Pregnancy may influence course of neuromyelitis optica

The authors of this article published in Neurology performed a retrospective study on the influence of pregnancy, epidural analgesia and breastfeeding on the course of neuromyelitis optica (NMO). The results demonstrate that pregnancy influences the activity of NMO and may have a greater effect on disability in patients with NMO than those with multiple sclerosis. However, they found no evidence that either epidural analgesia or breastfeeding has an effect on NMO.

Although NMO can affect women in their childbearing years, the effect of pregnancy on its course has never been assessed. The authors reviewed the files of 20 women (including 25 pregnancies) with NMO seen at six tertiary medical centers in France. They noted the number of relapses during the year before pregnancy, during each of the trimesters of pregnancy and during the four trimesters following pregnancy.

Comparisons between the annualized relapse rate of each period found only an increased tendency for a reduced rate between the year before pregnancy (1.0 ± 0.09) and the second trimester (0.8 ± 0.06, P = 0.07). The Kurtzke Expanded Disability Status score increased from 1.5 ± 1.7 before pregnancy to 2.6 ± 1.9 during the year after pregnancy (P = 0.027).

While NMO is a TH2-mediated autoimmune disease, the authors say the study's results make it seem unlikely that the TH1/TH2 cytokine balance is the main pathophysiologic pathway of NMO activity during pregnancy.

They say the results justify close medical monitoring of women with NMO during pregnancy, and suggest the performance of a larger, prospective study in order to confirm the current findings.