Pain Treatment During Labor Does Not Increase Risk of MS Relapses After Delivery, Study Finds

A certain type of pain-relief treatment during childbirth does not increase the risk that women with multiple sclerosis will have relapses after delivering, a European study reports.

The research involved treatments called neuraxial analgesia, so the scientists titled their study “Neuraxial analgesia is not associated with an increased risk of post-partum relapses in MS.” It appeared in the Multiple Sclerosis Journal.

MS affects more women than men and is typically diagnosed during childbearing years. At one point, researchers were concerned that pregnancy would worsen MS. But recent research has shown that the rate of relapses actually decreases during pregnancy, especially in the final three months.

Studies have also shown that relapses can increase in the first three months after delivery, however. This is particularly true in women who had relapses in the year before their pregnancy, or while pregnant.

A current topic of debate among doctors is whether local anesthetics that decrease a woman’s pain during labor or delivering are toxic. Some doctors are concerned they will trigger MS systems or relapses by acting on nerve fibers that have lost the myelin coating that protects nerve cells.

Many anesthesiologists do not want to administer neuraxial analgesia treatments in particular to women who have had recent relapses. They can be administered either under the skin or to the spine.

To try to shed light on this debate, European researchers decided to look at whether neuraxial analgesia increased the risk of women with MS having relapses in the first three months after delivery.

Their analysis covered two large studies. The PRIMS trial between July 1993 and July 1995 included 215 women from 12 European countries. The POPART’MUS trial between June 2005 and October 2011 involved 174 French and Italian women with relapsing-remitting or secondary progressive MS.

The researchers who conducted the studies recruited women with mild MS disability and no exposure to disease-modifying treatments during pregnancy or in the three months after delivery.

The European researchers analyzing the studies discovered that 156 out of the 389 women, or 40%, were given a neuraxial analgesia. Twenty-four percent had relapses during pregnancy and 25% in the three months after delivery.

Matching earlier findings, women who had a relapse during pregnancy were more likely to have a post-delivery relapse, regardless of whether they received a neuraxial analgesia.

The team did not find a correlation between neuraxial analgesia and post-delivery relapse. This finding was in line with results of the PRIMS and POPART’MUS studies.

Among the research’s limitations, the authors said, were lack of data on the kind of neuraxial analgesia — under the skin or spinal, the anesthetic used, and its concentration. Future studies could benefit from detailed information on the women’s disease manifestations and brain imaging of their condition, the researchers noted.

“Our study provides additional arguments toward the harmlessness of neuraxial analgesia in parturient women [those in labor] with MS, whatever their MS activity during pregnancy,” the team wrote.

“It is important to inform MS women that the post-partum [post-delivery] period is associated with a greater risk of relapse, which is closely related to the pregnancy disease activity but not to the use of local/regional analgesia at the time of delivery,” they wrote.