This study was designed to investigate the risk of ovarian failure and the pregnancy outcomes in women treated with intravenous cyclophosphamide (IVCYC) pulse therapy for lupus nephritis. Sixty-seven women with proliferative lupus nephritis were studied. The clinical and laboratory data, SLEDAI and damage indices at IVCYC initiation, doses and numbers of IVCYC pulses, pregnancy and fetal outcomes were evaluated. During a follow-up of 74.4+/-20.6 months, amenorrhea occurred in 25 (37.3%) and was sustained permanently in 10 patients (14.9%). Thirteen women became pregnant with a total of 19 pregnancies. Seventeen pregnancies ended without complications and all babies were born healthy without any congenital anomalies or perinatal illnesses. Two pregnancies were terminated by induced abortion but no congenital anomaly was noted in these cases. Logistic regression analysis showed that old age, high damage index at the initiation of IVCYC pulse therapy and high cumulative dosage of IVCYC were the independent risk factors of ovarian failure, and that the presence of amenorrhea, regardless of its duration, was the risk factor of pregnancy failure. Pregnancy was possible with a favorable outcome after the withdrawal of IVCYC pulse therapy, unless amenorrhea develops.