Study investigates MS medication use in pregnant women
The number of people with Multiple Sclerosis (MS) has steadily increased over the past 50 years with women three times more likely to develop MS than men, resulting in a greater number of women of childbearing age presenting to neurologists in specialist clinics.
However, very limited information is available about the safety and use of disease-modifying treatments (DMTs) in these women during pregnancy. No clinical guidelines currently exist to assist health professionals in providing informed advice to women about their treatment.
It is the largest reported observational study of DMT exposure in pregnancy to date.
Multiple Sclerosis (MS) is an autoimmune neurological disease where the layers of membrane or the sheath covering the nerve fibres (myelin) are attacked by inflammatory cells of the body. Relapsing-remitting MS (RRMS) affects about 70% of people who are diagnosed with MS and usually starts in people aged in their 20s and 30s. Attacks, flares or relapses in RRMS result in local damage to the nerve cells, and their protective sheaths. A period of recovery follows (known as remission) when people with MS have few or no symptoms.
The study investigated the incidence of pregnancy in women with RRMS, their patterns of treatment with disease-modifying therapy (DMT) and their pregnancy outcomes (e.g. pre-term birth, spontaneous abortion, or birth).
Using the large international MSBase Registry, which collects information from people with MS over the long-term, data was analysed from 9,098 women aged 15-45 years. The researchers found that across 33 countries, there were in total 635 pregnancies (42%) that were conceived whilst women were on DMTs, with the average period of treatment 30 days.
Interestingly, the researchers found that during the 10-year study period, the number of pregnancies conceived with DMT had increased by 35%. The outcomes of pregnancy did not show any differences in spontaneous abortions, term or preterm births.
Dr Jokubaitis said the data suggested that women with more active disease are choosing to have children.
“Clinicians have become more comfortable keeping women on therapy until a pregnancy is confirmed, rather than withdrawing therapy once the decision has been made to start family planning,” she said.
“This is important as it recognises that the mother’s health is important. Keeping her healthy and relapse free in the period leading up to a confirmed pregnancy result is key to trying to prevent neurological decline. This also shows that clinical practice is starting to change, and move more in-line with pregnancy management in other neurological diseases such as epilepsy.
“Studies such as this open a window into clinical practice and pregnancy management in MS, something about which very little literature or guidance currently exists.”
The findings of this study, published in the journal Multiple Sclerosis and Related Disorders, have led to the development of a pregnancy register within the MSBase registry. It will capture foetal and neonatal outcomes of drug-exposed and non-exposed pregnancies in women with MS.
Dr Jokubaitis said, “whilst we cannot comment yet on the safety of these therapies in terms of foetal/neonatal outcomes, we can say that we do not see a significant pattern with regards to pre-term birth or miscarriage rates, which is reassuring. Hopefully with this register and with time, we may get a better understanding the safety of MS therapies, and their impact during in utero exposure.”
Nguyen, A et al. Incidence of pregnancy and disease-modifying therapy exposure trends in women with multiple sclerosis: A contemporary cohort study. Multiple Sclerosis and Related Disorders. 2019. 28: 235 – 243. https://doi.org/10.1016/j.msard.2019.01.003