Family Planning in Patients with Multiple Sclerosis

Multiple sclerosis (MS) mostly affects women during their reproductive years, making fertility and pregnancy management central concerns in long-term care. A narrative review by Trabaud et al. published in the Journal of Gynecology Obstetrics and Human Reproduction in October 2025 synthesizes a decade (2015-2025) of evidence on fertility, pregnancy, assisted reproductive technology (ART), and postpartum management in patients with MS. The findings reflect a clear shift away from historical assumptions that once discouraged pregnancy in this population.

Reassessing Pregnancy in MS

Pregnancy is now understood to temporarily reduce MS disease activity, with the strongest effect observed in the third trimester. Importantly, available evidence indicates that pregnancy doesn’t appear to accelerate long-term disability progression.

MS also doesn’t substantially increase the risk of adverse obstetric or neonatal outcomes, and most patients can expect normal fertility and successful pregnancies. As a result, current clinical priorities involve supporting patients’ reproductive goals through counseling and coordinated, individualized care, as emphasized in consensus guidelines like the 2018 ECTRIMS recommendations.

Fertility and MS Therapies

Current evidence indicates that MS doesn’t impair the ability to conceive or alter ovarian reserve. Most currently used MS disease-modifying therapies (DMTs) are not associated with meaningful long-term effects on gonadal function; treatments such as interferon-beta, glatiramer acetate, oral therapies, and monoclonal antibodies have not been associated with infertility.

One notable exception is hematopoietic stem cell transplantation (HSCT), which may be used as rescue therapy for aggressive MS. Conditioning regimens used for HSCT, including BEAM and cyclophosphamide-based protocols, are highly gonadotoxic and may lead to premature ovarian insufficiency. Early fertility preservation counseling is essential for these patients.

Contraceptive counseling is also critical for women receiving potentially teratogenic medications. For patients pursuing fertility treatment, larger cohort studies haven’t demonstrated an increased risk of MS relapse with ART, including cycles using GnRH agonist protocols.

Disease Activity During and After Pregnancy

The PRIMS study remains a landmark in understanding disease dynamics during pregnancy, demonstrating that relapse rates during late pregnancy were about 70% lower than during the year prior to conception. However, this protective effect is transient.

After childbirth, disease activity tends to increase again, particularly within the first 3-6 months postpartum. More recent studies suggest that this increase may be less pronounced than earlier reports indicated, likely reflecting better disease control with current treatment strategies.

Importantly, MS itself has not been linked to higher rates of miscarriage, congenital anomalies, stillbirth, or other major obstetric complications, and most women with MS have uncomplicated pregnancies and deliveries.

Managing Disease-Modifying Therapies

When it comes to therapeutic planning during pregnancy, current guidance recommends attempting conception during a period of stable disease, ideally after about a year without relapses and while using a pregnancy-compatible therapy if treatment is needed.

Injectable agents such as interferon-beta and glatiramer acetate have well-established safety data and are generally considered low risk in pregnancy. In patients with more active disease, anti-CD20 therapies like ocrelizumab, rituximab, and ofatumumab may be considered. Although these medications have not been linked to congenital abnormalities, placental transfer later in pregnancy may lead to temporary B-cell depletion in the newborn. If a relapse occurs during pregnancy, high-dose corticosteroids—most commonly intravenous methylprednisolone—are typically used as first-line treatment and appear safe when administered during the second or third trimester.

Postpartum Considerations

The postpartum period requires careful management because the risk of MS relapse increases after delivery. Factors associated with higher relapse risk include frequent disease activity before pregnancy, MRI lesions during pregnancy, younger maternal age (<35 years), and discontinuation of certain high-efficacy therapies, such as natalizumab or fingolimod.

Exclusive breastfeeding for the first two to three months may offer modest protection against disease activity and can be encouraged when disease is stable. Decisions about restarting therapy should be individualized.

If a relapse occurs postpartum, corticosteroids remain the primary treatment, and intravenous methylprednisolone is considered safe for breastfeeding patients and is commonly used for acute relapse management.

Toward Patient-Centered Care

The evolving evidence base around reproductive health in MS suggests a more optimistic and proactive approach. Multidisciplinary collaboration among neurologists, obstetricians, and reproductive specialists can help provide coordinated care for women with MS who are planning pregnancy or navigating the postpartum period.

For clinicians, the priority is no longer whether patients with MS should pursue pregnancy, but how best to support them through it with personalized, evidence-based care.

Reference:
Trabaud V, Zimmerman A, Gnisci A, Audoin B, Courbiere B. Multiple sclerosis, fertility, pregnancy, and assisted reproductive technology: Current knowledge. J Gynecol Obstet Hum Reprod. 2026;55(1):103061. doi:10.1016/j.jogoh.2025.103061