4.5. Data Analysis

The two-sample t-test and the Mann–Whitney U test were used for the clinical profiles. The associations between PAI-1, t-PA, and REN gene polymorphisms and RPL susceptibility were determined by age-adjusted odds ratios (AOR) and 95% confidence intervals (CIs). Allele frequencies were determined to confirm deviations from the Hardy–Weinberg equilibrium. The allele combinations for the polymorphisms were estimated by the chi-square test and were adjusted using the false discovery rate correction. The association between each PAI-1, t-PA, and REN gene polymorphism and each clinical value (homocysteine, folate, PLT, aPTT, NK cell, PT, uric acid, total cholesterol, PAI-1, and VEGF) for the RPL patients were assessed by ANOVA and Kruskal–Wallis tests. We considered the p < 0.05 of all statistic tests as statistically significant. Analyses were performed using GraphPad Prism 4.0 (GraphPad Software Inc., San Diego, CA, USA) and Medcalc version 12.7.1.0 (Medcalc Software, Mariakerke, Belgium).