AQP4 and neuromyelitis optica: Figure 2 shows the possible mechanisms of NMOSD pathogenesis during pregnancy. However, Quick and Cipolla (124) showed an up-regulation of the AQP4 in the CNS during pregnancy in mice. Saadoun et al. (125) reported a miscarriage rate of 13% in patients NMOSD and discovered that NMO-IgG triggers placentitis, causing fetal death in mice.