Pregnant with Myasthenia Gravis? No Need to Panic

Myasthenia gravis (MG) is not exactly a common disease, but it affects young adult women most, so the question of pregnancy matters a lot. If you’re noticing any unusual breathing problems, get tested for myasthenia gravis. Do this before you’re thinking of getting knocked up. You should at least know what your health status is, so you can take the right precautions.

So what if the test shows you have MG? Pregnancy is stressful enough without the added burden of a chronic disease. Here’s the good news: If you take good care of your myasthenia gravis, you don’t have to be overly concerned about yourself and that bundle of joy you are carrying around with you.

The first thing to be aware of is that due to MG’s tendency to cause muscle weakness, your care team will think twice before prescribing magnesium sulfate. Pregnant women often take it for preterm labor or high blood pressure. Because it can cause added muscle weakness, it should be avoided in MG patients.

While most mothers see few problems during pregnancy, there are a couple of complications that may arise from MG:

  • Premature labor before 37 weeks. That’s because some drugs used to treat MG can induce labor. Adjusting dosage can be all that is needed to ensure going to full term.
  • Premature rupture of membranes containing amniotic fluid. While this is a rare complication, some women with MG elect to undergo caesarean sections as a preventative measure. Be aware of this option.
  • Difficult delivery. While MG does not affect the muscles of a woman’s uterus, it can weaken those core muscle groups needed for pushing. Women with MG are more likely to get tired during delivery, especially when labor is long. Not that you’ll fall asleep (imagine that!), but you might just become too exhausted to continue this important work. So there’s a likelihood that you will need forceps or vacuum assistance for delivery. Sometimes, your OB/GYN may decide a C-section is the safest route.

Another question bugging many expecting moms with MG:

Will I pass myasthenia gravis on to my child?

In most cases, the answer is no. Most women with myasthenia gravis have “acquired autoimmune MG,” which will not be passed on to their baby. However, there is a subset of patients with a congenital form of MG, and their children can potentially inherit it.

Congential myasthenia gravis occurs in between 12 and 20 percent of babies born to women with MG. This is caused by antibodies common to myasthenia gravis crossing from the placenta to the fetus. As a result, such babies may be born in a weakened state, have difficulty sucking, and sometimes have breathing problems. Others may be healthy immediately after birth, but develop congenital MG in early childhood.

So why shouldn’t I panic?

Such post-birth conditions are usually temporary and only last a few weeks. Most babies born to women with myasthenia gravis are healthy. As in all pregnancies, prenatal care is essential to ensure the best possible circumstances for mother and child. The most important factor is discussing your MG with your doctor, particularly if you have congenital MG or don’t know which type you have. This will help you reduce the risks of complications as early as possible. Particularly, you’ll want to adjust the dosage any medications you’re on to suit your exact situation and to lessen the likelihood of complications.

It’s no fun having something like MG. Being pregnant with myasthenia gravis doesn’t sound particularly appealing either, but the birth process can be managed, and your chances for a healthy child (and a happy mother) are intact.


Mothers with myasthenia gravis, what’s your story of giving birth? Did it go well? What advice would you give expecting mothers?

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