Is drinking chlorinated tap water safe during pregnancy?
In recent years, media reports have raised concerns about possible pregnancy risks from by-products of chlorinated drinking water. Chlorine is added to drinking water to kill disease-causing microbes. However, when chlorine combines with other materials in water, it forms chemical by-products, including trihalomethanes (THMs). The level of THMs and other chlorification by-products in water supplies varies, although the EPA regulates the maximum level permitted in water supplies. A 1998 California study suggested that women who consumed more than five glasses a day of cold tap water containing high levels of trihalomethanes had an increased risk of miscarriage(14). However, a more recent North Carolina study found little or no increased risk from these chemicals(15). Scientists continue to study the safety of these chemicals during pregnancy. Until we know more, pregnant women who are concerned about chlorination by-products may choose to drink bottled water. Drinking water also can bec
