MKSAP: 35-year-old woman with new-onset thrombocytopenia

A 35-year-old woman is evaluated for new-onset thrombocytopenia. She is gravida 1 at 36 weeks’ gestation. Her pregnancy has been otherwise uncomplicated. She takes only a prenatal vitamin.

On physical examination, temperature is normal, blood pressure is 110/65 mm Hg, pulse rate is 110/min, and respiration rate is 22/min. There are no ecchymoses or petechiae. Abdominal examination discloses no right upper quadrant pain. She has a gravid uterus. Neurologic examination is normal, and there is no peripheral edema.

Laboratory studies:

Hematocrit 33%
Hemoglobin 11.0 g/dL (110 g/L)
Leukocyte count 9500/µL (9.5 × 109/L)
Mean corpuscular volume 85 fL
Platelet count 95,000/µL (95 × 109/L)
Fibrinogen 350 mg/dL (3.5 g/dL)
Alanine aminotransferase Normal
Aspartate aminotransferase Normal
Urinalysis Normal

No schistocytes or platelet clumping is seen on the peripheral blood smear.

Which of the following is the most appropriate management?

A: Corticosteroids
B: Emergent delivery of fetus
C: Intravenous immune globulin
D: Plasma exchange
E: Repeat complete blood count in 1 to 2 weeks

MKSAP Answer and Critique

The correct answer is E: Repeat complete blood count in 1 to 2 weeks.

Repeating the complete blood count in 1 to 2 weeks is appropriate. This patient has new-onset asymptomatic thrombocytopenia developing in the last trimester of pregnancy that is characterized by a platelet count higher than 50,000/µL (50 × 109/L), which suggests gestational thrombocytopenia. Gestational thrombocytopenia is the most common cause of pregnancy-associated thrombocytopenia. The cause of gestational thrombocytopenia is unknown, although it is not believed to have an immune basis. Gestational thrombocytopenia occurs in approximately 5% of pregnancies. Conversely, thrombocytopenia developing in the first two trimesters of pregnancy that is characterized by platelet counts lower than 50,000/µL (50 × 109/L) suggests immune (also termed “idiopathic”) thrombocytopenic purpura.

Several studies have confirmed that maternal and fetal outcomes are excellent in patients with platelet counts higher than 50,000/µL (50 × 109/L), and no resulting maternal or fetal complications, such as fetal thrombocytopenia, should occur. Consequently, no therapeutic interventions, including intravenous immune globulin, plasma exchange, or corticosteroids, are required in this patient, and the fetus does not need to be emergently delivered.

Key Point

  • Gestational (mild) thrombocytopenia is the most common cause of pregnancy-associated thrombocytopenia and has a benign course.

This content is excerpted from MKSAP 16 with permission from the American College of Physicians (ACP). Use is restricted in the same manner as that defined in the MKSAP 16 Digital license agreement. This material should never be used as a substitute for clinical judgment and does not represent an official position of ACP. All content is licensed to on an “AS IS” basis without any warranty of any nature. The publisher, ACP, shall not be liable for any damage or loss of any kind arising out of or resulting from use of content, regardless of whether such liability is based in tort, contract or otherwise.

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