What the Study Looked At
The study analyzed 2,885 pregnancies from the German Multiple Sclerosis and Pregnancy Registry, spanning data collected between 2006 and 2023. It examined women exposed to a variety of DMTs, including:
Interferons
Glatiramer acetate
Dimethyl fumarate
Teriflunomide
S1P modulators (like fingolimod and ponesimod)
Alemtuzumab
Natalizumab
Anti-CD20 antibodies (rituximab, ocrelizumab, ofatumumab)
Cladribine
For comparison, the study also included 837 women with MS who didn’t take any MS medication during pregnancy.
Key Findings
No Major Increase in Pregnancy Risks
Most DMTs did not significantly increase the risk of complications like spontaneous abortions, premature births, or major birth defects.
However, the data for medications like cladribine, teriflunomide, and alemtuzumab was limited, making it harder to draw firm conclusions about rare complications, such as severe infections or birth defects.
Low Birth Weight Was a Concern
Babies born to mothers with MS—whether or not they took DMTs—were more likely to have a lower-than-average birth weight.
18.8% of babies in the study had low birth weight compared to 10% nationally in Germany.
The risk was highest with S1P modulators (27.4%) and anti-CD20 antibodies (24.1%).
Low birth weight is a concern because it can lead to complications, including neonatal death and long-term health risks like type 2 diabetes and cardiovascular disease.
Infections Were Rare but Monitored
Serious infections were infrequent, but:
Fumarate (2.8%) and alemtuzumab (9.1%) were linked to more infections during pregnancy.
Severe infections were slightly higher in cases treated with natalizumab in late pregnancy (3%) or S1P modulators (3%).
Anti-CD20 therapies, surprisingly, were associated with a lower rate of severe infections (0.6%) than expected.
Women exposed to natalizumab or anti-CD20 antibodies were more likely to need antibiotics during pregnancy.
What Does This Mean for Pregnant Women with MS?
While the findings are reassuring overall, they underscore the importance of an individual risk-benefit assessment when deciding whether to continue MS medications during pregnancy.
Monitoring is Key: Pregnant women with MS should work closely with their healthcare providers to ensure their treatment plan balances managing their MS symptoms with minimizing potential risks to the baby.
More Research Needed: The registry will continue tracking outcomes to see if babies with low birth weight eventually catch up in growth.
Conclusion
The study offers valuable insights into how MS medications interact with pregnancy. While most DMTs don’t pose a significant risk, some may influence birth weight or infection risk, emphasizing the need for personalized care and close medical supervision.
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