A 36-year-old G2P1 woman at 24 weeks gestation is noted to have fatigue of 4 weeks duration. Her hemoglobin level is 8.0 g/ dL, leukocyte count is 2.0 cells/ uL, and platelet count is 20,000/ uL. Which of the following is the most likely diagnosis

Pancytopenia, a reduction in the number of RBCs, WBCs, and platelets circulating throughout the body, suggests a bone marrow process. None of the other answer choices involve low leukocyte counts (leucopenia). Low platelets (thrombocytopenia) may also be a manifestation of severe preeclampsia, and is pa of the criteria for HELLP syndrome as well. Iron deficiency anemia involves low hemoglobin levels and is common in pregnancy due to decreased iron stored prior to pregnancy, and increased demands for iron during pregnancy. Since this patient's blood work showed low WBCs, a bone marrow biopsy should be done. A pregnant woman with leukemia may require chemotherapy, which poses a risk of intrauterine growth retardation to the developing fetus. Acute leukemia itself carries a risk for preterm labor, spontaneous aboion, and stillbih.