About Birth Defects Data


This site provides data of the number and prevalence of children born with birth defects in New York State by region and by county. Users can view birth defects data by county or by individual birth defect.

Data Source/Contact info New York State Congenital Malformations Registry
Timeframe 2000-2014
Geographic Coverage New York State by Region and by County
Last Update November 2019

View by County

Users can view a map showing combined birth defects prevalence per 10,000 live births, and click on a county to view county-specific counts and prevalence for combined and individual birth defects.

View by Birth Defect

Users can select a birth defect and time period to view tables showing counts and prevalence of selected data by region and by county.

Interpreting Data

  • Data include the number of babies born with one or more of 49 major birth defects and the prevalence of birth defects by region, county, and by birth defect for the most recent three-year period.
  • The source of the data is the New York State Birth Defects (Congenital Malformations) Registry, which is an archive for case reports of children born or residing in New York State diagnosed before the age of two with any structural, functional or biochemical abnormality determined genetically or induced during gestation and not due to birthing events.
  • Hospitals and physicians throughout the state are required to report children with particular birth defects who have been diagnosed before the age of two.
  • Birth defect prevalence is calculated by dividing the number of babies born with a birth defect by the total number of live births in the same geographic region over the same timeframe. That value is then multiplied by 10,000. Prevalence measures can be used to compare birth defects between geographic areas.
  • Unstable prevalence is marked with the symbol Unstable rate on maps and on data tables when the prevalence is based on fewer than 12 birth defects. This means that slight changes in the number of a particular birth defect can dramatically change the prevalence, making it hard to identify meaningful differences in the underlying risk of the birth defect. Comparing unstable prevalence can lead to false conclusions about the risk of birth defects in different geographic areas or timeframes.
  • The New York State Congenital Malformations Registry(CMR) uses passive case-finding with follow-up efforts to confirm the information. Reporting of any child less than 2 years old with a birth defect is mandated by New York State Public Health Law.
  • It is difficult to make meaningful comparisons between New York State's data and those from other registries due to how registries classify a child with a birth defect, how registries find children with birth defects (active versus passive case finding), which defects are recorded in the registry, and which birth outcomes are included in the registry.
  • CMR prevalence estimates have increased in the last 10-15 years mainly due to improved reporting as a result of:
    -Between 2002 and 2006, the CMR switched to a web-based reporting system which increased reporting timeliness and completeness.
    -Beginning in about 2005, the CMR began an effort to identify birth defects diagnoses that were not previously reported by record linkage with the NYS hospital billing database. Hospitals were asked to report these cases, which has improved completeness of CMR data.