Pregnancy Rates Increasing in Women With Multiple Sclerosis

Megan Brooks

October 11, 2018

Pregnancy rates in women with multiple sclerosis (MS) are increasing, confirming the well-established "down-up trend" for reduced relapse risk during pregnancy and the abrupt increase in relapse risk after delivery, new research shows  

Maria Houtchens, MD, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, and colleagues analyzed and compared pregnancy rates and outcomes in US women with and without MS using administrative claims databases.

Between January 2006 and June 2015, the adjusted proportion of women with MS who became pregnant increased from 7.91% to 9.47%, while the percentage of women without MS who became pregnant decreased from 8.83% to 7.75%. 

This translated to a significant increase in annual pregnancy rates of 0.17% for women with MS and a decrease of 0.15% for women without the disease.

The study was published online September 28 in Neurology.

Better Management

The fact that pregnancy rates have been increasing over the past 10 years in women with MS "may suggest that clinicians are becoming more comfortable managing the complex reciprocal effects of MS and pregnancy and that significant efforts on the part of the MS neurology community to educate the public and general neurologists are allowing more women with MS to experience motherhood," the investigators write.

The study also showed that women with MS became pregnant at a slightly older age, generally 2 to 3 years later, than those without MS. This likely reflects both the complexity of the decision to start or grow a family and perhaps the need to get MS under control or stop ongoing disease-modifying drug (DMD) therapy before conception, the researchers suggest.

In a matched analysis of 2115 women with MS and 2115 without MS who had a live birth, more women with MS had premature labor (31.4% vs 27.4%), infection (13.3% vs 10.9%), cardiovascular disease (3% vs 1.9%), anemia/acquired coagulation disorders (2.5% vs 1.3%), neurologic complications (1.6% vs 0.6%), sexually transmitted diseases (0.4% vs 0.1%), acquired fetal damage (27.8% vs 23.5%), and congenital fetal malformations (13.2% vs 10.3%) compared with women without MS.

"These data, which are derived from reimbursement information or the payment of bills for healthcare services and commodities, can improve our knowledge of the interactions that patients with pregnancy and MS have with the healthcare system, but they should be interpreted with caution," the researchers note.

"For example, there may be increased healthcare resource utilization in women with MS because of increased vigilance of clinicians caring for these patients," they point out. Also, they didn't have data on Expanded Disability Status Scale score, disease duration, or the numbers or outcomes of prior pregnancies.

Undertreated in Pregnancy?

In a companion article, Houtchens and colleagues describe relapse and DMD use in 2158 women with MS and a live birth.

They note that the odds of relapse declined during pregnancy (odds ratio [OR], 0.62; 95% CI, 0.52 - 0.74; P < .0001), increased during puerperium (OR, 1.71; 95% CI, 1.36 - 2.15; P < .0001), and ended at a higher level during the last three postpartum quarters (OR, 1.22; 95% CI, 1.05 - 1.41; P = .0081).

The researchers also found that DMD use before pregnancy was "rather low" (roughly 20%), bottoming out at 1.9% during the second trimester and peaking at 25.5% 9 to 12 months postpartum. 

DMD use significantly declined during pregnancy (OR, 0.17; 95% CI, 0.14 - 0.20; P < .0001), remained lower during puerperium (OR, 0.36; 95% CI, 0.31 - 0.42; P < .0001), and ended at a higher level during the last three postpartum quarters (OR, 1.26; 95% CI, 1.16 - 1.37; P < .0001).

In an accompanying editorial, Paola Cavalla, MD, MS Center City of Health and Science University Hospital, Turin, Italy, and Wendy Gilmore, PhD, USC MS Center in Los Angeles, note these data confirm the well-established "down-up trend" for reduced relapse risk during pregnancy and the abrupt increase in relapse risk postpartum.

They also suggest that the increasing pregnancy rates in this patient population "may be attributable to development of appropriate, proactive, and timely family planning counseling in MS centers worldwide. Thus, many centers have included interdisciplinary approaches to counseling that provide reassurance to patients that pregnancy is feasible and positive outcomes are possible with appropriate management practices."

However, an "issue of concern" is the low rate of DMD use in the year before and after pregnancy, the editorialists write. 

As expected, the rate of DMD use was higher in women with more relapses before and after pregnancy. It's possible that the low rate of DMD use after pregnancy may reflect breastfeeding practices, as lactating women generally avoid DMDs, they point out.

Both studies were funded by EMD Serono, a company of Merck. Houtchens has received funding support from EMD Serono; support for service on scientific advisory boards from Biogen, Genzyme Sanofi, Teva Neuroscience, and Novartis; and research support from Genzyme Sanofi. A complete list of disclosures for the authors and editorialists can be found with the original articles.

Neurology. Published online September 28, 2018. Abstract, Abstract, Editorial

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