Background: Nitrous oxide can cause disordered blood cell proliferation and lead to pancytopenia and altered immune function.
Case Report: A young pregnant female patient presented after binge nitrous oxide abuse with altered mental status and abnormal vital signs. From her initial assessment she was noted to have pancytopenia and was found to have megaloblastic, hyper-cellular changes in a subsequent bone marrow biopsy. This presentation was determined to be secondary to toxic effects after heavy use of nitrous oxide.
Conclusions: Nitrous oxide exposure, including use as an inhalant, over 12 hours can lead to bone marrow abnormalities such as megaloblastic hematopoiesis.

Keywords: Pregnancy, megaloblastic hematopoiesis, Hematopoiesis, Nitrous Oxide - toxicity