CONGENITAL methemoglobinemia1-4 is a rare, genetically determined abnormality which is of clinical importance mainly because of the marked cyanotic appearance of the carriers of this defect, thus giving rise to the suspicion of the presence of a serious disease. The cyanosis, however, is only rarely associated with other clinical manifestations. This discrepancy is the most important clinical clue to the diagnosis. If, however, this abnormality coexists with another unrelated clinical condition in the course of which cyanosis may occur, it may be mistaken for a sign of a grave complication. An example of such a clinical situation is described in the following report which shows that a person with congenital methemoglobinemia tolerates pregnancy well.
Report of a Case
A 27-year-old woman, Gravida 4, Para 3, born in Puerto Rico, was first seen at the University of Illinois prenatal clinic during the eighth month of pregnancy, complaining of slight shortness
Pepper G, Weinstein HG, Heller P. Congenital Methemoglobinemia in Pregnancy. JAMA. 1961;177(5):328-330. doi:10.1001/jama.1961.73040310021012