Pregnancy in patients with idiopathic thrombocytopenic purpura: assessing the risks for the infant at delivery.

The objective of this review is to estimate the risk of severe thrombocytopenia at birth and minor or major morbidity for the infant of a pregnancy complicated by immune thrombocytopenic purpura. English language publications on immune thrombocytopenic purpura in pregnancy from January 1980 to December 1990 were used. Manuscripts considered for infant risk assessment fulfilled the following criteria: 10 or more entrants, reported fetal platelet samples (cordocentesis, scalp sampling or cord sample at birth), and provided all infant platelet data. All other data not fulfilling these criteria are reported. The main results were 11 manuscripts reporting 288 live-born infants fulfilled the criteria enabling assessment of infant risk. There were no deaths or intracranial hemorrhages in these studies and secondary morbidity occurred in 3.5 per cent (95 per cent CI 1.4-5.6 per cent). An infant platelet count of less than 50 x 10(9) per liter was reported in 10.1 per cent (95 per cent CI 6.6-13.6 per cent) and an infant platelet count of less than 20 x 10(9) per liter occurred in 4.2 per cent (95 per cent CI 1.9-6.5 per cent). Neither cordocentesis, scalp sample, nor umbilical cord sampling at birth altered the outcome of these infants and minor morbidity occurred equally in vaginal and cesarean births. Smaller case reports (less than 10 entrants) significantly over-estimated the prevalence of severe infant thrombocytopenia and secondary morbidity. All deaths and intracranial hemorrhages were reported in manuscripts which did not specify the timing of infant platelet count determination; thus the relationship of these events to the event of birthing was unclear.(ABSTRACT TRUNCATED AT 250 WORDS)