The Acute Treatment of Methemoglobinemia in Pregnancy

Methemoglobinemia is a rare, potentially lethal, but treatable condition. In the setting of pregnancy, methemoglobinemia can pose a significant risk to the mother and fetus by causing acute hypoxia. Because methemoglobinemia can be acquired or congenital, treatments vary based on the etiology. Methylene blue is the mainstay treatment for symptomatic methemoglobinemia of levels > 20%. The teratogenic risks of methylene blue require risk−benefit analysis and discussion with the patient before utilization. Systemic maternal administration is theorized to be of lowest risk to the fetus. In this case, methylene blue was used safely as an emergent therapy for congenital methemoglobinemia during pregnancy.