Environmental contributors to preterm birth- implications for practice and policy

Preterm birth is an intractable public health problem, affecting more than 500,000 infants per year in the United States. Long term sequelae of preterm birth include intellectual disabilities, cerebral palsy, vision and hearing loss, and respiratory and digestive problems. The annual societal economic burden associated with preterm birth in the U.S. was estimated at $26.2 billion in 2005. The etiology of preterm birth is complex, but is believed to involve a combination of maternal health, genetic and environmental factors. Traditional models of environmental influences examine the effects of nutrition, substance abuse, psychosocial stress and social support on the duration of gestation. A mounting body of research links environmental contaminants to preterm birth.

This presentation will examine the growing body of evidence associating environmental toxicants with preterm birth. For example, epidemiological studies link perflourinated chemicals, brominated flame retardants, plastic additives called phthalates, pesticides, and components of air pollution to shortened gestation. Animal models provide insight into the biological mechanisms that may be responsible for this effect. An inflammatory response in the female reproductive tract appears to be a major factor.

Interventions that minimize exposures to toxicants during pregnancy are a valuable public health strategy in reducing preterm births. Potential sources of environmental exposures will be reviewed, along with clinical screening tools and resources for patient education on risk reduction. Because many exposures are not avoidable on an individual basis, changes in health policy maybe warranted. Policy implications based on the current body of reproductive environmental health research will be discussed.