Active MRIs Pre-Pregnancy Predict Postpartum Relapse in MS

Disease Spotlight | <b>Disease Spotlight: Multiple Sclerosis</b>

Researchers also found that EDSS score pre-pregnancy was associated with the likelihood of post-partum relapse for patients with multiple sclerosis.

Data from a recent study suggest that brain magnetic resonance imaging activity (MRI) during the year before pregnancy can predict post-partum clinical relapses of multiple sclerosis (MS).

Researchers found that relapses in the first 3 months post-partum were significantly correlated with an active-MRI pre-pregnancy (odds ratio [OR], 6.091 [95% CI, 2.3-16.13]; P <.001) and expanded disability status scale (EDSS) score pre-pregnancy (OR, 1.780 [95% CI, 1.158-.735]; P = .009). 

Senior author Adi Vankin-Dembinsky, MD, PhD, senior neurologist, Hadassah Medical Center, and colleagues wrote that “pregnancy counseling for women with MS still forms an important aspect of disease management due to the increased risk of relapses post-partum and the additional complexity of expanding treatment options for MS.”

Vankin-Dembinsky and colleagues conducted an observational retrospective case-control study of 118 women with MS with a total of 172 pregnancies. The women were an average age of 31.8 years at time of delivery (standard deviation [SD], 4.78), had an average disease duration of 5.7 years (SD, 4.33) at the time of conception, and had an average EDSS score of 1.3 (SD, 1.25) before pregnancy. MRIs were taken a mean of 4.3 months (SD, 4.86) before pregnancy. The women breastfed for a mean of 7.3 months (SD, 5.2) and had a mean EDSS score of 1.4 (SD, 1.35) 1-year post-partum.

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The researchers found that mean annualized relapse rate (ARR) in the year pre-pregnancy was 0.34 (SD, 0.16), with 47 women (27.3%) experiencing a relapse. Overall, 90.11% of pregnancies were relapse-free and mean ARR dropped to 0.069 (SD, 0.04) during the second semester, with 3 women (1.7%) experiencing relapse.

Mean ARR was 1.11 (SD, 0.13) during the first 3 months post-partum, with 44 pregnancies (25.6%) experiencing 48 relapses, 0.53 (SD, 0.1) in the 3- to 6-month period post-partum with 23 patients (13.4%) experiencing 23 relapses, and 0.4 (SD, 0.09) in the 6- to 9-month period post-partum with 15 patients (8.7%) experiencing 17 relapses. Around half of all pregnancies (52.3%; 90 patients) remained relapse-free by the end of the first year post-partum (mean ARR, 0.18 [SD, 0.06]).

Vankin-Dembinsky and colleagues found that 48 women (36.6%) had an active MRI pre-pregnancy. This increased to 64 patients (48.9%) post-partum. They found a significant correlation between having an active MRI pre- and post-pregnancy (P = .011), with an OR of 8.331 (95% CI, 3.608-19.237) of having an active MRI post-partum. 

Relapse during pregnancy correlated with post-partum relapse, with an OR of 3.792; (95% CI, 1.211-11.82; P = .002) of post-partum relapse. Higher EDSS score correlated with a higher relapse rate during 0- to 3-months post-partum (P = .03). Relapses 1 or 2 years before pregnancy were not a significant predictor of relapse in the first 3 months post-partum. Breastfeeding, age at conception, disease duration, oligoclonal bands state, and the number of previous pregnancies were not correlated with post-partum relapses.

Women with active MRIs in the year before pregnancy had an OR of 9.375 (95% CI, 3.825-23.19; P <.0001) of having a relapse post-partum. In multivariate analysis, active-MRI pre-pregnancy (OR, 6.091 [95% CI, 2.3-16.13]; P <.001) and expanded disability status scale (EDSS) score pre-pregnancy (OR, 1.780 [95% CI, 1.158-.735]; P = .009) were significantly correlated with relapses in the first 3 months post-partum. Incorporating data from MRI and EDSS, researchers attempted to predict which women would not experience post-partum relapses. This yielded a 96.7% specificity (P <.001) but only a 30% sensitivity.

Vankin-Dembinsky and colleagues also looked at associations between relapse, pregnancy, and disease modifying therapy (DMT). The correlation between active MRI and early post-partum relapse remained significant in women receiving and not receiving DMTs. They also found that brain MRI activity postpartum (OR, 5.143 [95% CI, 2.348-10.83]; 72% sensitivity) is more sensitive than clinical follow-up for revealing disease activity (OR, 2.912 [95% CI, 1.398-5.901]; 38.7% sensitivity), with 28 post-partum patients (48.3%) with an active-MRI post-partum experiencing no clinical relapses in the year post-partum. 

“This study revealed that an active-MRI is a strong predictor of early post-partum relapses, regardless of whether the woman had clinical evidence of disease activity prior to conception and delivery. Regarding pregnancy counseling in women with MS, our findings emphasize the need to optimize disease control and achieve both clinical and imaging stability before conception to minimize the risk of relapse in the post-partum period,” Vaknin-Dembinsky and colleagues concluded.

REFERENCE
Lehmann H, Zveik O, Levin N, Brill L, Imbar T, Vaknin Dembinksy A. Brain MRI activity during the year before pregnancy can predict post-partum clinical relapses. Mult Scler J. Published online March 30, 2021. doi: 10.1177/13524585211002719