Antinuclear antibodies and recurrent miscarriage: Systematic review and meta-analysis.

Studies have investigated the relationship between antinuclear antibodies (ANA) and recurrent miscarriage (RM). The objective of this paper is to evaluate the presence of ANA as a risk factor for spontaneous abortion in patients with RM. By considering the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analysis, the authors performed systematic review and meta-analysis by searching the databases of PubMed/Medline and SCOPUS. Review Manager, Version 5.3 performed the statistical analysis. Binary variables were analyzed by odds ratio (ORs) and 95% confidence interval (CI). The subgroup analysis compared the effect of different ANA titers. The authors analyzed the ANA patterns of immunofluorescence staining. Seven case-control studies were selected. The frequency of positive ANA was statistically higher in the RM group (20.6%, 288/1400) as compared to the control group (6.7%, 72/1080). The meta-analysis of the positive ANA showed a statistical difference between the two groups (OR 3.30, 95% CI 1.41-7.73; I2  = 87%, P = .006). Studies have revealed different frequencies of ANA patterns of immunofluorescence. This meta-analysis suggested that positive ANA might increase the risk of RM. However, it was not possible to conclude which ANA pattern of immunofluorescence staining is more frequent in the RM group.