NASHVILLE -- Questions are now being raised about recent recommendations that clinicians counsel their female multiple sclerosis patients to stop disease-modifying treatments (DMTs) before planned pregnancies and to discontinue them during pregnancy unless their MS relapse risk is too great.
The by the American Academy of Neurology (AAN) note that "Clinicians should discontinue DMTs during pregnancy if accidental exposure occurs, unless the risk of MS activity during pregnancy outweighs the risk associated with the specific DMT during pregnancy" (Level B recommendation).
While the AAN writing committee noted that "each DMT has a separate FDA statement about pregnancy associated risks," the group made no effort to clarify the relative risk of the 17 approved DMTs with regard to pregnancy.
But speaking here at the , Patricia K. Coyle, MD, of Stony Brook University Medical Center in New York, said it is clear that some DMTs are not teratogenic, and there is good evidence that others pose very little risk to the developing fetus.
She told attendees that, by failing to stratify DMTs by their individual risks, the AAN recommendations could put a large number of women with the disease at unnecessary risk.
"We need at least 1,000 unit pregnancy exposures to comment on whether a drug is safe or not," she said. "We have that with glatiramer acetate [GA] -- thousands of exposures during pregnancy -- and with the interferon betas -- thousands of exposures. They are safe. You need no washout. You can continue the interferon or GA until you get pregnant. You could even most likely use them during pregnancy and breast feeding."
She noted that some experts have said pregnancy washouts are not needed for women taking dimethyl fumarate (Tecfidera) and natalizumab (Tysabri), although she added that the data is not as strong for these drugs.
"And some experts even recommend that you could consider using natalizumab during pregnancy in highly active patients based on studies that have indicated issues withdrawing patients," she said. "We know that washouts of natalizumab and fingolimod [Gilenya], in particular, have been associated with increased rates of MS attacks during pregnancy as well as the post-partum period. Both of these are DMTs that carry a risk of rebound in activity in a minority of individuals."
In a review of DMT use in pregnancy published in 2016, Coyle noted that none of the oral DMTs are recommended for use while pregnant or breastfeeding.