Less than a hundred cases of pregnancies in women with neuromyelitis optica (NMO) have been published in the world. The aim of the present study was to add the Brazilian experience to this subject. Cases of women with NMO who became pregnant, or who developed NMO soon after pregnancy, were included. Retrospective analysis of medical data from these patients was carried out by the neurologist responsible for the case. Seventeen cases of pregnancies (16 full-term pregnancies, one miscarriage) were identified. The relapse rate of demyelinating events in the first trimester after pregnancy was significantly higher than at any other time. Disability progression was significantly worse 1 year after delivery. Pregnancy negatively influenced the disease course of NMO in these women. These results are similar to those of other authors, although the total number of cases so far described is still small. Obstetricians must be aware of the potential complications of a pregnancy in a woman who has NMO.