Introduction
Thrombocytopenia is the second most common type of blood disorder after anemia. During pregnancy, about 5 percent to 8 percent of women are diagnosed with a low blood platelet count (thrombocytopenia). It causes rare problems during pregnancy or birth, but it is good to be prepared for the potential effects.
What Is Thrombocytopenia?
Thrombocytopenia is a condition that causes a decrease in blood platelet count. Platelets are plate-shaped, colorless blood cells that circulate in the blood and help in blood clotting. When a blood vessel in the body is injured, a signal is sent to activate the platelets. The platelets then travel to the damaged area. After reaching the injured blood vessel, they clump and form a plug in the injured area and stop bleeding.
How Is Thrombocytopenia Classified?
Thrombocytopenia is classified into three types based on the number of platelets present in the blood.
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Mild - If 100,000 to 150,000 platelets are present per microliter of blood.
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Moderate - If 50,000 to 100,000 platelets are present per microliter of blood.
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Severe - If less than 50,000 platelets are present per microliter of blood.
During pregnancy, the platelet count is often less due to various reasons. However, if a woman has a platelet count below moderate, it can be due to non-pregnancy-related etiologies and underlying health conditions.
What Are the Causes of Thrombocytopenia During Pregnancy?
Thrombocytopenia can occur due to many reasons; some of the common reasons for low platelet count during pregnancy are as follows:
1) Gestational Thrombocytopenia - This is a benign condition and the most common cause of low platelets during pregnancy. It accounts for 70 to 80 percent of the low platelet count during pregnancy. Gestational thrombocytopenia usually occurs during the third trimester of pregnancy. The exact cause for a reduction in platelet count is unknown, but it is believed as a result of the increased blood volume as the pregnancy progresses to full term. During the third trimester, the blood plasma will increase by almost 50 percent. As plasma volume increases, the platelets are diluted, which means there will be only fewer platelets present per milliliter of blood. This will return to normal levels after the delivery.
2) Preeclampsia - This is a condition that occurs with increased blood pressure and protein in the urine. Low platelets are often seen in the third trimester, associated with a more acute form of preeclampsia known as HELLP (hemolysis, elevated liver enzymes, low platelet count)syndrome. It is a serious condition that usually indicates that the baby must be born immediately. Usually, the baby's platelet levels will be normal, and the mother's platelets will also become normal a few weeks after birth.
3) Immune Thrombocytopenia (ITP) - It is an autoimmune condition stimulated due to platelet destruction in the spleen. It occurs before pregnancy when the immune system attacks the body's platelets. It normally occurs after a viral infection that happens during childhood. Often, this condition is diagnosed before becoming pregnant, but in some cases, it is noticed in early pregnancy blood tests. Immune thrombocytopenia is usually treated with steroids. If the mother develops ITP, there is an increased chance of the baby having low platelets. The following are several symptoms that are linked to immune thrombocytopenia:
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Rash that appears on the lower legs. This happens due to bleeding under the skin.
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Blood in urine or stools.
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Bleeding from nose and gums.
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Bruising easily.
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Long time to stop bleeding.
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Heavy bleeding during periods.
4) Fatty Liver - Acute fatty liver of pregnancy (AFLP) is a rare condition occurring during pregnancy. But it can cause serious complications. The platelet count may be reduced below 20,000 per microliter of blood in women with this condition.
5) Other Causes - Nutritional deficiencies like vitamin B12 and folate, autoimmune diseases, kidney infections, excessive alcohol intake, thrombotic thrombocytopenic purpura, certain medications such as blood thinners, viral infections such as HIV and CMV, and bone marrow diseases may be some of the other causes of thrombocytopenia in pregnancy.
What Are the Symptoms of Thrombocytopenia During Pregnancy?
Thrombocytopenia does not show any symptoms in most cases. However, some women may show common signs of thrombocytopenia that include:
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Presence of blood in the stool or urine.
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Fatigue.
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Frequent bleeding from nose and gum.
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The appearance of tiny red round spots called petechiae is caused due to bleeding under the skin.
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Brown or red bruises (purpura).
What Is the Risk of Thrombocytopenia During Pregnancy?
The presence of low platelets during pregnancy can be a great concern, as it can cause increased bleeding during delivery. This is a concern when a c-section is required, which can cause blood loss more than vaginal birth. This is because the uterus has the largest supply of blood when compared with the other organs in the body. So during the surgery, the blood vessels are cut to open the uterus wall. In women with low platelets, there is the risk of excessive blood loss and requires a blood transfusion.
Additionally, if an epidural is required, the anesthetist should be very cautious about placing the epidural needle because an accidental puncture in the epidural space can cause the collection of blood in one place (a spinal epidural hematoma). It is a very rare condition, but it can cause permanent paralysis and injury to the spine.
What Is the Effect of Thrombocytopenia on the Baby?
If thrombocytopenia is mild, it causes no complications for the mother and fetus. But, severe thrombocytopenia and underlying medical conditions can cause severe complications for the baby and the mother. Also, women having low platelet count in the first trimester of pregnancy can sometimes lead to miscarriage. There is no research proving that thrombocytopenia alone can cause any complications or birth defects in babies. If women have mild to moderate thrombopenia during pregnancy, they should watch their symptoms and have regular checkups to avoid complications.
What Is the Treatment for Thrombocytopenia During Pregnancy?
Mild thrombocytopenia occurs commonly during pregnancy and requires no treatment. But depending on the severity and cause of thrombocytopenia, women may require treatment. Multidisciplinary care, along with a hematologist, is needed in pregnant women requiring treatment. The treatment options for thrombocytopenia in pregnancy may include the following:
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Oral Prednisone - This is the first-line treatment for thrombocytopenia in pregnant women. It is considered safe during pregnancy. However, few studies have shown its link with certain side effects like gestational diabetes.
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Intravenous Immunoglobulins and Corticosteroids - Studies have shown that this therapy is safe in pregnant women with ITP.
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Plasma Exchange - This therapy can be used in severe AFLP (acute fatty liver of pregnancy) and HELLP syndrome cases.
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Blood or Platelet Transfusions - Transfusion of platelets is indicated in case of emergency C- section and when the platelet count drastically falls below 50,000 per microliter.
Conclusion
Thrombocytopenia occurs commonly during pregnancy, especially in the third trimester of pregnancy, and does not require any treatment. It causes no complications to the mother and baby if it is mild to moderate. If thrombocytopenia is severe and accompanied by other medical conditions, special care, and attention should be given to avoid complications.
