The pooled estimates showed no increased risk of spontaneous abortion (OR 1.09; 95% CI: 0.73–1.63; P = 0.672), stillbirth (OR 1.38, 95% CI: 0.51–3.72; P = 0.530), preterm delivery (OR 1.24, 95% CI: 0.85–1.81; P = 0.260), and maternal complications (OR 0.72, 95% CI: 0.38–1.38; P = 0.326) among patients exposed to IFN compared with the patients unexposed to IFN prior to conception or during pregnancy (Figure 3A). This evidence concerns the gene IFNA1 and abortion.