Objective: To analyze the maternal and fetal outcomes of pregnancies complicated by aplastic anemia (AA) and to investigate the underlying risk factors. Methods: In this retrospective case control study, we retrieved medical records of 85 singleton gravidas with AA (AA group) who were admitted to Peking University People's Hospital from January 2003 to January 2016, and another 340 singleton gravidas (case∶control=1∶4) without blood system or immune system diseases who gave birth at the same period were selected as the control group. Differences in general condition and the incidence of maternal and neonatal complications were compared between the two groups. AA group were further divided into adverse outcome subgroup (n=33) and non-adverse outcome subgroup (n=52), and relevant factors were also analyzed. Statistical analysis was performed using t-test, Chi-square test and logistic regression. Results: No maternal deaths occurred in all 85 cases of AA group, 81 of them gave live birth [one neonate died and the others survived with a mean gestational age of 36⁺⁵ weeks (30⁺²-40⁺⁵ weeks)], and 45 developed maternal or fetal adverse outcomes. Compared with the control group, AA group had higher incidences of hypertensive disorders of pregnancy [20.0% (17/85) vs 6.2% (21/340)], acute heart failure [7.1% (6/85) vs 0.0% (0/340)], postpartum hemorrhage [5.9% (5/85) vs 0.9% (3/340)], puerperal infection [2.4% (2/85) vs 0.0% (0/340)], preterm birth [22.3% (19/85) vs 5.6% (19/340)], small for gestational age [11.7% (10/85) vs 0.9% (3/340)], fetal growth restriction [8.2% (7/85) vs 1.2% (4/340)], intrauterine fetal death [4.7% (4/85) vs 0.0% (0/340)] and neonatal death [1.2% (1/85) vs 0.0% (0/340)] (all P<0.05). After adjusting for age, pregnancy history and the time of diagnosis, we found that low median (OR=0.88, 95%CI: 0.83-0.95), mean (OR=0.85, 95%CI: 0.79-0.93) and minimal (OR=0.87, 95%CI: 0.82-0.93) values of hemoglobin concentration during pregnancy, and low median (OR=0.96, 95%CI: 0.92-1.00), mean (OR=0.96, 95%CI: 0.92-1.00) and minimal (OR=0.95, 95%CI: 0.90-0.99) values of platelet counts during pregnancy were risk factors for adverse maternal and fetal outcomes of gravidas with AA (all P<0.05). Conclusions Maternal and fetal complications are more common in pregnant women with AA and maintain hemoglobin and platelet counts at a certain level may improve the outcomes.