Multiple sclerosis in pregnancy: relapses, treatment and the postnatal months

Multiple sclerosis is a condition of the brain and spinal cord in which the immune system damages the protective covering of nerves. The NHS describes the common symptoms as tiredness, visual disturbance, numbness and tingling, balance and coordination problems, muscle stiffness and spasm, bladder problems and difficulties with memory or concentration. It usually presents in young adulthood, so many women with MS are in their childbearing years.

The MS Trust explains that pregnancy is not automatically classed as high risk for women with MS, and that having MS does not increase the likelihood of miscarriage or birth defects. Pregnancy does not appear to cause long-term worsening of the condition.

The MS Trust notes that relapses fall markedly during the last trimester, months seven to nine, probably because the immune system is naturally dampened late in pregnancy. In the first three months after birth the relapse rate rose to almost one and a half times the rate before pregnancy in the figures it quotes.

This pattern is why planning matters. A relapse in the weeks after birth, when you are sleep-deprived and caring for a newborn, is harder to handle than one during pregnancy. Knowing how to contact the MS nurse and having a plan for treating a relapse reduces anxiety.

The NHS lists disease-modifying therapies as treatments that reduce how often relapses occur. According to the MS Trust, two of them are considered safe around conception and during pregnancy: the beta interferons and glatiramer acetate. Other therapies are usually stopped before conception, with the interval depending on the individual drug, and some require particular care because relapse risk can rise afterwards.

The MS Trust also says guidance recommends not delaying the start of a disease-modifying therapy until after family planning is complete, because early treatment helps prevent long-term disability. The right balance between treating the MS and planning a pregnancy is a joint decision with your neurologist.

• Ask your neurologist or MS nurse about timing before you stop contraception.

• Never stop a disease-modifying therapy on your own, because disease activity may return.

• Ask for a written plan covering what to do if you become pregnant unexpectedly.

• Ask which treatments are compatible with breastfeeding.

Most women with MS can be cared for in a standard maternity pathway, with the MS team in the background. It helps to tell your midwife about the diagnosis, your symptoms and any disabilities that affect mobility, balance, bladder or fatigue.

Common pregnancy effects such as tiredness, pelvic girdle discomfort and increased bladder frequency can overlap with MS symptoms, so a change that is new or persistent should be reported to the team rather than assumed to be pregnancy. Urinary tract infections in particular can trigger a temporary worsening of symptoms.

MS does not usually dictate the mode of birth. Vaginal delivery is expected for most women, and epidural or spinal anaesthesia is generally possible. If MS affects the muscles of the legs, pelvis or bladder, or if you have significant spasticity, discuss positioning and pain relief with the anaesthetist in advance.

Heat can temporarily worsen MS symptoms, so keeping the delivery room cool and drinking enough fluids can help. If an unusual new neurological symptom appears during labour, tell the team promptly.

The MS Trust says MS cannot be passed to a baby in breast milk and that having MS need not affect how you feed your baby. The two safe disease-modifying therapies are also appropriate while breastfeeding, so a return to treatment does not always mean stopping breastfeeding, although this is an individual conversation.

The MS Trust notes an increased risk of postnatal depression for both mothers and fathers with MS and strongly recommends planning a support network for the first year, including help with childcare and household tasks. Fatigue management, sleep protection and a plan for night feeds can make a real difference.

Contact your MS nurse or GP promptly for new or worsening symptoms lasting more than a day, such as sudden loss of vision, weakness or numbness, or difficulty walking. Call NHS 111 if you are unsure, and 999 for sudden severe weakness on one side, difficulty speaking or a severe headache with confusion. Tell the maternity team about any relapse, as treatment choices in pregnancy and breastfeeding differ.