Laboratory results are frequently abnormal in pregnant mothers. Abnormalities usually relate to pregnancy or associated complications. Hematological abnormalities and age in pregnancy may increase the likelihood for transfusion and mortality. Hematological profiles and transfusion history of pregnant mothers presenting to a tertiary hospital, were evaluated over 2 years. Age, anemia, leukocytosis and thrombocytopenia were assessed for transfusion likelihood. Iron deficiency and coagulation were assessed in transfused patients. Anemia, leukocytosis, thrombocytopenia, human immunodeficiency virus (HIV) and transfusion were assessed for mortality likelihood. There were 12,889 pregnant mothers included. Mothers <19-years-old had the highest prevalence of anemia (31.5%) and proportion of transfusions (19%). The transfusion likelihood was increased in mothers with anemia (odds ratios [OR] = 6.41; confidence intervals at 95% [95% CI] 5.46-7.71), leukocytosis (OR = 2.35; 95% CI 2.00-2.76) or thrombocytopenia (OR = 2.71; 95% CI 2.21-3.33). Mothers with prolonged prothrombin times received twice as many blood products as their normal counterparts (p = .03) and those with iron deficiency anemia five times more blood products (p < .001). Increased likelihood for mortality was seen in patients with anemia (OR = 4.15, 95% CI 2.03-8.49), leukocytosis (OR = 2.68; 95% CI 1.19-6.04) and those receiving blood transfusion (OR = 3.6, 95% CI 1.75-7.47). Adolescence, anemia, leukocytosis and thrombocytopenia expose mothers to a high risk for transfusion and/or mortality. These risk factors should promptly trigger management and referral of patients. Presenting hematological profiles are strong predictors of maternal outcome and transfusion risk.