Proximity of residence to trichloroethylene‐emitting sites and increased risk of offspring congenital heart defects among older women

Abstract

Our findings suggest that maternal age and TCE exposure interact to increase CHD risk, although the mechanism by which this occurs is unknown. A prospective study is underway to confirm this finding.

Maternal age and prevalence of isolated congenital heart defects in an urban area of the United States

“…Some discrepancies between our study and previous reports regarding the association between maternal age and increased risk of selected CHD phenotypes might be due in part to differences in study populations, methods, and unaccounted confounding or effect modification [Correa-Villaseñor et al, 1994;Pradat et al, 2003;Reefhuis and Honein, 2004;McBride et al, 2005;Forrester and Merz, 2008]. For example, a case-control study designed to evaluate the effects of exposure to trichloroethylene (TCE) on the risk of CHDs found maternal age to be an effect modifier for the relationship between TCE and CHDs [Yauck et al, 2004]. So differences in exposure to possible effect modifiers among studies could potentially result in apparent null effects when in fact the level of association might differ across strata of the effect modifier of interest.…”

Trichloroethylene and dichloroethylene: A critical review of teratogenicity

“…Craniofacial/ conotruncal malformations have been associated with occupational benzene exposure, but not "other solvents" (Wennborg et al, 2005). The Milwaukee case-control study found a statistically significant association of CHD with 6 of 7 maternal characteristics evaluated (Yauck et al, 2004). The 7th characteristic, "TCE exposure" defined as residence within 1.3 miles of a site that reported an environmental release of TCE, was identical for case and control mothers (19% of each group was within that radius).…”

“…In the Milwaukee study, there was no direct evidence of exposure to TCE (Yauck et al, 2004). Instead, exposure was assumed if the maternal home address at the time of delivery was within a 1.3-mile radius from a point source that reported at least 1 TCE emission in the same calendar year as the 5th gestational week of that pregnancy.…”

“…Reference groups for birth defects were the Metropolitan Atlanta Congenital Defects Program (MACDP) and the California Birth Defects Monitoring Pro- TCE exposure is assumed on the basis of maternal home address at time of birth within 1.32 miles of a point source that reported releasing TCE to air, soil, or water in the year corresponding to the fifth month of gestation. Yauck et al (2004) gram (CBDMP). Outcomes among Woburn residents were also evaluated according to estimated extent of exposure to water from contaminated wells.…”

“…A case-control study of live births in Milwaukee from 1 January 1997 to 31 December 1999 was conducted specifically to investigate the hypothesis that TCE is a cardiac teratogen for humans (Yauck et al, 2004). CHD cases were identified from inpatient and outpatient records of the Children's Hospital of Wisconsin; infants diagnosed only with patent ductus arteriosis, persistent foramen ovale, or peripheral pulmonary stenosis were excluded.…”