Daily News Archive
From January 7, 2002

Scientists Seek Cause of Premature Births

As premature births have steadily increased, researchers are trying to determine the cause. Scientists and the March of Dimes are looking to Congress to direct the National Institute of Environmental Health Sciences (NIEHS) or the Environmental Protection Agency to spend more research dollars on this issue.

During a recent meeting sponsored by the Institute of Medicine (IOM), speakers presented evidence that industrial chemicals, pesticides, and air pollutants could be contributors. However, they stated that more studies are needed to determine the links of environmental chemicals to premature births.

Since the 1980s, there has been a 23 percent increase in premature births in the United States. In 1999, 11.8 percent of all babies born in the United States (440,000 infants) were born prematurely, which is before the end of the 37th week of gestation. In 1981, 9.4 percent of live births were premature. While part of the increase can be attributed to women now becoming pregnant at older ages and to fertility treatments that cause multiple births, rates also rose among women under age 35.

For example, an epidemiological study implicates arsenic in drinking water as causing premature births. However, Matthew P. Longnecker, an epidemiologist with NIEHS, says that levels in the arsenic study were twice as high as the most highly contaminated areas in the United States. Occupational studies also associated preterm births with exposures to pesticides, but only general exposure data were available.

According to Carole A. Kimmel, senior scientist at EPA's National Center for Environmental Assessment, current federal testing guidelines for toxic substances are often poorly designed for measuring chemicals' effects on the length of gestation. Clearly, more data are needed. IOM's report of their meeting on environmental causes of premature births will be sent to Congress early this year.

Contact Children's Environmental Health Network at www.checnet.org for more information about this issue.