Pregnancy test: why monitor platelets?

The number of blood platelets is checked regularly throughout the pregnancy during blood tests taken during prenatal examinations. Most of the time, the analysis does not reveal anything serious but, more rarely, it can highlight a disorder requiring treatment.

Platelet count: two major reasons to evaluate it during pregnancy

Your platelet count is assessed regularly during your pregnancy for two main reasons:

  • First, to detect a possible haemorrhagic risk and correct it as soon as possible. Indeed, platelets are necessary for blood clotting. Therefore, when they are really too few, the body has trouble stopping blood loss.
  • Then, because a drop in platelets (thrombocytopenia) is sometimes the first symptom of a more or less severe disorder; rapid care can then eliminate the risk of complications.
  • To note : further examinations (blood pressure, other tests, etc.) may be necessary to determine the exact cause of thrombocytopenia.

Platelet drop: the main causes during pregnancy

  • Ideally, the platelet count should be between 150,000 and 400,000 platelets per mm3 of blood, knowing that the "standards" may vary slightly from one laboratory to another.
  • The vast majority of thrombocytopenia detected during pregnancy (approximately 70 to 75% of cases) are mild and have no known cause. Specifically, we talk about essential thrombocytopenia, especially during the third trimester.
  • Good news: this moderate reduction of platelets usually presents no particular risk, neither for you, nor for your future baby! Childbirth can normally take place vaginally, except for other medical conditions requiring a cesarean section.
  • More rarely, thrombocytopenia more or less important during pregnancy may also be due to iron deficiency, certain infections, high blood pressure or a rhesus incompatibility. Platelet decline may also be simply due to taking certain medications (antiepileptics, for example).

Low platelet count: what treatments during pregnancy?

  • Generally, no treatment is necessary for essential thrombocytopenia. The medical team just monitors its progress, including after pregnancy: a blood test is performed about three months after delivery to check that the platelet count is back to normal.
  • In other cases, different treatments may be considered depending on the cause of platelet decline, usually of a medicinal nature. Your doctor may, for example, prescribe iron supplementation in case of deficiency, or - in case of pregnancy-induced hypertension - prescribe medication for stress, put you at rest and give you dietary recommendations (not too much salt, fat and sugar).
  • More rarely, platelet transfusions may be needed in the most severe forms of thrombocytopenia.