Thrombocytopenia in pregnancy: what should you know about low platelets?

Pregnancy thrombocytopenia is a pregnancy complication of your low platelet count. Platelets are cells that clot blood and help slow bleeding. When a blood vessel in your body is damaged, platelets bind together at that site to clot the blood.

Thrombocytopenia is a low count of platelets in the blood. About 10% of pregnant women will develop low platelets during pregnancy. There are several potential causes, but by far the most common cause is a benign condition called gestational thrombocytopenia.

If your platelet count drops enough to be considered thrombocytopenia, your obstetrician will carefully monitor your blood values ​​and take extra precautions as needed. Fortunately, if the cause is gestational thrombocytopenia, the condition is usually mild and usually resolves on its own after birth.

Thrombocytopenia symptoms

Many pregnant women with thrombocytopenia have no symptoms.

If you experience the following symptoms during pregnancy, your low platelets may be due to other reasons:

  • Bleeding gums (such as when flossing or brushing)
  • blood in urine or stool
  • easy bruising
  • fatigue
  • nosebleed
  • petechiae (small red spots that indicate bleeding under the skin)

when to see a doctor

If you develop any new symptoms during your pregnancy that worry you, see your doctor. Uncontrolled bleeding is an emergency and requires immediate treatment.

Thrombocytopenia in pregnancy

Many women experience low platelet counts during pregnancy due to changes that occur in the body. The number of platelets in the blood naturally decreases throughout pregnancy.

It is estimated that gestational thrombocytopenia occurs in 7% to 12% of pregnant women in the United States. After anemia, gestational thrombocytopenia is the second most common hematologic abnormality during pregnancy.

In people with gestational thrombocytopenia, platelet counts always return to normal within a few weeks of delivery.

What is a normal platelet count?

A normal platelet count ranges from 150,000 to 450,000 platelets per microliter of blood. You are considered to have thrombocytopenia when your platelet count falls below 150,000 platelets.

A 2018 study monitored platelet counts in pregnant women aged 15 to 44 and compared them to non-pregnant women of the same age. The researchers found that platelet counts naturally declined in pregnant participants as the pregnancy progressed.

The average platelet count in the first trimester was 251,000 platelets per microliter of blood, compared with 273,000 platelets in non-pregnant women. The level continued to drop, with the mean platelet count at birth being 217,000 platelets.

Of the 4,568 pregnant participants in the study, 10 percent were diagnosed with gestational thrombocytopenia and had a platelet count of less than 150,000 at birth. Women who experience gestational thrombocytopenia are more likely to experience the condition again in subsequent pregnancies.

Overview of Platelet Disorders

Pregnancy platelet connection

During pregnancy, your body produces more plasma. This increases blood volume and causes blood thinning. This means that you have the same number of platelet cells in a larger volume of blood. As a result, the platelet count per microliter of blood drops.

In addition to the natural blood thinning process, your platelet count may also decrease as they are destroyed. During pregnancy, your spleen enlarges due to increased blood volume. When an enlarged spleen filters your blood, it may destroy platelet cells at a higher rate.

In rare cases, a severe lack of folic acid in the diet can also cause thrombocytopenia. Because of prenatal vitamins, this isn’t usually a problem for American women.

Gestational thrombocytopenia is thought to be only a modest exaggeration of the normal decline in platelets during normal pregnancy. It does not cause bleeding problems and generally does not increase the risk of pregnancy complications.

Folic acid and pregnancy


No test can diagnose thrombocytopenia in pregnancy, so your doctor will work with you to rule out other causes of thrombocytopenia before diagnosing you.

It is estimated that 70% to 80% of gestational thrombocytopenia is caused by gestational thrombocytopenia.

If your platelet count falls below 100,000 platelets per microliter of blood, your doctor may order additional tests, as this level indicates another cause of your thrombocytopenia. If your platelet level is below 40,000 to 50,000 platelets, a diagnosis of gestational thrombocytopenia is unlikely.

Thrombocytopenia is generally considered pregnancy-specific when you have never experienced low platelets in the past (except during previous pregnancies) and the baby is not affected. Gestational thrombocytopenia usually begins in the second trimester and worsens as the pregnancy progresses. It will then go away on its own within one to two months after delivery.

The second most common cause of thrombocytopenia in pregnancy is immune thrombocytopenia (ITP), which can occur at any time and affects approximately 3% of pregnant women. Once the platelet count falls below 100,000 platelets, ITP is more likely to be the cause.

Other possible causes of thrombocytopenia

  • alcohol abuse
  • anemia
  • Bacterial infections
  • cancer
  • chemotherapy
  • drug
  • Viral infection
  • immune thrombocytopenia
  • hemolytic uremic syndrome
  • preeclampsia
  • thrombotic thrombocytopenic purpura


Once your doctor has diagnosed you with gestational thrombocytopenia, the two of you will discuss what precautions, if any, you need to take for the remainder of your pregnancy and the postpartum period.

monitoring and treatment

To monitor your platelet levels, your doctor will order a complete blood count (CBC) blood test, which includes measuring your platelet count. The frequency of testing will depend on your platelet levels and the symptoms you are experiencing.

With gestational thrombocytopenia, bleeding problems rarely, if ever, occur. However, it is important to measure your platelet count during labor because if platelets drop below 100,000, there may be another reason for a low platelet count. In this case, extra precautions may be needed to prevent bleeding.

Everything you need to know about childbirth


Thrombocytopenia during pregnancy may be caused by preeclampsia. Preeclampsia involves high blood pressure and signs of organ damage during pregnancy. It usually happens after week 20. Preeclampsia can lead to low platelet counts, accounting for about 21% of cases of thrombocytopenia at birth.

Occasionally, preeclampsia can also occur after childbirth. It usually has no symptoms at all, but you may notice sudden weight gain or swelling in your hands and feet. Pre-eclampsia needs to be closely monitored because severe untreated cases can lead to eclampsia (a type of epilepsy) or HELLP syndrome (a multi-organ syndrome).

For high-risk groups, daily low-dose aspirin is recommended to help prevent preeclampsia and its associated complications. Treatment should start between 12 and 28 weeks of pregnancy, preferably before 16 weeks.

Once this happens, the only cure is childbirth. If it happens after delivery, you will be taken to hospital for treatment and observation. Treatment usually includes a drug called magnesium sulfate.

have high blood pressure

Frequently Asked Questions

Can gestational thrombocytopenia be prevented?

No, gestational thrombocytopenia is just an exaggeration of the normal drop in platelets during pregnancy. Women who had gestational thrombocytopenia in one pregnancy were more likely to develop the disorder in subsequent pregnancies, but the condition was also benign in subsequent pregnancies.

What causes thrombocytopenia in pregnancy?

Gestational thrombocytopenia is caused by natural changes that occur in the body during pregnancy. When you are pregnant, your body increases blood volume, which causes blood thinning. This happens when the plasma increases while the platelet count remains the same. This results in a low platelet count per microliter of blood.

In addition to hemodilution, increased blood volume can also cause the spleen to enlarge. When this happens, the enlarged spleen traps and destroys more platelet cells during the filtration process.

How is thrombocytopenia in pregnancy treated?

There is no specific treatment for gestational thrombocytopenia, nor does it require any treatment, as it does not produce bleeding problems or any other problems with labor, delivery, or the baby.

Does gestational thrombocytopenia affect the baby?

No, gestational thrombocytopenia does not pose a risk to you or your baby.


Pregnancy thrombocytopenia is usually a natural phenomenon of pregnancy. Your doctor will monitor your platelets during your pregnancy and recommend any treatment needed. If your platelet count is below 80,000 per microliter of blood, your thrombocytopenia may be due to other causes.

VigorTip words

Pregnancy is a time of rapid change and can be fraught with uncertainty. Talk to your doctor if you notice symptoms of thrombocytopenia, such as bleeding gums or frequent bruising. Being diagnosed with gestational thrombocytopenia can be scary, but keep in mind that most women experience a temporary low platelet count towards the end of their pregnancy. It is helpful to remember that gestational thrombocytopenia is usually mild and resolves on its own after delivery.