Objective:

Background:

MS disproportionately affects women of childbearing age. Prior studies have demonstrated that relapse rates in women with MS decreases during pregnancy but increases substantially in the first several months postpartum. The effect of highly effective DMT on postpartum relapse rates, including radiographic changes, has not been well established

Design/Methods:

A retrospective chart review of women who had successfully completed one pregnancy at the University of Colorado from 2013-2023 was done. Inclusion criteria included the use of a DMT prepartum and follow up for at least one year after delivery. Those with incomplete data were not included.

Results:

A total of 194 patients and 252 pregnancies were identified. The cohort was primarily Caucasian (n=192, 76%) and non-Hispanic (n=219, 87%). The average age at conception was 31.8 years (SD 4.9) with average duration of MS diagnosis at conception of 6.2 years (SD 4.4). The majority were on an anti-CD20 therapy prepartum (n=122, 48%), followed by glatiramer acetate (n=58, 23%) and natalizumab (n=35, 14%). There was a statistically significant difference in postpartum vs preconception relapse rate ratio noted only in the anti-cd20 group (rate ratio 0.37, p=-0.028). 219 pregnancies had postpartum MRI scans that had a prepartum MRI comparison. In those on anti-CD20 therapies, 8/109 (7%) had new postpartum lesions compared to 15/30 (50%) postpartum MRI scans in natalizumab treated patients with an anti-CD20 vs natalizumab risk ratio estimate of 0.15 (p=0.0002[EA1] ).  

Conclusions:

Our data demonstrate a lower postpartum relapse and new MRI lesion rate compared to prepartum rates on anti-CD20 therapies, a stark contrast to existing published data. This may indicate a new treatment paradigm for people living with MS of childbearing age that desire pregnancy.