Pregnancy and LEMS

Emily Malcolm, PhD avatar

by Emily Malcolm, PhD |

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Lambert-Eaton myasthenic syndrome (LEMS) is a rare autoimmune disease characterized by muscle weakness, among other symptoms. It is caused by the production of antibodies that mistakenly attack the point where nerve and muscle cells meet.

Can women with LEMS get pregnant?

There are no data indicating that women with LEMS cannot get pregnant. However, only a few accounts are known of LEMS patients becoming pregnant. This may be because the symptoms of the disease generally appear around age 40, after a woman’s prime years for conception.

What are the LEMS-related risks during pregnancy?

There are two cases in the literature of women with LEMS giving birth. In the first case, doctors had diagnosed the mother five years prior to the pregnancy. In the second case, the mother was diagnosed with LEMS as a result of muscle weakness that developed in the third trimester of the pregnancy. In both instances, the babies were healthy and had normal births.

LEMS can sometimes develop as a result of small-cell lung cancer (SCLC), so patients should undergo a cancer screening as soon as they receive a LEMS diagnosis. It is important to remember that many cancer treatments are not safe during pregnancy.

Can my baby inherit LEMS?

There are some genetic factors that can predispose people to develop LEMS, but researchers have not found a direct genetic cause for LEMS.

A risk with autoimmune diseases like LEMS is that the antibodies that the mother produces may affect the baby. However, in both published cases of LEMS pregnancies, the baby was not affected.

What precautions should I take during pregnancy?

Recommendations for your pregnancy will depend on your symptoms and treatment plan. Talk to your doctor about any special precautions. If your primary care physician is not an obstetrician, they may need to consult with your obstetrician about your specific needs. Because LEMS is a rare disease, not every physician will have experience with treating it.

It’s a good idea to keep a detailed log of your symptoms so that your doctor can spot any problems. Discuss with your care team whether your medications need to change during or after your pregnancy.

What happens after the baby is born?

You will have to discuss your medications with your care team, and determine whether breastfeeding your baby will be safe.

In the two published cases, LEMS did not affect the baby. However, your doctor may want to keep your baby under observation for several days after delivery. They may also want conduct more frequent newborn checkups than usual.


Last updated: May 4, 2020


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