Photo Credit: Natalia Kuzina

While pregnancy is safe for women with multiple sclerosis, fertility treatments can impact relapse risk, and all patients require ongoing specialist support.

Pregnancy is safe for women with multiple sclerosis (MS) and their babies, according to results of a prospective, longitudinal pregnancy registry of non-disabled women with MS in the Northeastern US.

“People with MS tend to do well in pregnancy but are at higher risk for relapses after pregnancy,” lead study author Maria K. Houtchens, MD, tells Physician’s Weekly (PW). “This tendency has been mitigated to some degree by effective, well-tolerated, modern medications, some of which continue to provide beneficial effects throughout pregnancy. Interestingly, many participants who had postpartum relapses also had some type of fertility support for their pregnancy, supporting hormonal-immune interactions as disease modulators in MS.”

The PREG-MS Registry

To develop the prospective MS pregnancy registry (PREG-MS), Dr. Houtchens and colleagues recruited participants at 11 academic and community MS treatment centers from 2017 to 2020. The researchers followed them and their children from conception attempts and any pregnancy trimester through 3 years postpartum.

Among 146 enrolled participants, there were 122 pregnancies from 135 participants and 105 babies born. Overall, 24.6% of pregnancies were unplanned and 14.1% had an infertility diagnosis. A small number of pregnancies (12.6%) used assistive reproductive technologies. More than half (54%) of pregnancies were considered high-risk, and approximately 40% had peripartum obstetric complications with 17% adverse pregnancy outcomes.

The researchers found that:

• 33.6% of participants were exposed to disease-modifying therapy in pregnancy.
• 19.7% of participants had one or more relapses within 1 year before pregnancy, and the risk for relapses highly correlated with increased duration of conception attempts (P<0.0001).
• Any fertility treatments predicted intrapartum relapses independent of disease-modifying therapy status (OR 5.18; 95% CI, 1.58-17.02; P=0.007).
• 12% had intrapartum relapses and 24.5% had postpartum relapses, with intrapartum relapses (P=0.008) and high-risk pregnancy (P=0.036) linked with postpartum exacerbations.

Lead study author Maria K. Houtchens, MD, talked with Physician’s Weekly (PW) about the study and its potential impacts on the care of women with MS who are considering pregnancy or are pregnant.

PW: Why was it important to do this study?

Maria K. Houtchens, MD: Prospective disease registries are standard in Europe. By contrast, a prospective MS pregnancy registry has never been done in the US. Pregnancy registries in this country instead fulfill the FDA’s requirement that pharmaceutical manufacturers conduct safety studies for the approval of all drugs, including those for MS.

This is the first, proof-of-concept study that looked at the condition itself, regardless of whether participants were treated and what they were treated with. Such studies can be conducted in private practices and academic centers in diverse communities anywhere in the US, and we can ask and answer specific questions about whatever outcomes we want to investigate.

Did the findings surprise you?

Our study yielded interesting, high-quality data. Some results surprised us, and others were expected, as they confirmed the results of other studies. All were interesting and good to have.

We found that the trend was quite similar to what had previously been described despite the fact that we are now 20+ years after the original study that described that finding. It was interesting that many participants who had postpartum relapses also had fertility support for their pregnancy.

We were surprised that the diagnosis of MS was an impetus to designate a pregnant patient as having a high-risk pregnancy. That makes sense on a psychological level. An obstetrician managing a pregnant patient with a concerning chronic condition will mark them as potentially requiring more care throughout their pregnancy. But we did not expect to find as many patients [who] considered high-risk pregnancy as [much as] we did.

Our study showed that patients with MS do well with pregnancy outcomes and likely don’t need to be designated high-risk pregnancy unless they are at high risk from the obstetric perspective or having other, non-neurologic complications.

 How could the registry affect the care of pregnant patients with MS?

We want to make sure this information is widely disseminated so it can help the greatest number of community neurologists possible.

Twenty or thirty years ago, physicians advised their MS patients who were pregnant or considering pregnancy to be very careful due to concerns about outcomes for them, their disease, and their children.

With this study and others, we are trying to change the paradigm, especially among community neurologists, because they take care of most patients with MS in the community. We want to ensure that those providers feel comfortable giving their patients appropriate and accurate family planning and reproductive health recommendations.

If you have MS and are pregnant, it’s safe for you to be pregnant while you have recently been on certain medications such as some B-cell depleting therapies, for example, but other treatments may not be compatible with pregnancy. The bottom line is that our patients no longer have to choose between a safe pregnancy and motherhood versus effectively treating their MS. They can have both!

What questions remain unanswered for you?

In our study, patients with pregnancies resulting from fertility treatments or assisted reproduction techniques of any kind seemed to have a bit more disease activity postpartum than those who were not on fertility treatments. Many conflicting studies have been published on this subject, and we would like to investigate this in more detail.

We couldn’t and didn’t address any unusual pathways to pregnancy that people might take, so it’s not clear how that may affect the outcomes with MS or any other conditions. We have no data to guide sexual minorities with MS through pregnancy, and it would be interesting additional work to do.

We have comparatively little data on how pregnancy affects patients with other demyelinating diseases. I would like to explore those outcomes in larger prospective studies, to address those questions and better understand the outcomes in those populations, and we are actively working on this now.

 Do you have any additional comments to share with clinicians?

We now have 23 disease-modifying treatments for MS. It’s very difficult for general neurologists who treat a multitude of conditions to stay up to date and be comfortable with MS and its specialized treatments, such as pregnancy. So, while it’s important for community neurologists to feel at ease asking their patients about pregnancy, they should refer their patients for specific consultations regarding reproductive issues and family planning.

We know that clinicians in private practice don’t want to lose their patients to specialists. When their patients come to us for family planning consultations, we manage them through their pregnancy, then send them back to their community providers. We are among a handful of specialists in the US who can help with this, and we are available to do so!