We examined the relation between the spontaneous remission and prednisolone-induced suppression of lupus anticoagulant (LAC) or anticardiolipin antibody (ACA) and pregnancy outcome in 5 LAC-positive women. Two women showed a spontaneous remission of LAC and ACA during the observation period. One of these 2 women became pregnant and delivered healthy twin infants at 36 weeks of pregnancy without any therapy. The other woman became LAC positive again after 1 year of remission, and experienced 2 more fetal losses. Two of the remaining LAC-positive women received prednisolone and aspirin. Only 1 woman, whose ACA was suppressed by medication, delivered a healthy newborn. The pregnancy of the other woman, whose LAC and ACA remained positive in spite of medication, terminated in an IUFD. These results suggest that the administration of prednisolone and aspirin is the first choice of therapy for LAC-positive women, and that encouraging such women to become pregnant while LAC is negative might be an alternative therapy.