Thrombocytopenia in Pregnancy

Top three diagnoses:

1) Gestational thrombocytopenia (70-80%) 2) ITP (1-4%) 3) preeclampsia with HELLP

What are the platelet targets in pregnancy?

• ITP: Vaginal delivery > 30, CS > 50, neuraxial anesthesia > 80
• HELLP/Pre-eclampsia: All >20, CS > 50, actively hemorrhaging or rapidly progressing coagulopathy --> transfuse all

Consider the following workup:

• CBC, retics, smear, liver function, HIV/HBC/HCV, UA/urine protein to creatinine ration
• TSH, ANA, APLA, H pylori, INR/PTT, DAT

Gestational Thrombocytopenia

• most common cause of maternal thrombocytopenia
• typically causes drop in T3 (or newly diagnosed)
• typically the platelets > 70 or more commonly > 100
• this is a diagnosis of exclusion, do your full workup
• no treatment required, typically resolves <6 weeks postpartum

ITP in Pregnancy

• pre-existing thrombocytopenia
• treat when Plt < 30, clinically bleeding, or < 50 near delivery
• Rx: prednisone or IVIG, avoid dexamethasone as this crosses the placenta
• consult pediatrics to rule out neonatal thrombocytopenia (10% of cases)

References

1. 2021 IMR slides (obstetric medicine)