We describe the cases of 2 infants with congenital babesiosis born to mothers with prepartum Lyme disease and subclinical Babesia microti infection. The infants both developed anemia, neutropenia, and thrombocytopenia, and 1 infant required red blood cell transfusion. Both infants recovered with treatment. Additional studies are warranted to define the optimal management strategy for pregnant women with early Lyme disease in geographic areas in which B microti infection is endemic.

Neutropenia appears to be a common finding in infants with congenital babesiosis and is also observed not infrequently in adults with this infection.