Table 1. The differential diagnosis of gestational versus autoimmun thrombocytopenia.

Criteria	Gestational thrombocytopenia	Autoimmune thrombocytopenia
% of thrombocytopenia in pregnancy	ca. 75%	ca. 3%
Usual time of onset during pregnancy	Late 2nd to 3rd trimester	1st to early 2nd trimester
Clinical course during pregnancy	Asymptomatic	Elevated rate of spontaneous bleeding if the platelet count is below 20 G/L
History	No prior history of bleeding	Bleeding tendency that manifested itself before pregnancy (e.g., petechiae)
Platelet count indicating diagnosis	≥ 100 G/L	< 100 g/l
Fetal thrombocytopenia	None	Possible*1
Course of platelet count after birth	Normalization within 2 weeks	Rise possible
Treatment	None	Initially: prednisone or prednisolone, 20–30 mg/day*2

^*115–50% < 100 G/L, 10% < 50 G/L

^*2in case of bleeding and/or a platelet count < 20–30 G/L in the 1^st or 2^nd trimester or < 50 G/L in the 3^rd trimester (modified from [4, 16])