What is gestational thrombocytopenia (GT)?

Thrombocytopenia occurs when the number of platelets in the blood falls below a certain level. In gestational thrombocytopenia (GT), your pregnancy causes this decrease. GT is benign, usually asymptomatic and almost always resolves itself after delivery.

To understand GT, it helps to learn about platelets and how they work in the body.

Platelets are small, plate-shaped blood cells produced in your bone marrow. When a blood vessel is damaged—for example, if you cut your arm—platelets stick together to form a clot and stop the bleeding. Needless to say, they are quite important. When you don’t have enough platelets, you will bruise and bleed more easily.

People usually have between 150,000 and 400,000 platelets per microliter of blood. If that number falls below 150,000, it means you have thrombocytopenia, or a low platelet count. If you are pregnant and this happens, you probably have GT.

Almost all cases of GT are mild, with platelet counts ranging between 100,000 and 150,000. On the rare occasion that they drop lower, another medical problem is likely.

Between 7 and 12% of pregnancies are affected by GT, with women carrying twins and triplets at higher risk. If you have the condition once, you are 14 times more likely to develop it in a later pregnancy.

What causes low platelets during pregnancy?

Research showsOpens a new window that the platelet count is typically lower in pregnant women and continues to decline during pregnancy. But when that number drops abnormally low, there are several possible causes.

Gestational thrombocytopenia is by far the most common cause of low platelets in pregnancy. Experts aren’t entirely sure what causes GT, but hemodilution may play a role.

Here’s how: When you’re pregnant, your blood volume increases to support your baby’s growth. (Essentially, you get more plasma.) But certain cells in your blood, including platelets, may not grow at the same rate, leading to a deficit.

Another potential factor in GT: faster breakdown of platelets. Normally, the lifespan of platelets is about a week. But the lifespan of platelets is likely to be shorter during pregnancy because of the changes your body is going through.

So when your platelets break down faster and your body doesn’t replace them as quickly, it leads to a lower than normal platelet count.

immune thrombocytopenia (ITP) is the second biggest cause of low platelets in pregnant women. However, it is not caused by pregnancy. Instead, it is a malfunction of the immune system. ITP causes increased bleeding and bruising, as well as the formation of purple spots on your skin.

Other medical conditions cause low platelets in pregnancy less than 1% of the time. Some problems are specific to pregnancy, while others are different conditions. These include:

What symptoms can I experience if I have low platelets in pregnancy?

Most people with GT have no symptoms. If you experience symptoms like nosebleeds or excessive bruising, you probably have another condition.

Because it is usually asymptomatic, many women are diagnosed with GT only after a routine test called a complete blood count (CBC), often in the second or third trimester. Some women, however, won’t find out until they give birth.

There is no specific test to diagnose GT, nor a test to distinguish between GT and other causes of low platelets. So, to diagnose GT, your doctor must rule out other medical conditions.

Generally speaking, you will be diagnosed with GT if your platelet count is between 100,000 and 150,000, if you are not bleeding or bruising profusely and your CBC shows no associated abnormalities.

If your platelet count drops below 100,000, there is usually a reason other than GT. In this case, your provider will investigate ITP and other potential causes.

What are the treatment options for gestational thrombocytopenia?

You won’t need GT treatment while you’re pregnant, and you probably won’t need to do anything different when it comes to your prenatal care.

The condition usually clears up on its own within a month or two after delivery.

An exception is the platelet count. If you were diagnosed with GT before delivery, your doctor will likely check your platelets several times until your due date. That number will be checked again during delivery, and again one or two months after delivery to make sure you are clear.

If your platelet count does not return to normal after giving birth, you may not have GT after all. Instead, another condition may be the culprit – most commonly, ITP.

Rarely, while you are pregnant, your doctor may diagnose another cause of low platelets, such as lupus or severe liver disease. If this is the case, you will be assessed and treated for the condition.

Will low platelets affect my baby?

Gestational thrombocytopenia will not harm your baby. And if you’ve been diagnosed with GT, the risk of your baby developing low platelets is low. Research suggestsOpens a new window less than 1% of infants will have a low platelet count at birth.

Breastfeeding is also safe. You can go ahead and breastfeed without any problems.

If you have a very low platelet count at the time of delivery, there is a chance you won’t be able to get an epidural. But your provider will walk you through your options and it won’t affect your baby.

When to call your doctor

Since you usually won’t have symptoms if you have GT, you probably won’t need to talk to your doctor about it outside of regular prenatal visits. (Then again, you might not even know you have it.)

The good news is that even though your platelets are low, they are probably functioning normally – which is why most pregnant women have no symptoms and are not at increased risk of bleeding or bleeding during labour.

However, new, sudden, unusual and serious symptoms of any kind are always a good reason to call your gynecologist or midwife. And seek medical help immediately if you experience emergency symptoms such as vaginal bleeding, difficulty breathing, or intense pain or cramps.