What are the possible complications of multiple sclerosis on pregnancy?

Updated: Aug 20, 2019
  • Author: Carmel Armon, MD, MSc, MHS; Chief Editor: Stephen A Berman, MD, PhD, MBA  more...
  • Print


Complications of pregnancy are generally thought to affect women with multiple sclerosis (MS) no more often than they affect women in the general population. This belief extends as far back as 1948 [36] and is supported by data from numerous subsequent studies of fertility, pregnancy, and delivery. [37] Data also suggest that the risk of spontaneous abortions, congenital malformations, stillbirths, and complications of pregnancy (eg, preeclampsia, premature delivery) is not increased. [38]

Although many findings weigh against the idea that there is a higher risk of low birth weight in infants of mothers with MS, a retrospective study of the Norwegian national registry showed an increased rate of neonates being small for their gestational age (SGA). [39] These neonates had a reduced mean birth weight and length but normal head circumference. The etiology was unclear, though the subtle morphologic changes in the pelvic organs of women with MS may result in suboptimal intrauterine conditions that influence fetal development.

The data also suggested an effect on deliveries. [39] Although the number of planned cesarean deliveries increased, women delivering vaginally had an increased incidence of slow labor progression necessitating interventions. This result may have been partly due to perineal weakness and spasticity and fatigue related to MS.

These findings were countered by those of a 3-year prospective study that reported normal distributions of weight and head circumferences in babies born to mothers with multiple sclerosis. [40] Rates of infant death, congenital anomalies, and cesarean deliveries were also similar to those of the general population.

The reasons for the discrepancies in these studies are unclear. It is certainly possible that differences in the severity and localization of disease in the patient populations of each study could play a role in the outcomes, particularly if perineal and bladder involvement differed. Factors increasing the frequencies of pelvic infections may also play a role.

Although MS is unlikely to have a serious effect on pregnancy, each patient should be evaluated on an individual basis. Patients with clinically significant bladder and perineal involvement and excessive fatigue should be counseled about possible interventions that may help facilitate delivery.

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!