According to a recently published study, drinking chlorine-treated tap water during pregnancy may increase the risk of having children with heart problems, cleft palate or major brain defects.

A research team led by Jouni Jaakkola from the Institute of Occupational and Environmental Medicine, University of Birmingham, UK, gathered data on almost 400,000 infants born in Taiwan. The researchers 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.

Although the researchers found no direct link between the prevalence of any birth defect and the level of exposure, their calculations 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).

This is making me nervous. I've been drinking predominantly tap water (yes, chlorinated, but I don't know the exact levels) all throughout my pregnancy!