Congenital Malformations Registry - 1996 Report

Summary

The Congenital Malformations Registry Summary Report presents rates of congenital malformations occurring among the 520,587 children who were born alive to New York residents in 1996 and 1997. The children reported with a major congenital malformation represent 4.1% of live births. Males had a higher rate of major congenital malformations than females (4.9% versus 3.3%), and black children had a higher major malformation rate than white children (4.8% versus 4.0%). This information is provided through mandated reporting by hospitals and physicians.

Demographic characteristics of those children reported to the Congenital Malformations Registry (CMR), number of malformations and age at diagnosis are included in the report. Other sections present the distribution of anomalies by organ system; rates for selected malformations by race and sex and the most common malformations for each county in the state are also included.

This is the thirteenth report from the CMR. Reports are also available by request for the 1983 to 1995 birth cohorts. This report and the reports for 1994 and 1995 are also available on the Department of Health website. The statistics in this report are not comparable to reports before 1992. In 1992, the CMR began to use a new coding system that allows for greater detail in coding. For previous years, ICD-9 codes were used. Information from birth certificates was used to supplement or correct reported data. Birth certificate matching also helps eliminate duplicate cases reported under different names and nonresident births. Reports produced for 1989 to 1991 did not use birth certificate matching.

PROGRAM OVERVIEW
Background

Congenital malformations are the leading cause of infant mortality in the United States.1 They are the fifth leading cause of years of potential life lost and a major cause of morbidity and mortality throughout childhood.1,2 Twenty percent of infant deaths are attributed to congenital malformations,2 a percentage that has increased over time.1,2 Approximately 25% of pediatric hospital admissions and about one-third of the total number of pediatric hospital days are for congenital malformations of various types.3 Little is known about the causes of congenital malformations. Twenty percent may be due to a combination of heredity and other factors; 7.5% may be due to single gene mutations; 6% to chromosome abnormalities; and 5% to maternal illnesses, such as diabetes, infections or anticonvulsant drugs.4 Approximately 40% to 60% of congenital malformations are of unknown origin.4,5

Although radiation and rubella had been linked to birth defects, not until the thalidomide tragedy of the early 1960s was there a widespread interest in possible associations between congenital malformations and environmental agents. During the 1970s, interest continued to grow in birth defects and birth defects surveillance as a result of the growing recognition of the problems of toxic waste dumps such as Love Canal and accidents such as Three Mile Island and Seveso. In response, many states began to develop birth defects registries in order to have data for tracking trends in malformation rates.6,7 A birth defects registry also makes it possible to respond to public concerns about possible excess occurrence of malformations with timely, objective investigations. A birth defects registry can provide cases for traditional epidemiologic studies of specific congential malformations and provide information for the planning, provision and evaluation of health services.6,7

New York State
Congenital Malformations Registry

The New York State Department of Health Congenital Malformations Registry (CMR) is one of the largest statewide, population-based birth defects registries in the nation. The concept of the Congenital Malformations Registry arose out of recognition of the environment as a potential etiologic factor in the occurrence of congenital malformations. Health studies during the Love Canal crisis in 1978 to 1983 confirmed the inadequacies of relying on birth certificates to monitor and evaluate birth defects.

New York's Congenital Malformations Registry was established by enactment of Part 22 of the State Sanitary Code in 1981. Reporting to the registry began in October 1982. Hospitals and physicians are required to report children under two years of age diagnosed with a malformation. The majority of reports are sent by hospitals, primarily from their medical records departments. A small number are sent by individual physicians to verify diagnosis initially suspected in the hospital but confirmed on an outpatient basis, and to clarify nonspecific diagnosis reported by hospitals.

The Congenital Malformations Registry receives case reports on children diagnosed up to two years of age who were born or reside in New York State with a congenital malformation, chromosomal anomaly or persistent metabolic defect. For purposes of this registry and report, a congenital malformation is defined as any structural, functional or biochemical abnormality, determined genetically or induced during gestation and not due to birthing events.

Case reports are received on forms (see Appendix 1) provided by the Department of Health (DOH). Pertinent fields are coded and the narrative description of the malformation is converted to a code. The case report is matched to existing registry reports for possible duplicates. Data from reporting forms are entered on microcomputers and then transferred to the DOH mainframe for updating of the master files.

All information reported to the registry is held in strict confidence. Records and computer files are maintained in accordance with DOH regulations concerning data containing individual identifiers. Access to the data by anyone other than registry personnel is restricted and carefully monitored to ensure that confidentiality is maintained. Families of children reported to the registry are never contacted without prior consent of the DOH's Institutional Review Board and notification of the child's physician.

1996-1997 Report

This current report presents statistics for major anomalies only (see Appendix 2). This is in accordance with the practices of other state birth defects registries and allows comparison between New York State rates and rates in other states. Minor anomalies may cause problems in the determination of malformation rates because they are common and variably reported. They may not even be recorded in the medical chart.

The statistics in this report are not comparable to reports prior to 1992. The 1996-1997 report is based on birth certificate matched cases with resident live births from the vital records file used as the denominator. The available birth certificate fields are used to supplement or correct reported data. Birth certificate data are used to establish maternal residence at birth. Birth certificate matching helps eliminate duplicate cases reported under different names. Racial data are not comparable because race is defined by maternal race from the birth certificate. Using maternal race is a common practice among birth defects registries nationwide as the race of the father is poorly reported. In earlier years, race was defined by what was reported on the CMR form, which may differ from what is recorded on the birth certificate. In 1992, the registry began using a new coding system, the modified British Pediatric Association code (BPA). This coding scheme is used by a number of other congenital malformations registries and allows for greater specificity than does the ICD-9 system. Since 1992, the list of major malformations has been revised (see Appendix 4) changing the list of major malformations used in Sections I and II and the number of specific malformation prevalences in Section III.

CMR Birth Cohort reports are intended as a resource for programs providing primary, secondary and tertiary preventive health care and for public officials concerned with reducing overall mortality and morbidity. The first annual cohort included children born in 1983 and reported with a malformation diagnosed before their second birthday.9 This report describes children born in 1996-1997 and diagnosed before their second birthday. Reports are also available for the 1984 through 1995 birth cohorts.

Limitations

Care should be taken in the use of these data. Virtually all reports are abstracted from inpatient hospital records, since malformations diagnosed on an outpatient basis are not well reported. Accurate hospital clinical recognition of malformations depends on clinical acumen and interest. This is particularly true of conditions more difficult to diagnose, such as fetal alcohol syndrome. Consequently, identification of malformations may vary by area and by time. The abstracting of records requires well-trained medical records professionals who are fastidious in their reporting of such findings. Areas with hospitals that provide higher levels of care may have more thorough diagnoses and, thus, apparently higher rates. Similarly, areas with hospitals that report cases more completely will also appear to have higher rates. In regions with low numbers of births, small variations in incidence may produce large statistical fluctuations.

New York State Population

Based on population projections from the 1990 census, the 1997 population of New York State was about 18.6 million; more than 40% of the population lived in New York City. An additional 23% of the population lived in the six counties closest to New York City. In 1996-1997, there were 520,587 resident live births reported to the state's vital registration, 22% to black mothers, and 19.8% to Hispanic mothers. In accordance with the practices of other state birth defects registries, the race of the child is based on race of the mother only. Nearly 46.5% of live births were to New York City residents.

References

  1. Kochanek KD, Hudson BC. Advanced report of final mortality statistics, 1992. Monthly Vital Statistics Report 1995; 43(6 suppl.). Hyattsville (MD):National Center for Health Statistics, 1995.
  2. Centers for Disease Control. Contribution of birth defects to infant mortality - United States 1986. MMWR 1989; 38:633-635.
  3. Epstein CJ. Genetic disorders and birth defects. In: Pediatrics, Rudolph AM, Hoffman JIE, Axelrod S, eds. Norwalk: Appleton & Lange, 1987:209-210.
  4. Kalter IT, Warkany J. Congenital malformation etiologic factors and their role in prevention. Parts I and II. N Engl J Med 1983; 308:424-431, 491-497.
  5. Nelson K, Holmes LB. Malformations due to presumed spontaneous mutations in newborn infants. N Engl J Med 1989; 320:19-23.
  6. Holtzman NA, Khoury MJ. Monitoring for congenital malformations. Ann Rev Public Health 1986; 7:237-266.
  7. Lynberg MC, Edmonds LD. Surveillance of birth defects. In: Public Health Surveillance, W Halpern and E Baker, eds. Van Nostrand Reinhold, NY, 1992:157-176.
  8. Merlob P, Papier CM, Klingberg MA, Reisner SH. Incidence of congenital malformations in the newborn, particularly minor abnormalities. In: Marois, ed. Prevention of physical and mental congenital defects, Part C: Basic and medical sciences, education and future strategies. Proceedings of a conference of the Institut de la Vie. New York: Alan R. Liss, 1985: 51-53.
  9. New York State Department of Health. Congenital Malformations Registry Annual Report: 1983 Birth Cohort.