What is Platelet Count?

The platelet count test measures the number of platelets in a given blood sample. As a single test, it can tell little about overall health and even less about the particular condition causing the abnormal platelet count. However, when paired with other blood tests measuring complimentary platelet information, one or more possible conditions/causes can be revealed.

In normal pregnancies, the platelet count  decreases from the beginning to the end of the pregnancy, from an average of 260K to about 220K per cubic millimeter. According to a NEJM study, if the platelet count is less than 100,000 per cubic millimeter, then a cause other than pregnancy should be considered. 

Normal Platelet Value Range

  • Negative Pregnancy Adult: 165 to 415X103/mm3X103/µl or 165 to 415X109/L
  • Pregnancy Trimester One: 174 to 391X103/mm3X103/µl or 174 to 391X109/L
  • Pregnancy Trimester Two: 155 to 409X103/mm3X103/µl or 155 to 409X109/L
  • Pregnancy Trimester Three: 146 to 429X103/mm3X103/µl or 146 to 429X109/L

Lower than normal platelet counts can be associated with preeclampsia, hyperthyroidism, HIV and lupus.

High platelet counts could be caused by inflammation, abnormal spleen function or certain forms of leukemia.

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