Risk of thrombocytopenia in the infants of mothers with idiopathic thrombocytopenia.

Twenty-nine of 27,662 pregnant women had autoimmune thrombocytopenia at the time of delivery at King Khalid University Hospital over 6 years starting June 1986. Twenty-six had idiopathic thrombocytopenic purpura (ITP), gave birth to 33 infants, of which 22 were by spontaneous vaginal delivery, eight by lower segment cesarean section, and two by forceps. Fourteen (44%) of the 32 living infants had platelets less than 150 x 10(9)/L and four (12.