In conclusion, we established a model of gestational mice with AV infected by E. coli and found that vaginal infection induced by E. coli during pregnancy in mice could lead to: (i) weight reduction of the mother and fetus and adverse pregnancy outcomes; (ii) reduction in expression of the chemokines, such as CCL-17, CCL-22, and CCL-24 by transformation of M1 macrophages to M2 macrophages; and (iii) a significant decrease in expression of the IL-4/JAK-1/STAT-6 signaling pathway and the downstream gene of GATA-3. Here, STAT6 is linked to infective vaginitis.