OBJECTIVE: Primary bone and soft-tissue tumors occur rarely in pregnancy. T he objective of this study was to describe the outcome of a large cohort of pregna nt patients with these rare tumors. METHODS: Pregnant women diagnosed with bone or soft-tissue tumors during pregnancy or within 3 months after delivery were i dentified retrospectively for the years 1983-2003 in the University Health Netw ork database, University of Toronto. Relevant maternal and neonatal data were co llected on a standardized data form. RESULTS: In more than 60,000 deliveries dur ing the study period, 17 patients were identified. Gestational age at diagnosis ranged from 11 weeks to 2 months postpartum. Eight cases involved the lower extr emity and 6 involved the upper extremity. Osteosarcoma, chondrosarcoma, and gian t-cell tumors were the most common histological types. Metastases occurred in 7 cases. Nine cases were treated surgically during the course of pregnancy. The m ajority of patients were delivered at term. Chemotherapy was deferred until the postpartum period. One patient elected for early termination of pregnancy. Three patients were delivered before 37 weeks of gestation to proceed with therapy. O ne neonate delivered at 34 weeks developed respiratory distress syndrome and req uired intubation. Three patients died, all as the result of metastatic disease. There were no perinatal or infant deaths. CONCLUSION: Most cases of soft-tissue and bone tumors during pregnancy can be successfully managed with surgery durin g gestation. Therapies with fetal toxicity were more likely to be deferred to th e postpartum period. OBJECTIVE: Primary bone and soft-tissue tumors occur rarely in pregnancy. T he objective of this study was to describe the outcome of a large cohort of pregna nt patients with these rare tumors. METHODS: Pregnant women diagnosed with bone or soft-tissue tumors during pregnancy or within 3 months after delivery were i dentified retrospectively for the years 1983-2003 in the University Health Netw ork database, University of Toronto. Relevant maternal and neonatal data were co llected on a standardized data form. RESULTS: In more than 60,000 deliveries dur ing the study period, 17 patients were identified. Gestational age at diagnosis ranged from 11 weeks to 2 months postpartum. Eight cases involved the lower extr emity and 6 involved the upper extremity. Osteosarcoma, chondrosarcoma, and gian t-cell tumors were the most common histological types. Metastases occurred in 7 cases. Nine cases were treated surgically during the course of pregnancy. The mjorjor of patients were delivered at term. Chemotherapy was deferred until the postpartum period. One patient elected for early termination of pregnancy. Three patients were delivered before 37 weeks of gestation to proceed with therapy. Three neurated delivered at 34 weeks developed respiratory distress syndrome and req uired intubation. Three There were no perinatal or infant deaths. CONCLUSION: Most cases of soft-tissue and bone tumors during pregnancy can be successfully managed with surgery durin g gestation. Therapies with fetal toxicity were more likely to be deferred to th e postpartum period.