What is the diagnosis for a 30-year-old woman, gravida (number of times pregnant) 1, para (number of viable births) 0, at 29 weeks gestation, presenting with increasing fatigue, shortness of breath on exertion, and bilateral leg swelling, with a hemoglobin level of 11.2 g/dL, thrombocytopenia (low platelet count), and 2+ pitting edema?

Differential Diagnosis

• Single most likely diagnosis
  • Gestational thrombocytopenia: This condition is characterized by a mild decrease in platelet count, typically below 150,000/mm^3, during the second or third trimester of pregnancy. The patient's platelet count has decreased from 240,000/mm^3 to 118,000/mm^3, which is consistent with this diagnosis. The symptoms of fatigue, shortness of breath, and bilateral leg swelling are also common in pregnancy due to increased blood volume and venous pressure.
• Other Likely diagnoses
  • Iron deficiency anemia: The patient's hemoglobin level has decreased from 11.8 g/dL to 11.2 g/dL, which may indicate iron deficiency anemia. This condition is common in pregnancy due to increased iron demands.
  • Pregnancy-induced hypertension (PIH): Although the patient's blood pressure is currently normal, PIH can cause symptoms such as fatigue, shortness of breath, and leg swelling. However, the diagnosis of PIH typically requires a blood pressure of 140/90 mmHg or higher.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed)
  • Preeclampsia with severe features: This condition can cause thrombocytopenia, and the patient's symptoms of fatigue, shortness of breath, and leg swelling could be indicative of preeclampsia. Although the patient's blood pressure is currently normal, preeclampsia can progress rapidly and cause severe complications if left untreated.
  • Hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome: This condition is a variant of preeclampsia and can cause thrombocytopenia, fatigue, and shortness of breath. HELLP syndrome can be life-threatening if not promptly diagnosed and treated.
• Rare diagnoses
  • Thrombotic thrombocytopenic purpura (TTP): This rare condition is characterized by thrombocytopenia, microangiopathic hemolytic anemia, and renal failure. Although the patient's symptoms are not typical of TTP, it is a rare but potentially life-threatening condition that should be considered in the differential diagnosis.
  • Immune thrombocytopenic purpura (ITP): This condition is characterized by isolated thrombocytopenia, and the patient's platelet count has decreased significantly. However, ITP is less common in pregnancy, and the patient's symptoms are not typical of this condition.