RESUMEN
BACKGROUND: Systemic lupus erythematosus (SLE) often requires administration of cyclophosphamide (CYC), especially for severe glomerulonephritis. As this disease usually affects young women in reproductive age, pregnancy, though not recommended may occur. The teratogenic effects of this drug make pregnancy prognosis and fetal survival indeterminate. METHODS: We reviewed retrospectively the medical records of five patients with SLE who received inadvertently CYC during pregnancy and analyzed fetal outcome. RESULTS: All patients were exposed at the first trimester. Two patients suffered miscarriages, two went to full term and one presented premature labor. CONCLUSION: In spite of potential successful pregnancies after CYC exposure, this drug has teratogenic effects and prescription must be avoided during the pregnancy period. At the same time, the occurrence of these reported unplanned pregnancies strengthen the need of improving patients' education on pregnancy risks during immunosuppressive treatment.