Congenital Malformations Registry - 1996 Report

Section VI

Current Topics

The National Centers for Birth Defects Research and Prevention

Birth defects are the leading cause of infant death in the United States, accounting for more than 20% of all infant deaths. They also contribute substantially to illness, long-term disability, and in some cases, an earlier death.

One of the first steps in preventing birth defects is identifying their causes; however, the causes of about 40-60% of all birth defects are still unknown. One reason is that it is difficult to conduct studies with enough cases of specific birth defects to identify their causes. Overcoming this difficulty requires a concerted national effort to determine what environmental, genetic, occupational, nutritional, and behavioral factors cause or contribute to birth defects.

To help reduce birth defects among U.S. babies, in 1996, Congress directed the Centers for Disease Control and Prevention (CDC) to establish the Centers of Excellence for Birth Defects Research and Prevention. This was formalized with passage of the Birth Defects Prevention Act of 1998 (Public Law 105-168). This Act authorized CDC to (1) collect, analyze, and make available data on birth defects; (2) operate regional centers that will conduct applied epidemiological research for the prevention of birth defects; and (3) provide the public with information on preventing birth defects. In1996, the New York Center was established as part of the New York State Department of Health’s Congenital Malformations Registry. Currently, CDC has established centers in 7 states awarding each center $800,000 per year for 5 years. The states are Arkansas, California, Iowa, Massachusetts, New Jersey, New York and Texas.

The Centers are all participating in the National Birth Defects Prevention Study, conducting center-specific research projects, and expanding and improving birth defect surveillance systems in their states. The research done by these Centers will increase understanding, potentially dramatically, of the causes of birth defects and will provide information for developing effective birth defects prevention activities.

National Birth Defects Prevention Study

The major research effort of all of the Centers is the National Birth Defects Prevention Study (NBDPS). The NBDPS is one of the largest case-control studies of the causes of birth defects ever conducted. This study will provide information about potential causes of birth defects and a mechanism for identifying new factors or substances in the environment that are harmful to developing babies.

The study has three components. First, through existing surveillance systems, the Centers are identifying and collecting information on infants who have at least one of 30 major birth defects for which there are unknown or uncertain causes. The cases are reviewed and classified by clinical geneticists and entered into a central clinical database. The Centers also collect data on selected infants who do not have any major malformations ("controls") and compare the data to that collected for infants with birth defects ("cases"). Second, the infants’ mothers are interviewed using a computer-assisted telephone interview (CATI). The interview includes questions about pregnancy and medical histories, lifestyle habits, and possible exposure of the mother or her fetus to harmful substances in the mother’s workplace. The data from all sites, 16,000 interviews over a 5-year span, will be pooled electronically so that researchers can analyze the data to identify an association between risk factors and birth defects. Third, the Centers are collecting cheek cells samples from the infants and their parents. Researchers will study the DNA (genetic material) from these cheek cells to find out genetic susceptibilities to birth defects. Some of the DNA will be stored in a specimen bank at the CDC for future research as new hypotheses and improved technology emerge.

30 Major Birth Defects by Organ System Affected
Studied in the National Birth Defects Prevention Study

A birth defect is considered major if it affects survival, requires substantial medical care, or results in marked physiological or psychological impairment (handicap).

Cardiovascular: Conotruncal heart defects, Flow related heart defects, Cell death heart defects, Atrioventricular canal defects, Single ventricle, Anomalous pulmonary venous return, Ventrical septal defect - NOS, Heterotaxy

Central Nervous System: Neural tube defects, Hydrocephaly, Holoprosencephaly, Dandy-Walker malformation

Eye: Anophthalmia, Microphthalmia

Ear: Anotia, Microtia

Gastrointestinal: Esophageal atresia and Tracheoesophageal fistula, Intestinal atresia, Biliary atresia

Genitourinary: Bladder exstrophy, Renal agenesis - bilateral, Hypospadias-2nd or 3rd degree

Musculoskeletal: Diaphragmatic hernia, Gastroschisis, Omphalocele, Limb deficiency, Craniosynostosis, Cloacal exstrophy, Sacral agenesis/caudal regression

Orofacial: Choanal atresia, Orofacial clefts

Other: Amniotic band sequence

New York State Department of Health
Center for Birth Defects Research and Prevention

The New York Center's mission is to refine existing surveillance activities and to develop partnerships to conduct birth defect prevention research. The Center draws its cases for the National Birth Defects Prevention study from two areas (1) eight counties in western New York that are also the focus of fetal alcohol syndrome surveillance, and (2) the lower Hudson Valley Region, which covers seven counties and is also the focus of neural tube defect surveillance. Researchers from New York State Department of Health's Wadsworth Center work closely with CMR staff.

The Center's area of special expertise including Geographic Information Systems, occupational exposure studies, environmental epidemiology, folate metabolism, mouse genetics, socioeconomic status and disease.

Key Center-Specific Projects

  • Studying gene-environment interactions involved in oral clefts
  • Studying the relationship between socioeconomic status and malformations
  • Studying folate derivatives and other factors involved in neural tube defects
  • Studying caffeine and selected birth defects
  • Examining quality of care issues for children with birth defects
  • Studying the relationship between congenital malformations and susceptibility to cancer
  • Studying asthma medication and congenital heart malformations and other selected birth defects
  • Studying maternal illnesses, such as hypertension and thyroid disease, and selected birth defects
  • Studying the effects in the offspring of maternal HIV medication
  • Establishing a Hemangioma Registry
  • Supporting the development of Clinical Guidelines for the Work-up of Children with malformations
  • Studying mutations in androgen receptor genes and hypospadias
  • Active surveillance of neural tube defects and fetal alcohol syndrome
  • Collaborating with other Centers on studies of pesticide exposure, occupational exposure and drinking water

Center’s Partners

  • Northern-Metro Chapter of March of Dimes
  • Pediatric Otolaryngology Department, Children’s Hospital of Buffalo
  • Regional Medical Genetics Center, Westchester
  • Division of Genetics, Children’s Hospital of Buffalo
  • Western New York Teratology Information Service
  • Department of Genetics, University of Rochester