Family planning and multiple sclerosis - part 2: Does real-world practice align with Swedish treatment guidelines?

Background and objectives: Managing family planning and treatment in women with multiple sclerosis (MS) requires balancing disease control with medication safety. Despite guidelines, practice often adapts to individual needs, with clinicians adjusting disease-modifying therapies (DMTs) to protect maternal and fetal health. This study examines pregnancy-related MS treatment in Sweden. Methods: We identified 130 women (153 pregnancies) from a 2021 online MS questionnaire and linked responses to the Swedish MS register to capture DMT use during three periods: 25 weeks before conception, pregnancy (≈40 weeks), and 25 weeks postpartum. DMTs were classified as "accepted," "discontinuation recommended"-requiring monitoring, or "not recommended" in planned pregnancy. Results: Before conception, among 153 pregnancies, 26% involved DMTs considered acceptable before and during pregnancy, while 55% involved DMTs for which discontinuation before conception is recommended-of which rituximab accounted for nearly half of all pregnancies (47%, n = 72). Three percent were exposed to ´not recommended´ DMTs, and 16% had no prior treatment. Overall, 29% discontinued DMTs before or shortly after conception, while 58% (n = 88) had ongoing or recent treatment exposure, defined as treatment administered within 6 months before conception or, in a minority of cases, after conception. Among these, 50% (n = 77) involved rituximab-and 13% remained untreated. Postpartum, 58% resumed treatment, 3% remained under long-lasting DMT effects, and 39% did not initiate DMT, likely due to breastfeeding. Discussion: Overall, real-world practice in Sweden broadly aligns with national recommendations, with widespread use of rituximab before pregnancy reflecting its perceived safety and durable effect, alongside some individualized deviations from discontinuation guidance.