Several therapeutic regimens have been proposed for women with recurrent spontaneous abortion (RSA) and antiphospholipid antibodies (APA). Conflicting results have been reported about women with history of RSA, positive APA, and failure of standard therapy. To evaluate the use of intravenous immunoglobulin in RSA patients with APA and history of treatment failure, we initiated a study with standard therapy (aspirin and low-molecular-weight heparin) and intravenous immunoglobulin. We used an enzyme-linked immunosorbent assay (ELISA) test to screen IgG and IgM anticardiolipin antibodies, and a diluted Russel viper venom time assay for the lupus anticoagulant activity. Altogether, 66 pregnant women with positive APAs at the first visit could be included. Patients with hereditable thrombophilic factors were excluded. After confirmation of the pregnancy, women received a basis immunization of 0.3 g/kg immunoglobulin in a 4-week cycle until the 28th to 32nd week of gestation. All patients received 100 mg/d aspirin and 3,000 anti-Xa U/d certoparin. Among the 66 pregnant women, 17 were persistently autoantibody positive (25.8%), of whom 11 (16.7%) were ACA positive alone, 2 (3%) were lupus anticoagulant positive, and 4 (6.4%) had both antibody types. A total of 49 patients had positive APAs at the initial test, but were negative for ACA and lupus anticoagulant at the second test administered approximately 5 weeks after the start of therapy. We described this group in our following observation as "antibody negative." Sixteen of the 17 autoantibody-positive patients (94.1%) were delivered of live infants compared with 40 patients (81.6%) in the antibody-negative group (odds ratio [OR]: 1.2; 95% CI: 0.98 to 1.4). The overall miscarriage rate was 12.1% and the fetal loss rate was 15.2%. Four patients (25%) in the antibody-positive group developed symptoms of preeclampsia and fetal growth retardation compared with four patients (9.8%) in the antibody-negative group. In conclusion, we see a reduction of the fetal loss rate in patients with RSA and positive APA (5.8%) compared with APA-negative (18.4%) women with the same therapy (OR: 0.3; 95% CI: 0.04 to 2.3).