Modern disease-modifying treatments (DMTs) have significantly transformed the management of relapsing-remitting multiple sclerosis (MS). However, their use during pregnancy has been a subject of ongoing concern. A recent study published in The Lancet Regional Health – Europe sheds new light on the safety of these medications for pregnant women, based on data gathered from the German MS and Pregnancy Registry.
The study confirms that several DMTs, including beta-interferons and glatiramer acetate, are safe for use during early pregnancy. Additionally, it suggests that fumarate is likely a safe treatment during pregnancy. For women with highly active MS, natalizumab and CD20 antibodies are also considered viable options.
Dr. Wolfgang Paulus, from the University Women’s Clinic in Ulm, Germany, and the Reproductive Toxicology Advisory Center, explained in an interview with Medscape Medical News that MS patients, especially women of childbearing age, often face the dilemma of needing effective therapy while planning for pregnancy. The uncertainty about whether to continue medication during pregnancy is common among these patients, making the findings of this study particularly valuable.
Limited Safety Data
While numerous DMTs have been approved over the past decades, safety data for their use during pregnancy remains limited. The European Medicines Agency (EMA) mandates that outcome data from at least 1,000 pregnancies with first-trimester exposure to a given therapy be available before confirming its safety. Currently, only beta-interferons and glatiramer acetate have met this threshold.
According to the EMA, natalizumab has not been shown to increase the risk of teratogenic effects during the first trimester, a key finding corroborated by the study led by Nadine Bast from the Neurological Clinic at St. Josef Hospital, Ruhr University Bochum.
Historically, many MS patients discontinued immunomodulatory medications upon learning of their pregnancy. This often led to a wait-and-see approach, where women only restarted treatment if an MS flare-up occurred, often treated with methylprednisolone or prednisolone in shock therapy for 3-5 days. This approach worked because autoimmune diseases like MS tend to become less active during pregnancy. However, Paulus noted that this strategy is no longer the preferred method. Women with MS, especially those with highly active forms of the disease, need effective treatments during pregnancy to prevent relapses.
Treatment Continuation During Pregnancy
Paulus emphasized that women who are stable on medications like beta-interferons, glatiramer acetate, or natalizumab should continue their treatment during pregnancy. Stopping medication increases the risk of disease flare-ups, which can lead to severe complications.
Pregnancy Outcomes and Risks
The study analyzed data from 2,885 pregnancies exposed to DMTs and 837 unexposed pregnancies between 2006 and 2023. The findings revealed that women who continued their DMTs during pregnancy did not experience higher rates of spontaneous abortion, preterm births, or severe congenital malformations compared to those who did not use DMTs. However, women on teriflunomide did experience a higher rate of preterm births (21.9%) compared to the untreated group (9.3%).
Notably, babies born to mothers treated with S1P modulators or CD20 antibodies were more likely to be small for gestational age (SGA), with lower birth weights (132 g less) and shorter lengths (0.91 cm shorter). Similarly, babies whose mothers received natalizumab during the third trimester also had a lower birth weight (74 g less). While the study could not definitively link these growth restrictions to the DMTs, Paulus suggested that the disease itself might have contributed to these outcomes, pointing to the higher SGA rate observed in the general population.
Congenital Malformations and Infections
The study also found no significant differences in congenital malformations between treated and untreated pregnancies, though the incidence was higher in groups treated with teriflunomide (12%) and alemtuzumab (10.5%). The authors noted that the number of cases was too small to make definitive conclusions, especially given that teriflunomide and alemtuzumab have shown potential teratogenic effects in animal studies.
In terms of infections, serious infections were rare (1.6%) but more frequent in the fumarate (2.8%) and alemtuzumab (9.1%) groups compared to the untreated group. The use of systemic antibiotics was also higher among women on natalizumab or CD20 antibodies during the second and third trimesters.
While further research is needed to evaluate the long-term impacts of these treatments, the study emphasizes the importance of continuing therapy for women with highly active MS during pregnancy, especially given the risks of relapse.
Conclusion
This research provides crucial insights into the safety of DMTs during pregnancy and underscores the need for personalized care in women with MS who are planning a pregnancy. As treatment options evolve, ensuring both maternal and fetal safety will remain a priority for clinicians and patients alike. Further studies will be needed to refine guidelines and assess the long-term outcomes for both mothers and children.
Related topics:
EQT AB Considers $400 Million IPO for Indira IVF
Alabama Supreme Court Decision Shakes IVF Community, Families Share Their Struggles
Pregnant Woman’s News Stirs Tension with Infertile Best Friend: Is She in the Wrong?
