What are platelets?

Platelets are very small cells that are found in your blood. Their role is to prevent bleeding. If a blood vessel is injured, your platelets become sticky and clump together to form a blood clot at the damaged area. This stops it from continuing to bleed.

If your platelet count is low, you may not have enough platelets in your blood to stop bleeding. If you have very low platelets, you could start bleeding even without an injury. A low platelet count is also known as ‘thrombocytopenia’.

What does it mean to have low platelets during pregnancy?

Around 1 to 2 in every 20 people who are pregnant have low platelets.

Most of the time, this doesn’t cause problems — although the likelihood of complications depends on the cause and how low your platelet count is. Your doctor or midwife will arrange for you to have frequent blood tests to monitor your platelet count throughout your pregnancy if your platelets are low.

What causes low platelets during pregnancy?

There are many different causes of low platelets. Some only occur during pregnancy, while others can occur at any time.

Gestational thrombocytopenia

This refers to a low platelet count caused by the normal changes of pregnancy. It is the most common cause of low platelets in pregnancy. It is usually mild and goes away after your baby is born. It doesn’t usually cause any problems for you or your baby.

Immune thrombocytopenia (ITP)

This is an autoimmune problem, where your body makes antibodies that destroy your platelets. It can happen at any time, but it can get worse during pregnancy. It can cause very low platelets, which may put you and your baby at risk of bleeding.

HELLP syndrome

This is a serious pregnancy complication that can develop if you have pre-eclampsia. It can cause very low platelets, as well as other blood and liver problems.

Other causes

Other causes of low platelets can include:

• viruses
• not having enough vitamin B12 or folate in your diet
• some medications
• autoimmune health problems
• liver or spleen problems

What are the symptoms of low platelets?

You might not have any symptoms of low platelets.

If you do have symptoms, you may notice:

• bruises that appear on your skin without any injury
• bleeding from your nose, mouth or bottom
• it takes a long time for the bleeding to stop if you cut yourself

How is a low platelet count diagnosed?

A low platelet count is diagnosed from a blood test called a full blood count (FBC), also known as a full blood examination (FBE). Your doctor or midwife will offer you this blood test, as part of your routine antenatal tests in early pregnancy and again at 26 to 28 weeks.

If your platelets are low, you might have further blood tests to look for the cause.

When should I see my doctor?

It’s important to see your doctor or midwife when you are 6 to 8 weeks pregnant. They will arrange the tests you need, including blood tests, urine tests, ultrasound scans and others. If your blood test shows that you have a low platelet count, they will tell you how often it should be checked — this will depend on your stage of pregnancy and how low your platelets are.

If your doctor or midwife has told you that your platelets are unusually low and you experience any bleeding, see your doctor straight away.

What are the risks of low platelets during pregnancy and birth?

A low platelet count may increase your risk of a postpartum haemorrhage when you give birth. It may also increase your risk of bleeding around your spinal cord if you have an epidural or spinal anaesthetic. This is not usually a concern if your platelets are only mildly low.

If you have immune thrombocytopenia (ITP), your baby might also have low platelets. This increases your baby’s risk of bleeding, especially if they are born with a ventouse or forceps delivery.

Remember that gestational thrombocytopenia doesn’t usually cause any problems for you or your baby, so you should not be concerned if your doctor or midwife tells you that you have this condition.

How is a low platelet count treated during pregnancy and birth?

If your platelet count is only mildly low, you’ll be offered repeated blood tests to monitor it, but you probably won’t need any treatment.

If you have immune thrombocytopenia (ITP) or a very low platelet count, you will probably be referred to a specialist in blood problems, called a haematologist.

If your platelet count is very low, your doctor or midwife will recommend that you give birth in a hospital where a blood bank is available 24 hours a day. This is because you might need a blood transfusion if you lose a lot of blood when you give birth. They will also discuss with you if epidural anaesthesia is a safe pain relief option for you.

You might also be offered treatment to boost your platelet count before you give birth.

There are several treatments to increase your platelet count, including:

• steroid medicine
• intravenous immunoglobulin (also known as IVIG) — this is a dose of antibodies given into your vein
• a platelet transfusion

If your platelet count is very low, you might be advised to have your labour induced.

Can low platelets be prevented?

In general, there’s no evidence that you can prevent low platelets.

Although there are some things you can do to support your health during pregnancy such as:

• including vitamin B12 and folate (vitamin B9) in your diet
• avoiding medicines that can affect your platelets — ask your pharmacist if your medicines are safe to take while you’re pregnant
• avoiding behaviours that carry a risk of exposure to hepatitis C or HIV

Will low platelets get better after my baby is born?

It depends on what’s causing your low platelets. For example, if you have gestational thrombocytopenia, your platelets should go back to normal after your baby is born. However, if you have immune thrombocytopenia (ITP), your platelets might remain low and need further follow up with a specialist medical team.

Your doctor or midwife will recommend that you have another blood test a few months after your baby is born to check if your platelets have recovered. They will also advise on whether you need further medical care, based on these blood test results.

Resources and support

If you think you are bruising or bleeding easily, or if you’re concerned about your blood test results, talk to your doctor or midwife.

You can also call healthdirect on 1800 022 222 at any time to speak to a registered nurse (known as NURSE-ON-CALL in Victoria) for more information and advice.