Common Substances Abused During Pregnancy: Refers to the “sniffing” or “huffing” of aerosol drugs (e.g. airplane glue, cooking sprays, and computer keyboard cleaner) Most of these substances contain freon as a propellant and can lead to severe respiratory and cardiac irregularities. They have the same effect with alcohol abuse during pregnancy. Respiratory depression they cause can result to limit the fetal oxygen supply to a serious level.