Congenital Malformations Registry - Summary Report

Section VI: Current Topics

The National Centers for Birth Defects Research and Prevention

Background

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. That same year, the New York Center was established as part of the New York State Department of Health (NYSDOH) Congenital Malformations Registry. Currently there are centers in 9 states including New York.

The major research effort of the Centers is the National Birth Defects Prevention Study (NBDPS). The NBDPS is the largest study of birth defects causes ever undertaken in the United States. Researchers have gathered information from more than 36,000 participants and are using this information to look at key questions on potential causes of birth defects.

The study has three components. First, the Centers identify and collect information on infants who have at least one of 30 major birth defects. 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. Third, the Centers collect cheek cell 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

Topics Being Studied by The New York Center

  • Untreated hypertension, thyroid disease and asthma and risk to the mother and baby. Our studies of maternal illness and medication use can help women and physicians make informed decisions about medication use during pregnancy. A future study will look at risks associated with a medication used to treat tension headaches.
  • Effects of caffeine on the risk of various birth defects. A study that takes into account genetically determined differences in caffeine metabolism is being conducted.
  • Alcohol exposure during pregnancy. We are researching the effects of alcohol use on the risk of several birth defects.
  • Climate, air pollution and tap water use and birth defects. Since we are based in the Department of Health's Center for Environmental Health, we have access to resources and expertise that we will use to conduct studies of the effect of climate, air pollution and tap water use on birth defects.
  • Home and Occupational Pesticide Exposure (HOPE) Study. New York is a rural state and issues of pesticide exposure are of concern. We have developed a pilot study of home and occupational pesticide exposure on birth defects by collecting additional information from NBDPS participants on pesticide exposure.

NBDPS Research Publications by New York Center Staff

  • This study looked at a wide range of occupations and birth defects. We found that one or more birth defects occurred with greater frequency among mothers who worked as janitors/cleaners, scientists and electronic equipment operators. A detailed study to follow up on these findings is being planned.

  • Treatment with antihypertensive medication early in pregnancy was associated with increased risk of having an infant with specific congenital heart defects. Some increases in risk were also observed for treatment that began after the first trimester and for untreated hypertension. We concluded that antihypertensive medication use and/or the underlying hypertension might increase the risk of having an infant with specific congenital heart defects.

  • Consistent with previous studies, we found that maternal thyroid disease or thyroid medication use was associated with increased risk of hydrocephaly and hypospadias. We also observed associations with certain congenital heart defects and with anorectal atresia. As with other studies of medication use during pregnancy, additional research will be needed to find out whether it is the medical condition or particular medications that pose a risk to the fetus.

  • Use of antifungal drugs during early pregnancy was not strongly associated with the risk of most birth defects. We did find an increased risk for a particular congenital heart defect, hypoplastic left heart syndrome. Since previous studies have not looked at antifungal drug use and the risk of specific defects, additional research will be needed to investigate this finding.

  • We found an association between hypertension, antihypertensive medication use, and the risk of severe hypospadias, particularly when medication use began late in pregnancy. Because hypospadias occurs in early pregnancy, we suspect that the hypertension itself plays a role in the higher risk of hypospadias. We are conducting another study to look at individual types of medications and the risk of severe hypospadias.

  • We observed that mothers who used certain asthma medications during pregnancy had an excess risk of giving birth to an infant with gastroschisis, an abdominal wall defect. [Additional studies will be needed to find out whether the increased risk was because of the medications or because of the asthmatic condition.]

  • Our study found no evidence that moderate intake of caffeine during pregnancy increases the risk of congenital heart defects.