Last update:
14-Mar-2010

Exposure to water disinfection by-products during pregnancy through ingestion, inhalation and dermal absorption has been associated with adverse pregnancy outcomes.

OBJECTIVE Studies in the current literature were reviewed that examined the association between exposure to water disinfection by-products during pregnancy and reproductive outcome.

METHOD Two individual researchers performed a Medline search for studies published from January 1974 to October 2008 using the index Mesh terms: "pregnancy outcome" or "low birth weight" or "very low birth weight" or "extremely low birth weight" or "fetal growth retardation" or "small for gestational age" and "trihalomethanes" or "acetic acids" or "trichloroacetic acid" or "water pollutants".

RESULTS The literature search identified 86 studies, 73 of which did not fulfill the pre-defined inclusion criteria, leaving 13 relevant studies. An additional 3 studies were included after examining the cited references of the papers. Finally included in the review were 10 retrospective cohort studies, 4 case-control studies, 1 cohort and 1 cross-sectional study. Six of 10 studies evaluating exposure to disinfection by-products and small for gestational age found a statistically significant correlation. Of 10 studies examining low birth weight 5 found a statistically significant correlation.

CONCLUSIONS �he current evidence reveals that exposure to disinfection by-products in drinking water is not associated with a high risk of adverse reproductive outcome. However the fact that this exposure affects a large part of the population reveals the importance of further research in this field.

Key words: Intrauterine growth retardation, Low birth weight, Pregnancy, Water disinfection by-products, Water pollutants.