Female Reproductive System ORGAN SYSTEMS

Thrombocytopenia in pregnancy

Blood platelet count < 150,000/ìL during pregnancy.

Blood platelet count < 150,000/ìL during pregnancy.

  • #2 M/C hematological abnormality in pregnancyy (after anaemia)


Obstetric conditions:

Common causes
  • Gestational thrombocytopenia (GT) (M/C cause, 65-80%): Benign condition with moderate thrombocytopenia with no bleeding risk to mother or fetus
  • Immune (idiopathic) thrombocytopenic purpura (#2 M/C): Autoimmune disorder characterized by anti-platelet glycoprotein antibodies that stimulate the platelet destruction in spleen
  • Hypertensive disorder in pregnancy (PIH) (#3 M/C):
    • Pre-eclampsia (PEC)
    • Hemolysis, elevated liver enzymes, low platelets (HELLP) syndrome
    • Acute fatty liver of pregnancy (AFLP)
Causes of thrombocytopenia in pregnancy | Myers, B. (2009), Thrombocytopenia in pregnancy. The Obstetrician & Gynaecologist, 11: 177-183. doi:10.1576/toag.
Hypertensive and microangiopathic disorders of pregnancy: usual characteristics | Myers, B. (2009), Thrombocytopenia in pregnancy. The Obstetrician & Gynaecologist, 11: 177-183. doi:10.1576/toag.

Secondary to systemic disorders:

  • TMA not specific to pregnancy:
    • Thrombotic thrombocytopenic purpura (TTP)
    • Atypical hemolytic-uremic syndrome (HUS)
  • Disseminated intravascular coagulation (DIC)
  • Other syndromes:
    • Bone marrow failure syndromes
    • Paroxysmal nocturnal hemoglobinuria (PNH)
    • Drug-induced thrombocytopenia
    • Type IIB von Willebrand disease (VWD)
    • Heparin-induced thrombocytopenia (HIT)
Prevalence of causes of thrombocytopenia based on trimester of presentation and platelet count: The size of each circle represents the relative frequency of all causes of thrombocytopenia during each of the 3 trimesters of pregnancy. All etiologies and all platelet counts are considered together in the first trimester when thrombocytopenia is uncommon. Distribution of etiologies during the second and third trimesters is subdivided by platelet count. All results are estimates based on personal experience and review of the literature. “Other” indicates miscellaneous disorders, including infection, DIC, type IIB von Willebrand disease, immune and nonimmune drug-induced thrombocytopenia, paroxysmal nocturnal hemoglobinuria, bone marrow failure syndromes (aplastic anemia, myelodysplasia, myeloproliferative disorders, leukemia/lymphoma, and marrow infiltrative disorders), among others. | HUS, hemolytic uremic syndrome; PEC, preeclampsia/HELLP; TTP, thrombotic thrombocytopenic purpura. | Cines, D. B., & Levine, L. D. (2017). Thrombocytopenia in pregnancy. Blood, 130(21), 2271–2277.

Clinical features

Gestational thrombocytopenia:

Patients with gestational thrombocytopenia are often healthy, asymptomatic women who are found to have low platelets on lab investigations.
  • Mucocutaneous bleeding
  • Severe coagulopathies: joint bleed or severe bleeding

Physical examination:

  • Hepatomegaly and/or splenomegaly (cirrhosis, lymphoproliferative disorders, etc.)
  • Skeletal deformities (like absent radius, humeral abnormality and sometimes phocomelia seen in thrombocytopenia absent radii syndrome)
  • Skin exam (like petechiae or purpura seen commonly with ITP, or, eczema seen in Wiskott-Aldrich Syndrome)


Gestational thrombocytopenia (GT):

Characterized by:
  1. Asymptomatic, mild thrombocytopenia (>70 000/μL)
  2. No past history of thrombocytopenia
  3. Occurrence during late gestation
  4. Not associated with fetal thrombocytopenia
  5. Resolves spontaneously after delivery


In pregnancy, thrombocytopenia usually does not lead to an increased risk of bleeding. Even in patients with ITP, where thrombocytopenia is often quite severe, the risk of bleeding remains low.

Treatment is initiated for bleeding when the platelet count falls below 20 × 109/L to 30 × 109/L, and for procedures and delivery.The obstetric indication decides the mode of delivery.

General guideline for interventional levels in non‐haemorrhagic cases of ITP in pregnancy | Myers, B. (2009), Thrombocytopenia in pregnancy. The Obstetrician & Gynaecologist, 11: 177-183. doi:10.1576/toag.

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