How Immune Thrombocytopenic Purpura Affects Pregnancy

Immune thrombocytopenic purpura (ITP) is a rare autoimmune bleeding disorder. The number of American adults diagnosed annually with this condition is roughly 3.3 per 100,000, according to the National Organization for Rare Disorders (NORD). About 9.5 per 100,000 people have the disorder at any given time.

ITP does not prevent anyone from getting pregnant and it may be diagnosed during pregnancy. This condition is diagnosed in approximately 1 out of every 1,000 to 10,000 pregnancies, according to the Platelet Disorder Support Association.

However, if you have ITP during pregnancy, you may need to be carefully monitored due to some additional concerns. Read on to learn more about this condition and how it may affect pregnancy.

What is ITP?

Immune thrombocytopenic purpura is a hematologic disorder characterized by a paucity of platelets, explained Kecia Gaither, M.D., board-certified in OB-GYN and maternal-fetal medicine and the director of perinatal services/maternal-fetal medicine at NYC Health + Hospitals/Lincoln in the Bronx, New York.

"Platelets are those essential elements in the blood that help to facilitate normal clotting. As a consequence, excessive bruising or protracted internal bleeding can occur," Gaither said.

There are two types of immune thrombocytopenic purpura, explained Monte Swarup, M.D., a board-certified OB-GYN and founder of HPD Rx, a health supplement company in Santa Monica, California. One is acute, and the other is chronic.

Acute

The most common form of this disorder, acute ITP usually occurs in children ages 2 to 6. About 40 percent of all patients diagnosed with ITP are children younger than 10. Symptoms often follow a viral illness and disappear within six months. Treatment is usually not needed, and recurrence is rare.

Chronic

Chronic ITP can happen to individuals of any age but is most common in adult women. Symptoms may last six months to many years. If you have chronic ITP, it requires consistent follow-up with a specialist.

Causes of ITP

Gaither explained that this condition is related to an autoimmune phenomenon, meaning the body attacks itself.

"The immune system's antibodies attack and destroy platelets, depleting their number in the body," she said.

Potential causes, according to Gaither, include:

• Other underlying autoimmune diseases, such as lupus
• Certain types of cancer
• Chronic infections, such as viruses that cause chicken pox, hepatitis C and AIDS
• Pregnancy
• Certain medications, such as NSAIDs (nonsteroidal anti-inflammatory drugs) or aspirin

Sometimes the cause is not found and the condition is considered idiopathic, meaning the reason is unknown.

Symptoms of ITP

"Platelets stop bleeding, so ITP concerns an increase in bleeding," Swarup said.

Additional symptoms to look for include:

• Bruises (large bruises without having an injury)
• Petechiae (small, red dots under the skin)
• Nosebleeds
• Mouth or gum bleeding
• Menstrual periods that are heavier than usual
• Urine, stools or vomit with blood
• Excessive bleeding when there is a head injury
• Prolonged bleeding with surgical procedures

To diagnose ITP, Swarup said your physician will do a full physical exam, review your medical history and current medications, and may do these tests:

• A complete blood count (CBC), which measures your platelet count
• A urine test to detect possible infections
• An antiplatelet antibody test, which is a special blood test
• A bone marrow aspiration, depending on the results of the other tests

ITP and pregnancy

There is no evidence to show whether ITP symptoms worsen or improve during pregnancy.

"Pregnancy is a particular cause for concern for women with ITP, as it can impact the fetus," Gaither said.

However, Swarup added, "only a very small percent of babies born to mothers with primary ITP have low platelets at birth."

Research does show that if you have had a previous baby with a low platelet count (thrombocytopenia), you are more likely to have another baby with a low platelet count.

Low platelet counts are a normal part of pregnancy, and Swarup said physicians often discover ITP during pregnancy. He advised that the main concerns if you are pregnant with ITP are increased bleeding at delivery and the inability to have an epidural during labor because of the risk of epidural hematoma, or bleeding between the inside of the skull and the outer covering of the brain.

The Platelet Disorder Support Association stresses that vaginal deliveries are safe if you have this disorder. However, it notes that most obstetricians prefer the platelet count to be above 50,000 in case a cesarean section is required.

To put this into perspective, a normal adult platelet count ranges from 150,000 to 450,000 platelets per microliter of blood. A platelet count of fewer than 150,000 platelets per microliter is considered lower than normal.

How is ITP treated?

Management of ITP depends very much on the severity of the symptoms. In general, Gaither said common treatments include:

• Corticosteroids such as prednisone, dexamethasone and methylprednisolone, which help prevent bleeding by reducing the rate of platelet destruction
• Intravenous immunoglobulin (IVIG) therapy, where plasma that contains antibodies is infused into your veins
• Thrombopoietin receptor agonists (TPO-RAs), such as rituximab, which target those immune cells that attack platelets
• Splenectomy, the removal of the spleen, may be indicated in rare circumstances for refractory ITP, a condition that doesn't respond to other treatments

Pregnant women with ITP need to discuss their current medications with their medical team to ensure their treatment is not contraindicated for pregnancy. The therapies used are the same as listed above, and several drugs are safe to use during pregnancy.

Whether you have ITP before pregnancy or find out you have it during pregnancy, clinicians indicate it is safe to continue your pregnancy with this platelet disorder.

The key guidance is you should receive close monitoring to ensure your condition is well controlled, the medications you are taking are safe during pregnancy and appropriate delivery plans are in place.