What are the causes of thrombocytopenia during pregnancy?

Pregnancy complicated by idiopathic thrombocytopenia is a clinical syndrome in which platelet destruction is increased due to immune mechanisms, also known as immune thrombocytopenia. It is characterized by shortened platelet lifespan, increased bone marrow megakaryocytes, and accelerated platelet turnover rate. Clinically it is divided into acute and chronic types. This disease does not affect fertility, so there are many cases of pregnancy complicated with thrombocytopenia. So what are the causes of pregnancy complicated with thrombocytopenia?

1. Pregnancy combined with thrombocytopenia is very common, mainly including the following reasons:

1. Pregnancy-related thrombocytopenia: Many scholars at home and abroad believe that pregnancy-related thrombocytopenia is caused by the increase in blood volume after pregnancy, which leads to a relative decrease in platelets rather than increased platelet destruction. The degree of platelet decrease is usually small, the condition is relatively mild, and it can usually recover on its own after delivery;

2. Pregnancy complicated with idiopathic thrombocytopenic purpura: the platelet count is usually severely decreased, hemoglobin and white blood cells are usually normal, and megakaryocytes are significantly increased with maturation disorders. If not actively treated, the harm is likely to be serious.

3. HELLP syndrome: Hemolysis, elevated liver enzymes, and thrombocytopenia syndrome refers to a group of clinical syndromes complicated by hemolysis, elevated liver enzymes, and thrombocytopenia on the basis of hypertensive disorders complicating pregnancy. Since this syndrome is a serious complication of pregnancy and is progressive, only termination of pregnancy can effectively eliminate the cause and improve the prognosis of mother and baby. Once diagnosed, the pregnancy should be terminated within 48 hours, especially when the fetus is in distress, the condition worsens, or DIC is suspected. The delivery should be ended as soon as possible, as delayed delivery will cause adverse consequences.

2. Clinical manifestations

1. Acute

It is common in children, accounting for 90% of immune thrombocytopenia cases, with similar incidence in boys and girls. 84% of cases have a history of respiratory tract infection or other viral infection 1 to 3 weeks before onset, so the incidence is most common in autumn and winter. The onset is acute, with possible fever, chills, sudden onset of widespread and severe skin and mucous membrane purpura, and even large ecchymosis or hematoma. Skin petechiae are mostly systemic, mostly on the lower limbs, and are evenly distributed. Mucosal bleeding is common in the nose and gums, and blood blisters may occur in the mouth. Gastrointestinal and urinary tract bleeding is uncommon, and intracranial hemorrhage is rare but life-threatening.

2. Chronic type

It is common in young women, with the incidence rate in women being 3 to 4 times that in men. The onset is slow or insidious, and the symptoms are mild. Bleeding often occurs repeatedly, and each episode can last from several days to several months. The degree of bleeding is related to the platelet count. If the platelet count is >50×109/L, it is often bleeding after injury. If the platelet count is (10-50)×109/L, there may be varying degrees of spontaneous bleeding. If the platelet count is <10×109/L, there is often severe bleeding. Skin purpura is more common in the distal lower limbs, and may be accompanied by bleeding from the nose, gums, and oral mucosa. Excessive menstruation is sometimes the only symptom in women, and there have been cases of death caused by intracranial hemorrhage. Spontaneous remission is rare in this type.

In short, thrombocytopenia during pregnancy is a common hemorrhagic disease, which is often harmful to mother and fetus. The disease is prone to recurrence, especially during delivery, surgery, and anesthesia, which is prone to severe bleeding, and may affect the outcome of the pregnancy. Therefore, once thrombocytopenia is found, a clear diagnosis should be made as soon as possible, and active treatment should be given to reduce the risk.