A new study has indicated that women must refrain from drinking chlorinated water during pregnancy as it could increase the risk of cleft palate and heart disease in their babies.
The study, conducted by a team of researchers led by Jouni Jaakkola from the Institute of Occupational and Environmental Medicine, University of Birmingham, UK, was based on an analysis of nearly 400,000 infants in Taiwan.
The boffins used statistical analyses to see if drinking tap water containing high, medium or low levels of chlorination by-products increased the risk of 11 common birth defects.
Though they could not find a direct link between the prevalence of any birth defect and the level of exposure, the analysis revealed that exposure to high levels of by-products substantially increased the risk of three common defects: ventricular septal defects (holes in the heart), cleft palate, and anencephalus (where neural development fails, resulting in the absence of a major portion of the brain, skull, and scalp).
These results were corroborated by additional analyses, using pooled data from a number of similar studies.
"The biological mechanism for how these disinfection by-products may cause defects are still unknown," says Jaakkola.
"However, our findings don't just add to the evidence that water chlorination may cause birth defects, but suggest that exposure to chlorination by-products may be responsible some specific and common defects.
"Whilst the benefits of water chlorination are quite evident, more research needs to be carried out to determine these side-effects"
The research is published in BioMed Central's open access journal Environmental Health.