There are no published studies on the effects of exposure to chlorine in human pregnancy. Increased incidences of urinary tract defects, preterm delivery, and low birth weight have been reported following environmental exposure to water chlorination by-products, however data are inconclusive and their relevance to exposure to chlorine gas is uncertain.
As with all chemicals, unnecessary exposure to chlorine during pregnancy should be avoided due to a lack of information on safety. Where exposure is expected to occur, it should be well within the recommended exposure limits and not associated with toxic symptoms. There is currently no indication that normal use of household products containing chlorine poses a hazard.
Following acute chlorine exposure in a pregnant patient, maternal toxicity is likely to be a major determinant of fetal risk. However, due to a lack of data relating to the teratogenicity of chlorine, it is not currently possible to state that an absence of maternal toxicity excludes the possibility of adverse effects on the developing fetus. Treatment should be as for the non-pregnant patient and is largely supportive.
Exposure to chlorine at any stage of pregnancy would not usually be regarded as medical grounds for termination of pregnancy or any additional fetal monitoring. However, other risk factors may be present in individual cases which may independently increase the risk of adverse pregnancy outcome. Clinicians are reminded of the importance of consideration of such factors when performing case-specific risk assessments.