Carbon Monoxide Exposure During Pregnancy

Importance Carbon monoxide (CO) is the leading cause of poisoning in the United States and is associated with high maternal and fetal mortality rates. Given the nonspecific signs and symptoms of toxicity, cases may go unsuspected or attributed to other etiologies. As CO adversely affects both mother and fetus, it is important for practitioners to recognize and treat poisoning in a timely manner.Objective We seek to assist practitioners with understanding the physiology and recognizing the presentations of both acute and chronic CO poisoning, as well as provide information on diagnosis and treatment options. We also conducted a review of cases described in the literature during the past half century to show varying presentations and treatment methodologies.Evidence Acquisition A qualitative literature search was conducted using PubMed and Google Scholar for articles published between 1970 and 2014 that assessed cases of CO poisoning during pregnancy. Excluded studies were not in English or contained nonhuman subjects.Results Nineteen published reports of CO poisoning during pregnancy described in varying levels of detail were found in the literature from 1971 to 2010.Conclusions and Relevance Carbon monoxide poisoning requires a high degree of suspicion. Diagnosis is made based on initial history and physical evaluation and assessment of environmental CO levels; presenting carboxyhemoglobin levels may be poor indicators of severity of disease. Oxygen therapy should be initiated promptly in all possible cases with consideration of hyperbaric oxygen therapy in cases of significant maternal exposure. Treatment requires a longer duration for fetal CO elimination than in the nonpregnant patients. Importantly, practitioners should educate pregnant patients on prevention.Target Audience Obstetricians and gynecologists, family physiciansLearning Objectives After completing this activity, the learner will be better able to: describe the basic pathophysiology of carbon monoxide poisoning in the mother and fetus; recognize and diagnose carbon monoxide poisoning in a pregnant patient; explain treatment of carbon monoxide poisoning in pregnancy.