Autoimmune Disorders During Pregnancy

ByLara A. Friel, MD, PhD, University of Texas Health Medical School at Houston, McGovern Medical School

Last full review/revision March 2019 by Lara A. Friel, MD, PhD 

 

NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version

 

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Autoimmune disorders, including Graves disease, are more common among women, particularly pregnant women. The abnormal antibodies produced in autoimmune disorders can cross the placenta and cause problems in the fetus. Pregnancy affects different autoimmune disorders in different ways.

 

Antiphospholipid Syndrome

Antiphospholipid syndrome, which causes blood clots to form too easily or excessively, can cause the following during pregnancy:

• A miscarriage or stillbirth
  
• High blood pressure or preeclampsia (a type of high blood pressure that occurs during pregnancy)
  
• A fetus that may not grow as expected (small for gestational age)
  

To diagnose antiphospholipid syndrome, doctors do the following:

• Ask women whether they have had any unexplained stillbirths or miscarriages, premature births, or problems with blood clots
  
• Do blood tests to detect antiphospholipid antibodies on at least two separate occasions
  

Based on this information, doctors can diagnose antiphospholipid syndrome.

If a woman has antiphospholipid syndrome, she is usually treated with anticoagulants and with low-dose aspirin during pregnancy and for 6 weeks after delivery. Such treatment can prevent blood clots and pregnancy complications from developing.

Immune Thrombocytopenia (ITP)

In immune thrombocytopenia, antibodies decrease the number of platelets (also called thrombocytes) in the bloodstream. Platelets are cell-like particles that help in the clotting process. Too few platelets (thrombocytopenia) can cause excessive bleeding in pregnant women and their babies.

If not treated during pregnancy, immune thrombocytopenia tends to become more severe.

The antibodies that cause the disorder may cross the placenta to the fetus. However, they rarely affect the platelet count in the fetus.

The fetus can usually be delivered vaginally.

 

Treatment

• Corticosteroids
  
• Sometimes immune globulin, given intravenously
  

Corticosteroids, usually prednisone given by mouth, can increase the number (count) of platelets and thus improve blood clotting in pregnant women with immune thrombocytopenia. However, this improvement lasts in only about half of women. Also, prednisone increases the risk that the fetus will not grow as much as expected or will be born prematurely.

Women who have a dangerously low platelet count may be given high doses of immune globulin intravenously shortly before delivery. Immune globulin (antibodies obtained from the blood of people with a normal immune system) temporarily increases the platelet count and improves blood clotting.

As a result, labor can proceed safely, and women can have a vaginal delivery without uncontrolled bleeding.

Pregnant women are given platelet transfusions only when the platelet count is so low that severe bleeding may occur or sometimes when cesarean delivery is needed.

Rarely, when the platelet count remains dangerously low despite treatment, doctors remove the spleen, which normally traps and destroys old blood cells and platelets. The best time for this surgery is during the 2nd trimester.

Myasthenia Gravis

Myasthenia gravis, which causes muscle weakness, does not usually cause serious or permanent complications during pregnancy. However, pregnant women may have more episodes of weakness.

Thus, they may need to take higher doses of the drugs (such as neostigmine) used to treat the disorder. These drugs can have side effects such as abdominal pain, diarrhea, vomiting, and increasing weakness. If these drugs are ineffective, women may be given corticosteroids or drugs that suppress the immune system (immunosuppressants).

Some drugs that are commonly used during pregnancy, such as magnesium, can make the weakness caused by myasthenia gravis worse. So women who have myasthenia gravis must make sure their doctors know they have it.

Very rarely during labor, women who have myasthenia gravis need help with breathing (assisted ventilation).

The antibodies that cause this disorder can cross the placenta. So about one of five babies born to women with myasthenia gravis is born with the disorder. However, the resulting muscle weakness in the baby is usually temporary because the antibodies from the mother gradually disappear and the baby does not produce antibodies of this type.

Rheumatoid Arthritis

Rheumatoid arthritis may develop during pregnancy or, even more often, shortly after delivery. If rheumatoid arthritis is present before pregnancy, it may temporarily subside during pregnancy.

If arthritis has damaged the hip joints or lower (lumbar) spine, delivery may be difficult for the woman, but this disorder does not affect the fetus. The symptoms of rheumatoid arthritis may lessen during pregnancy, but they usually return to their original level after pregnancy.

If a flare-up occurs during pregnancy, it is treated with prednisone (a corticosteroid). If prednisone is ineffective, a drug that suppresses the immune system (immunosuppressant) may be used.

Systemic Lupus Erythematosus (Lupus)

Lupus may appear for the first time, worsen, or become less severe during pregnancy. How a pregnancy affects the course of lupus cannot be predicted, but the most common time for flare-ups is immediately after delivery.

Women who develop lupus often have a history of repeated miscarriages, fetuses that do not grow as much as expected (small for gestational age), and preterm delivery. If women have complications due to lupus (such as kidney damage or high blood pressure), the risk of death for the fetus or newborn and for the woman is increased.

Problems related to lupus can be minimized if the following are done:

• Women wait to become pregnant until the disorder has been inactive for 6 months.
  
• The drug regimen has been adjusted to control lupus as well as possible.
  
• Blood pressure and kidney function are normal.
  

 

Lab Test

 

Antiphospholipid Antibodies

In pregnant women, lupus antibodies may cross the placenta to the fetus. As a result, the fetus may have a very slow heart rate, anemia, a low platelet count, or a low white blood cell count. However, these antibodies gradually disappear over several weeks after the baby is born, and the problems they cause resolve except for the slow heart rate.

If women with lupus were taking hydroxychloroquine before they became pregnant, they may take it throughout pregnancy. If flare-ups occur, women may need to take a low dose of prednisone (a corticosteroid) by mouth, another corticosteroid such as methylprednisolone, or a drug that suppresses the immune system (immunosuppressant) such as azathioprine.