Idiopathic thrombocytopenic purpura (ITP) frequently complicates pregnancies. The outcome for infants with ITP has been reasonably well studied. However, its impact on their mothers has been less well investigated. We report a ten year retrospective stud; ' of mothers with ITP born at one institution. Eighty-three mothers delivered 112 children in 110 deliveries during the study interval. Thrombocytopenia occurred in most, and fir many women there was a progressive fall in the platelet count during the pregnancy that was gradual and not associated with any trimester. Forty-one of the mothers (36.4%) hac a platelet count of less than 50 x lO'/L, and 13 (11.8%) of the women had a platelet coun; of less than 20 x 109/L during the pregnancy or at time of delivery. Thirty-four women (30.9%) were treated during the pregnancy. Seventeen women (50%) were treated witli IVIG, 12 (35.3%) received IVIG and steroids, 4 (11.8%) received steroids alone and (2.9%) was treated with steroids and anti-D. Platelet counts at the time of delivery wen; available for 104 women (90.1%). Seven (6.7%) women had a platelet count less than 20 x lO'/L, 11 (10.6%) had a platelet count from 20-50 x lO'/L. For the 110 deliveries, 40 women (36.4%) had epidural analgesia. Platelet counts at the time of delivery are available for 37 of these women. One women had an epidural placed with a platelet count less than 50x10'/L, 19(51.4%) with a platelet count from 51 -100 x 10'/L, 7(18.9%) with a platele t count 101-150 x 109/L, and 10 (27%) with a platelet count greater than 150 x lO'/L. No women had a complication from the epidural. Despite the relatively seven: thrombocytopenia in the mothers at the time of delivery, only one patient was documentée to have blood loss of greater than 1 litre. This patient's platelet count was 27 x lO'/L. She received neither platelet nor packed red blood cell (PRBC) transfusions. Five patient:; were transfused with platelets. In all cases, the patient's platelet count was greater than 40 x lO'/L and no excessive bleeding was documented. Two patients received a transfusion o:' PRBC. In both patients, there was no documentation of excessive blood loss. Of the 11; infants in the study, platelet counts at birth were available for 83 (74.1 %). Thrombocytopeniï occurred in 24 infants (28.9%) with 9 (10.8%) infants having platelet counts less than 5C x lO'/L. ITP in pregnant women is a relatively benign event, and even women with verj severe thrombocytopenia can be successfully managed during the pregnancy and will gc on to deliver healthy infants.