Prevalence and clinical significance of antinuclear antibodies in Iranian women with unexplained recurrent miscarriage

Background: Antinuclear antibodies (ANAs) in women with recurrent miscarriage have been reported. The presence of moderate to high titers of these antibodies represents an autoimmune condition that can endanger the health of the fetus in pregnant women. Objective: In this study, we evaluated the prevalence of ANAs in Iranian women with a history of two or more unexplained abortion. Materials and Methods: 560 women with unexplained recurrent miscarriage and 560 healthy controls accounted for this study over a period of 13 months. ANAs were detected by indirect immunofluorescence technique. Results: ANAs were detected in 74 of 560 (13.21%) patient with recurrent miscarriage, and in only 5 of 560 (0.9%) controls (p<0.001). ANA positivity was generally found with low-positive results (1.40-1.80) in about 38% of positive cases, whereas moderate titres (1.160-1.320) and high titres (>1.640) were seen in about 46% and 16% of cases respectively. Finally evaluating of microscopic ANA patterns revealed that about half of positive cases had antibodies against DNA- histone complex, associated with systemic lupus erythematosus disease. Conclusion: Antinuclear antibodies are not uncommon in women with unexplained recurrent miscarriage, suggesting the possible role of an autoimmune disorder on abortion, at least in a subgroup of patients.