What Are the Causes of Neonatal Thrombocytopenia?

Neonatal thrombocytopenia, low blood platelet count, is a common condition among sick or premature infants, particularly in the neonatal intensive care unit of hospitals. This blood disorder is characterized as having a platelet count of under 150,000/uL (microliter), but in newborns any count of under 100,000/uL is definitely abnormal at any gestational age. Numbers between 100,000/uL and 150,000/uL are questionable and require follow-up.

Thrombocytopenia is an indication of some other health issue, and is seen in 20 to 50 percent of infants admitted to neonatal intensive care units, according to the Pediatric Oncall website.

Identification

• Of the 4 million births each year in the United States, about 36,000 have congenital thrombocytopenia and of those 11,000 will develop serious cases, according to the Pediatric Oncall website.

  Thrombocytopenia can be caused by a variety of factors including immune-system issues, infection, drug reactions, congenital and genetic disorders, miscellaneous illnesses and idiopathic or unknown causes.

  Miscellaneous illnesses include conditions such as intrauterine growth retardation, pregnancy-induced hypertension, perinatal asphyxia and narcotizing enterocolitis, inflammation of the intestines.

Time Frame

• Basically, neonatal thrombocytopenia occurs in three different time frames: fetal, early onset or first 72 hours of life, or late onset or after the first 72 hours of life, according to the Metro Health website.

  A pattern of thrombocytopenia occurring by day 4 and resolving by day 10 has been observed, according to research findings published in the "Journal of Pediatrics" in 1986. The study, "Frequency and Mechanism of Neonatal Thrombocytopenia," after a year-long study involving 807 infants in neonatal intensive care units found that a significant risk factor for thrombocytopenia is birth asphyxia .

Treatment

• The treatment of thrombocytopenia depends on the cause and the platelet level.

  In the neonatal immune variety, no treatment will be necessary in mild cases. When levels falls below 30,000/uL, treatment with washed maternal platelets is typical. Sometimes intravenous immunoglobulin is used, and in cases of bleeding, steroids may be administered.

  In the case of bacterial infections treatment is typically unnecessary, but should bleeding occur, platelet transfusions may be needed.

  In general, transfusion is recommended for platelet levels under 50,000/uL in preterm or sick infants and under 20,000/u/L in other infants, according to the Metro Health website.

Idiopathic Causes

• However in over 60 percent of cases, the cause of thrombocytopenia is unknown or idiopathic, according to the Pediatric Oncall website.

  Typically, in these cases where the cause is unknown, the platelet levels will be in the range of 50,000 to 100,000 and may stay around that level for several weeks.

  Several conditions, such as pulmonary hypertension, placental insufficiency and prematurity tend to be present with idiopathic cases of thrombocytopenia.

Considerations

• Something that should be considered in every initial diagnosis of thrombocytopenia is that improper blood collection procedures or inadequate anticoagulants are the most common causes of low platelet count. As such, it is recommended that whenever thrombocytopenia is diagnosed, it should be confirmed with a peripheral blood smear.