According to the CDC, approximately 120,000 babies in the United States are born each year with birth defects—one out of every 33 (Centers for Disease Control and Prevention [CDC], 2007). A birth defect is an abnormality of structure, function, or metabolism (body chemistry) present at birth that results in physical or mental disabilities or death. Several thousand different birth defects have been identified.  For the past 20 years, birth defects have been the leading cause of death in the first year of life (Martin, Kochanek, Strobino, Guyer, & MacDorman, 2003). Genetic and environmental factors, or a combination of these factors, can cause birth defects. However, the causes of about 70% of birth defects are unknown (CDC, 2007).

While some birth defects are inherited, many are caused by factors such as nutritional deficiencies, maternal alcohol or drug use, and exposure to environmental toxins. Several environmental contaminants cause birth defects when pregnant women are exposed to high concentrations, including mercury and polychlorinated biphenyls (PCBs); for example, fetal mercury poisoning can cause deafness and blindness, and fetal exposure to high levels of PCBs causes skin and nail abnormalities (Harada et al, 1999; Rogan, 1982). Epidemiological studies have demonstrated associations between birth defects and a number of prenatal exposures.  Multiple studies have linked women’s occupational exposure to organic solvents to increased risk of birth defects such as heart defects and cleft lip and palate (McMartin, Chu, Kopecky, Einarson, & Koren, 1998). Studies evaluating the role of pesticides have found an association between maternal and paternal exposure to pesticides and increased risk of offspring having birth defects (U.S. EPA, 2003). A 2002 study by Ritz et al. found links between certain heart-related birth defects and ambient air pollution. 

Cost Estimates: This study estimates the costs of structural birth defects (i.e., malformed limbs, heart problems, facial abnormalities) attributable to environmental contaminants in two ways.  The first estimate is based on a CDC publication on the national costs of a list of eighteen defects, and the second estimate is based on the total costs of a list of twelve birth defects developed by the Trust for America’s Health. Both estimates are based on the same EAFR and best estimate. 

A 1995 CDC study estimated the annual cost of 18 birth defects  at $8 billion in 1992 dollars for a single year’s birth cohort (Waitzman, Romano, Scheffler, & Harris, 1995).  Direct health care costs were estimated to be $2.1 billion and indirect costs were estimated to be $5.9 billion.  Indirect costs include developmental services, special education and lost future income and reduced earning potential due to the disorders.  Inflated to 2007 dollars the total cost rises to $12.0 billion.  In order to avoid double-counting costs for cerebral palsy, which is already included in “neurobehavioral disorders” (the next section of this report), the cost for cerebral palsy is omitted here.  In addition, the costs for Down syndrome, a condition not attributable to environmental factors is deducted: 

($12.0 billion) – ($6.3 billion)  = $5.7 billion

The Trust for America’s Health estimated that in 2001 the lifetime costs associated with twelve selected birth defects  in a single year’s birth cohort in Oregon was $84 million (Trust for America’s Health, n.d.; Harris & Levy, 1997). This is equivalent to $99.7 million in 2007 dollars. While the direct and indirect costs are not given separately, this estimate includes costs of medical treatment, developmental services, special education and lost productivity resulting from the affected children’s death or disability.  This estimate does not included lost wages of family members caring for children with birth defects, psychosocial costs, or the effects of inflation on health care costs.  Deducting the costs for Down syndrome, a condition not attributable to environmental factors, the Trust for America’s Health’s total cost figure for Oregon is: 

($99.7 million)  - (22.4 million)  = $77.3 million

Environmentally-Attributable Fraction Range (EAFR) and Best Estimate:  A 1999 study estimated that 5-10% of all birth defects are associated with environmental and occupational exposures to chemicals during pregnancy (Smith, Corvalan, & Kjellstrom, 1999). A 2006 report from the World Health Organization estimated that 5% of all birth defects are attributable to environmental causes, with a range of 2-10% (Pruss-Ustun & Corvalan, 2006). Based on these two studies, we estimate an EAFR of 2-10% and use a conservative best estimate of 4% to calculate the cost of birth defects from environmental contaminants. 

Costs in Oregon
Following are two methods for calculating environmentally attributable birth defect costs in Oregon. The first is based on cost data from the CDC, and the second utilizes cost data from the Trust for America’s Health. Because Oregon-specific information on the incidence of birth defects is unavailable, we applied the Oregon proportion of annual U.S. births to the CDC’s and Trust for America’s Health annual cost estimates to arrive at an Oregon cost estimate.  This is the same methodology used by Davies and Haugh (2005) in the Washington study and Schuler et al. (2006) in the Minnesota study. 

i. CDC Study Estimate

These estimates of the yearly costs of birth defects in Oregon attributable to environmental contaminants are based on the following assumptions:

• There were 4,143,000 births in the U.S. in 2005 (Munson & Sutton, 2006);
• There were 45,905 births in Oregon in 2005, which is 1.1% of the national total; 
• The rate of birth defects in Oregon is comparable to national rates;
• CDC’s estimate of total annual costs for 16 of 18 birth defects in 2007 dollars is $5.7 billion; and
• A best estimate of 4% and an EAFR of 2-10%.
  

The annual costs of birth defects in Oregon = ($5.7 billion) * (0.011) = $62.7 million. 

Applying the EAFs of 0.02, 0.04, and 0.1 yielded the following results:

• EAF 0.02 = $1,254,000
• EAF 0.04 = $2,508,000
• EAF 0.10 = $6,270,000
  

Under these assumptions, the best estimate of the cost of birth defects in Oregon attributable to environmental contaminants is $2.5 million in 2007 dollars with a range of $1.3 to $6.3 million.

ii. 2001 Trust of America’s Health Estimate

These estimates of the yearly costs of birth defects in Oregon attributable to environmental contaminants are based on the following assumptions:

• The Trust for America’s Health’s estimate in Oregon for 11 of 12 birth defects in 2007 dollars: $77.3 million; and
• A best estimate of 4% and an EAFR of 2-10%.
  

Applying the EAFs of 0.02, 0.04, and 0.1 yielded the following results:

• EAF 0.02 = $1,546,000
• EAF 0.04 = $3,092,000
• EAF 0.10 = $7,730,000
  

Under these assumptions, the best estimate of the cost of birth defects in Oregon attributable to environmental contaminants is $3.1 million in 2007 dollars with a range of $1.5 to $7.7 million.

These two estimates, which are fairly similar, are likely to underestimate the actual costs of environment-related birth defects. Many birth defects that have been linked with exposure to environmental contaminants, such as genitourinary defects, are not included in either one of these two cost estimates. 

Averaging the best estimates, the environmentally attributable costs of birth defects in Oregon are estimated at $2.8 million per year, with a range of $1.3 to $7.7 million.

NEXT: Neurobehavioral Disorders