EXPOSURE TO AMMONIA IN PREGNANCY

Ammonia is a colourless gas with a strong characteristic odour that allows its detection at low levels. Ammonia compounds are used in fertilisers, plastics, synthetic fibres, dyes, explosives, pharmaceuticals, and are a major component of many common household cleaning products.

There are no published studies on the effects of exposure to ammonia in human pregnancy. As with all chemicals, unnecessary exposure to ammonia 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 ammonia poses a hazard.

Following acute ammonia 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 ammonia, 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.

Exposure to ammonia at any stage of pregnancy would not usually be regarded as medical grounds for termination of pregnancy. Where maternal toxicity is evident, additional fetal monitoring may be warranted, particularly if exposure is associated with maternal hypoxia. Discussion with UKTIS is recommended in such cases. Other risk factors may also 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.