Babesiosis in pregnancy.

Babesiosis is a malaria-like illness due to intraerythrocytic protozoan parasites. To the authors' knowledge, this unusual disease has not previously been described in a pregnant woman. Herein is reported the case of a gravid woman with an intact spleen who developed infection with Babesia microti in the fifth month of gestation. Her illness resolved following supportive care only, and evidence of transmission of disease to the fetus was not found.