What is the recommended management for a pregnant patient with chronic Immune Thrombocytopenic Purpura (ITP) and thrombocytopenia at 9 months of gestation?

Management of Chronic ITP at 9 Months of Pregnancy with Platelet Count 35,000/µL

This patient requires treatment with either corticosteroids or intravenous immunoglobulin (IVIg) to achieve a platelet count of at least 50,000/µL for safe delivery, with a target of ≥75,000/µL if neuraxial anesthesia is desired. 1

Treatment Indication and Target Platelet Counts

• Treatment is clearly indicated at this gestational age with a platelet count of 35,000/µL, as delivery is imminent and safe hemostasis is required. 1

• Target platelet count for cesarean section: ≥50,000/µL (considered adequate by hematologists for surgical hemostasis). 1

• Target platelet count for epidural/spinal anesthesia: ≥75,000/µL (recommended by obstetric anesthetists to minimize risk of epidural hematoma). 1

• Throughout the first two trimesters, treatment thresholds are lower (20-30,000/µL), but at 9 months gestation, the approach shifts to ensuring adequate platelet counts for delivery. 1

First-Line Treatment Options

Corticosteroids

• Prednisone 10-20 mg/day is the initial dose, adjusted to achieve a hemostatically safe platelet count. 1

• Do not aggressively taper in the final weeks before delivery, as thrombocytopenia commonly worsens during this period. 1

• Important caveats: Corticosteroids can exacerbate hypertension, hyperglycemia, and cause excessive weight gain—particularly problematic at term. 1

• Prednisone is metabolized by placental 11-beta-hydroxylase, providing some fetal protection, though high doses may still affect the fetus. 1

Intravenous Immunoglobulin (IVIg)

• IVIg 1 g/kg as a single dose should be used when corticosteroids are ineffective, contraindicated, or when a more rapid platelet increase is required for imminent delivery. 1

• IVIg can be repeated as needed to maintain safe platelet counts for delivery. 1

• Response rates in pregnant women are similar to non-pregnant patients. 1

• Advantage at 9 months: IVIg provides faster platelet response than corticosteroids, which is critical when delivery may occur within days. 1

Combination Therapy

• Combining corticosteroids with IVIg is appropriate when single-agent therapy fails to achieve target platelet counts as delivery approaches. 1

• High-dose methylprednisolone (HDMP 1000 mg) combined with IVIg has been suggested for refractory cases in late pregnancy. 1

Alternative Treatment (If Applicable)

IV Anti-D Immunoglobulin

• IV anti-D 50-75 µg/kg can be used if the patient is Rh(D)-positive and non-splenectomized. 1

• Important limitation: Often requires augmentation with corticosteroids or IVIg to achieve the target platelet count of 50,000/µL for delivery. 1

• Monitor the neonate for jaundice, anemia, and positive direct antiglobulin test after delivery. 1

Treatments to AVOID During Pregnancy

The following agents should NOT be used due to teratogenicity concerns: 1

• Rituximab
• Thrombopoietin receptor agonists (though one case report 2 describes eltrombopag use, this remains experimental with insufficient safety data)
• Danazol
• Vinca alkaloids
• Most immunosuppressive drugs (except azathioprine, which has too slow an onset for this clinical scenario)

Delivery Management

Mode of Delivery

• Delivery mode should be determined by obstetric indications only, not by maternal ITP or platelet count. 1

• There is no evidence that cesarean section is safer for the fetus with potential thrombocytopenia compared to uncomplicated vaginal delivery. 1

• The risk of severe neonatal thrombocytopenia is 8.9-14.7%, but intracranial hemorrhage occurs in only 0-1.5% of thrombocytopenic neonates, with most hemorrhagic events occurring 24-48 hours postpartum at the platelet nadir. 1

Anesthesia Considerations

• Coordinate closely with obstetric anesthesia regarding platelet count targets for neuraxial anesthesia. 1

• If platelet count remains <75,000/µL despite treatment, general anesthesia may be required for cesarean section. 1

Monitoring Strategy

• Increase frequency of platelet monitoring as delivery approaches, as platelet counts commonly fall in the third trimester. 1

• Monitor platelet response to treatment every 1-2 days when initiating therapy at term. 1

• After delivery, continue monitoring maternal platelet counts and taper corticosteroids slowly to avoid rapid platelet decline. 1

Neonatal Considerations

• Neonatal platelet count should be checked at birth and monitored for 2-5 days, as the nadir typically occurs 24-48 hours after delivery. 1

• Maternal antiplatelet antibodies can cross the placenta, but severe neonatal thrombocytopenia is uncommon and cannot be reliably predicted. 3, 4, 5

• Fetal scalp sampling during labor is not necessary and not recommended. 6