Gestational thrombocytopenia (low platelet count) is common during pregnancy and usually doesn’t cause complications. But there could be other causes of thrombocytopenia during pregnancy that may require treatment.

If you have thrombocytopenia, it means your platelet count is low. Platelets are blood components that help with clotting.

A decrease in platelet levels is common during pregnancy. This condition, known as gestational thrombocytopenia (GT), is often mild and doesn’t cause complications.

This article explores the causes, diagnosis, and treatment of low platelets during pregnancy.

GT is fairly common during pregnancy. For example, the authors of a 2021 study found that GT occurred in 12% of the 3,691 pregnancies included in the study. The authors also cited previous research indicating that GT affects approximately 10% of all pregnancies, which amounts to around 10 million pregnancies globally each year.

Although what precisely causes GT is unknown, it’s likely due to typical physiological changes that occur during pregnancy to accommodate a developing fetus.

According to a 2017 review of scientific literature, the total volume of blood circulating in your body increases by 30–50% during pregnancy. As a result, your blood is more diluted than usual. This can lower your platelet count. The authors of a 2022 research review concur, noting that pregnant people tend to have lower platelet counts, on average, than the general population.

It’s unclear why some pregnant people develop GT, while others do not.

What else can cause thrombocytopenia in pregnancy?

According to research summarized in the 2022 research review above, around 75% of pregnant people who experience thrombocytopenia have GT. The remaining cases could be a side effect of another condition that may or may not be linked to pregnancy.

Other causes of thrombocytopenia in pregnancy include:

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Most of the time, GT doesn’t cause noticeable symptoms. Many symptoms linked to GT are also typical during pregnancy.

Some symptoms of GT include:

You should mention the above symptoms to your doctor, even if they’re mild. Your doctor might want to order some tests to check for GT or another condition.

There’s no specific diagnostic test for GT. While a complete blood count (CBC) can identify platelet levels that fall below the threshold for thrombocytopenia, it does not explain the cause.

To diagnose GT, your doctor will rule out other potential causes of thrombocytopenia during pregnancy by asking about your symptoms, medical history, and family history. They’ll also conduct a physical examination.

Besides a CBC and a blood smear, your doctor might order other tests to check for an infection or evaluate your liver function.

As described above, GT is likely due to physiological changes that naturally occur during pregnancy.

ITP is another potential cause of low platelet counts in pregnant people. Although it is not linked to pregnancy, doctors sometimes accidentally discover it during routine checkups.

Like GT, ITP doesn’t always cause symptoms. And when symptoms do occur, they can resemble those of GT.

The following key differences allow doctors to tell the two conditions apart:

Gestational thrombocytopenia (GT)Immune thrombocytopenic purpura (ITP)
– more likely to be mild
– most noticeable in the third trimester
– improves rapidly after delivery
– more likely to be moderate
– noticeable anytime during pregnancy
– does not improve after delivery

Treatment isn’t usually necessary for GT. Your doctor will likely continue monitoring your platelet levels every 2–4 weeks as your pregnancy progresses.

Most people who have GT can have a vaginal birth. But if your platelet count is below 20,000 per microliter, your obstetrician might recommend avoiding instruments such as vacuums and forceps during delivery.

Thrombocytopenia usually goes away on its own within 6 weeks of delivery. If you become pregnant again, though, you’ll be at an increased risk of developing GT.

When thrombocytopenia is a symptom of another condition, you’ll usually require treatment. For example, treatment for ITP includes intravenous immunoglobulin (IVIG) and corticosteroids.

GT doesn’t usually cause pregnancy complications. Research summarized in the above 2022 research review suggests that GT isn’t likely to cause thrombocytopenia in infants, either.

You might have to undergo extra monitoring during your pregnancy, particularly in the third trimester or if you have other complications.

Following delivery, your healthcare team will most likely conduct several platelet count checkups for both you and your baby.

It’s not always possible to prevent thrombocytopenia in pregnancy. With that said, there may be a link between low platelet counts and a lack of folic acid in the bloodstream, so it’s important that you take a prenatal vitamin with folic acid.

In addition, infections can deplete your platelets. It’s important to do your best to support your health by maintaining good hygiene, getting tested for sexually transmitted infections (STIs), and ensuring your vaccines are up to date.

Mild thrombocytopenia is common during pregnancy. Most of the time, it doesn’t cause symptoms or complications for the birthing parent or baby.

GT doesn’t usually require treatment, and it shouldn’t change much about your birth plan. Still, your doctor might recommend additional monitoring of your platelet count, particularly in the third trimester.