Scientists link exposure to solvents and congenital malformations

Vincent Gallon

28 September 2009

Results of a study conducted by French scientists on a group of 3421 pregnant women provides further evidence of an association between exposure to solvents during pregnancy and the risk of major foetal malformations.

Several studies have suggested that the exposure to solvents would be particularly dangerous for pregnant women with a possible link with congenital malformations.

French scientists from the National institute of health and medical research (Institut national de la santé et de la recherché médicale - Inserm) have studied a prospective population-based cohort, specifically designed to study the impact of maternal exposure to solvents on the risk of congenital malformations.

The study began in 2002 in three districts of Brittany (France). In practice, 3421 pregnant women were recruited until the end of 2005 by physicians before 19 weeks of gestation and followed through birth. Information on pregnancy outcomes was obtained from the hospital. Occupational exposure to solvents at the beginning of pregnancy was assessed from the women’s self-reported occupational exposures at inclusion and from a job-exposure matrix (JEM). Sociodemographic characteristics, lifestyle factors, medical history, diseases during pregnancy were obtained at inclusion and from hospital records.

Analyses were restricted to the 3005 working women. Logistic regressions were used to adjust for potential confounders and 30.2% of them declared regular exposure to at least one product that may contain solvents. 21.3% of the working women were classified at least in the medium exposure category using the JEM. Occupations mainly classified as exposed by both assessment methods were hairdressers, nurses’ aides, nurses, cleaning women and chemists/biologists.

Significant associations were found between major congenital malformations and maternal occupational exposure to solvents. A significant dose-response trend was observed with several subgroups of major malformations (oral clefts, urinary malformations and male genital malformations) associated with maternal exposure to solvents.

The authors of the study say it is now necessary to identify the characteristics of the solvents related to these foetal anomalies as well as any other possible exposure in the concerned occupations. Complementary analyses are currently conducted on urine samples collected at the beginning of the gestation.

The study was published in Occupational and Environmental Medicine, an international peer reviewed journal.