Inherited Platelet Disorders


The information provided below is for readers based in the United States of America. Readers outside of the United States of America should seek the information from local sources.

What are inherited platelet disorders?

Platelets, also called thrombocytes, are cell-like entities that circulate in the blood and are necessary to the process of blood clot formation to stop bleeding. They work with various proteins, called clotting factors, or coagulation factors, that are present in the blood or along the wall of blood vessels. In the process of clot formation, platelets aggregate, or stick together, to form a kind of plug to help with blood vessel healing. Platelet function depends on the presence of certain proteins on the surface of the membrane that surrounds the platelet, which help attach the membrane to other platelets and to certain clotting factors made outside the platelet, and also on packets (granules) of chemicals that are stored inside the platelet and are released during the clotting process. Manufacture of the granules and their contents, and platelet surface proteins all depend on genes that you inherit from your parents. Consequently, they are vulnerable to abnormalities in the genetic information, which can result in problems in the bodys ability to form clots, problems that in some cases can be made worse by changes that occur during pregnancy.

Genetic problems involving the granules inside the platelets are called storage pool disorders, whereas there are two main categories of platelet surface protein disorders. One such disorder, called Glanzmann thrombasthenia, results from a problem with a complex of surface proteins called glycoprotein IIb-IIIa. Another inherited surface protein disorder is called Bernard-Soulier syndrome, which is a problem with a surface protein called glycoprotein Ib. The role of this protein is to bind with a very large protein called von Willebrand factor (vWF), which is also produced in platelets and problems with vWF constitute the most common blood clotting disorder. However, since vWF also is produced outside of platelets and circulates in the blood, vWF disorders (called von Willebrand disease) are discussed in a separate consumer report. Although Bernard-Soulier syndrome, Glanzmann thrombasthenia, and storage pool disorders are much less common than von Willebrand disease, we are reporting on them here because they are typically more challenging to manage in pregnant women.

How common are inherited platelet disorders during pregnancy?

These conditions are not so common overall. Glanzmann thrombasthenia, for instance, happens in less than 1 per 1 million people. However, it strikes females a little more often than males, unlike certain blood clotting deficiencies such as hemophilia A and hemophilia B, which affect mostly males. It is also found more often in certain ethnic groups, such as southern Indians, French Romany, Iraqi Jews, and certain Arab populations, such as Palestinians. Similarly, Bernard-Soulier syndrome also is thought to affect just under 1 per 1 million people, but the ethnicities affected most commonly are people of white European and Japanese descent.

How are inherited platelet disorders diagnosed?

Inherited platelet disorders are diagnosed initially with a complete blood count (CBC), coagulation tests called the prothrombin time (PT) and the activated partial thromboplastin time (aPTT), analysis of platelet function, and examination of your blood under a microscope to look for particular types of cells. Testing continues with a technique called flow cytometry and analysis of mutations of your genes.

Do inherited platelet disorders cause problems during pregnancy?

These conditions put you at risk of hemorrhage and the risk increases during pregnancy as a result of changes in the blood.

Do inherited platelet disorders cause problems for the baby?

If you hemorrhage on account of the inherited platelet disorder, this can put the health and life of the developing baby at risk by causing a reduction of blood circulation through the uterus and placenta.

What to consider about taking medications when you are pregnant or breastfeeding:

  • The risks to yourself and your baby if you do not treat the inherited platelet disorder
  • The risks and benefits of each medication you use when you are pregnant
  • The risks and benefits of each medication you use when you are breastfeeding

What should I know about using medication to treat my inherited platelet disorder during pregnancy?

The severity of these conditions varies greatly among patients, and not everyone requires treatment. For those requiring treatment, medications that are useful consist of the clotting factor thrombin to stop bleeding, a genetically engineered clotting factor called recombinant factor VIIa, and what doctors call antifibrinolytic therapy, which consists of an agent called tranexamic acid. Studies suggest that tranexamic acid is safe during pregnancy. As for the clotting factors, these were never thought to be dangerous to the developing baby, since they do not cross through the placenta.

Who should NOT stop taking medication for an inherited platelet disorder during pregnancy?

Many women do not require treatment. If you experience a bleeding episode, however, it is vital to accept medical treatment, such as clotting factors and tranexamic acid.

What should I know about choosing a medication for my inherited platelet disorder during pregnancy?

You may find Pregistrys expert reports about the individual medications used to treat inherited platelet disorder here. Additional information can also be found in the sources listed at the end of this report.

What should I know about taking a medication for my inherited platelet disorder when I am breastfeeding?

Clotting factors and antifibrinolytics therapy in the mother are not thought to pose a risk to the nursing infant.

What alternative therapies besides medications can I use to treat inherited platelet disorders during pregnancy?

The standard treatment for attacks of any of these inherited platelet disorders actually is not drug treatment, but the infusion of platelets into the mothers blood, if her symptoms reach a certain severity level. A long-term treatment, which actually cures the condition, is a hematopoietic stem cell transplant. This is not something that can be done during pregnancy, but it is an option prior to becoming pregnant. Although currently experimental, gene therapy is on the horizon as another route to curing these conditions.

What can I do for myself and my baby when I have an inherited platelet disorder during pregnancy?

Cooperate with your physicians. Keep in mind that what benefits your health and safety also benefits the health of your developing baby or nursing infant.

Resources for inherited platelet disorders in pregnancy:

For more information about inherited platelet disorders during and after pregnancy, contact (800-994-9662 [TDD: 888-220-5446]) or check the following links:

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Last Updated: 11-03-2020
General information

It is very common for women to worry about having a miscarriage or giving birth to a child with a birth defect while they are pregnant. Many decisions that women make about their health during pregnancy are made with these concerns in mind.

For many women these concerns are very real. As many as 1 in 5 pregnancies end in a miscarriage, and 1 in 33 babies are born with a birth defect. These rates are considered the background population risk, which means they do not take into consideration anything about the health of the mom, the medications she is taking, or the family history of the mom or the baby’s dad. A number of different things can increase these risks, including taking certain medications during pregnancy.

It is known that most medications, including over-the-counter medications, taken during pregnancy do get passed on to the baby. Fortunately, most medicines are not harmful to the baby and can be safely taken during pregnancy. But there are some that are known to be harmful to a baby’s normal development and growth, especially when they are taken during certain times of the pregnancy. Because of this, it is important to talk with your doctor or midwife about any medications you are taking, ideally before you even try to get pregnant.

If a doctor other than the one caring for your pregnancy recommends that you start a new medicine while you are pregnant, it is important that you let them know you are pregnant.

If you do need to take a new medication while pregnant, it is important to discuss the possible risks the medicine may pose on your pregnancy with your doctor or midwife. They can help you understand the benefits and the risks of taking the medicine.

Ultimately, the decision to start, stop, or change medications during pregnancy is up to you to make, along with input from your doctor or midwife. If you do take medications during pregnancy, be sure to keep track of all the medications you are taking.