Hi, it's totally normal to have a lot of questions and be anxious when trying to conceive but for someone with MS who's on a DMD, i think it can totally throw your anxiety levels through the roof....deep breath!
"Most disease modifying therapies used to treat MS are not recommended for use during pregnancy or in those who are planning a pregnancy and clinical studies for pregnant women are generally not undertaken. As such, when pregnancies do occur in people under treatment for their MS, pregnancy outcomes for the baby and mother are of great interest to patients and their doctors to guide treatment decisions for future families. For this reason ‘pregnancy registries’ are often set up to record this data. Several recent papers have reported on pregnancy outcomes for interferon-beta 1b (Betaferon), teriflunomide (Aubagio) and natalizumab (Tysabri). " http://www.msra.org.au/new-reports-use-ms-medications-during-pregnancy
Personally, with our family history of Autism I wouldn't be take anything, I wouldn't recommend anyone continue taking most types of medications (regardless of if it was a DMD or not) IF they actually have that choice though but i'm not you and not in your situation (!) so i honestly feel you really need the support and guidance of both your neurologist and your OBGYN to help you work out what is the right thing for you!
Cheers.......JJ
There is a great group on Facebook "Just A Mom with MS"...plenty of women who have been pregnant or currently pregnant with MS that could give you their personal experience/perspective.
I think you need to discuss this with your neurologist. Or obstetrician.