainment methodology, their birth defect case definitions,
and their inclusion of stillbirths and pregnancy terminations in
their counts of birth defect occurrences. Some of the differences
among state programs are highlighted in the program
descriptions. The way that state programs report birth defect
data also varies and is reflected in the state data tables that
follow. Although the definitions for each birth defect category
included here were standardized as much as possible, states use
different systems to code their data (e.g., ICD-9-CM versus CDC/BPA),
resulting in slight variations in what they include or exclude
in each birth defect category. The codes for each of the birth
defect categories used in this report can be found in appendix
A. Some states do not count possible/probable birth defects
(conditions noted in a medical chart as possible birth defects
and needing to be ruled out), while other states include these
as cases. Because of the coding systems used, a few states cannot
differentiate possible diagnoses from confirmed diagnoses.
Because of these differences, the state birth defect data are
not combined to give overall rates for the country. It is possible,
however, to look at variation in rates within states and changes
in the rates of specific defects over time.
The National Birth Defects Prevention Network would like to thank
the State programs that submitted data for this report and the
following individuals at the Centers for Disease Control and Prevention
who compiled, cleaned, and formatted the data: Erik Ciccarone,
Cara Mai, and Igor Filyushkin.
National Birth Defects Prevention Network (NBDPD). 1997. Congenital
malformations surveillance report. Teratology 56(1/2):115-175.