More Women With Multiple Sclerosis Continuing DMT Use During Pregnancy

Currently, disease-modifying drugs (DMDs) are being used more often among women with multiple sclerosis (MS) of childbearing age, even during pregnancy. This is associated with reduced annualized relapse rates (ARRs) prior to and following delivery in the absence of obstetric complications among this population. These are the findings of a retrospective, observational study published in the journal Multiple Sclerosis and Related Disorders.

MS is a disorder that typically affects young adults in their mid-20s to late 30s, with a women to men ratio of 3:1. Thus, “MS specialists need to consider fertility and pregnancy issues since the very early stage of the disease, when therapeutic choices are made,” according to researchers of the current study. It is well known that the therapeutic management of MS before, during, and after pregnancy can represent a challenge for MS specialists.

Recognizing that up until the 1990s, women with MS were discouraged from becoming pregnant because of a dearth of studies evaluating the impact of pregnancy on the disease course, For the study, researchers sought to describe how pregnancy planning and management among women with MS have evolved over the past 15 years.  They retrospectively collected clinical data from women with relapsing-remitting MS who had been referred to the Neurology Clinic of the University Hospital “Policlinico G. Rodolico” of Catania, Italy, and who became pregnant between 2005 and 2020. They compared data regarding MS and pregnancy between 2 time periods — that is, 2005 to 2012 and 2013 to 2020 — according to onset of pregnancy.

In the study, 190 women with MS were enrolled from a total of 1475 women of childbearing age (ie, 15-45 years) who had been referred to the Italian MS center between 2005 and 2020. Among these women, 53.7% (102 of 190) of them experienced a pregnancy between 2005 and 2012, whereas 46.3% (88 of 190) of them experienced a pregnancy between 2013 and 2020. In 72.6% (138 of 190) of the women, 1 pregnancy was reported, whereas 21.6% (41of 190) of the women and 5.8% (11 of 190) of the women experienced 2 pregnancies and 3 pregnancies, respectively.

When the 2 time periods were compared, the age at MS onset was older in the second group —2013-2020 — than in the first group — 2005-2012 (25.3±5.9 years vs 23.6±5.9 years, respectively; P =.05), as was the age at first pregnancy (33.1±5.7 years vs 30.9±4.6 years, respectively; P <.01). Of 253 pregnancies, 88.1% (223 of 253) of them were reported among women being treated with DMDs — most of them in the second epoch of pregnancy (P =.03).

Women who experienced a pregnancy in the second time period were significantly older (P <.01), were treated significantly more often with high-efficacy DMDs (P <.001), and exhibited significantly lower ARRs both prior to pregnancy (P =.01) and after pregnancy (P <.001), compared with women who experienced a pregnancy in the first time period.

Pregnancies were reported mainly among women treated with interferon-beta (54.2% of all pregnancies), followed by natalizumab (16.6%), glatiramer acetate (8.3%), dimethyl fumarate (3.2%), and other DMDs (in less than 3% of women each). In the first observation period, high-efficacy DMDs were rarely used (3.3% of women), whereas DMDs were the most common therapeutic selection in the second time period (38.4% of women).

“Probably due to increasing knowledge and availability of DMD approved for use during pregnancy and breastfeeding, we detected a higher tendency to not discontinue treatment before conception and to maintain DMD even during pregnancy from 2014 to present,” the researchers noted.

The findings of this study highlighted a trend reversal in DMD use during pregnancy in the last 15 years. The researchers noted that among women with MS who were pregnant, there was a tendency to not discontinue DMD use unless it’s clearly contraindicated, especially in cases where high-efficacy DMD administration took place before conception.

Disclosure: Some of the study authors have declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.