[Percutaneous umbilical blood sampling in pregnant women with thrombocytopenia. Apropos of 35 cases].

OBJECTIVE

To determine the interest of percutaneous umbilical blood sampling in maternal thrombocytopenia.

PATIENTS AND METHOD

We performed a retrospective study of 36 percutaneous umbilical samples in pregnant women with thrombocytopenia. We included patients with a platelet count less than 100,000/mm(3) or a previous diagnosis of idiopathic thrombocytopenic purpura. Patients were divided into two groups. Group A consisted of women whose thrombocytopenia was caused by idiopathic thrombocytopenic purpura. The other patients were included in the group B. Percutaneous umbilical blood samples were performed by direct ultrasound guidance under sterile conditions, after 37 weeks gestation. Cesarean section was indicated if the fetal platelet count was < or =50 000/mm(3), in other cases obstetric indications were followed.

RESULTS

Percutaneous umbilical blood samples were performed at a mean age of 38.5 gestational weeks. Fetal blood sampling was successful in 34 of the 36 cases. There was no fetal complication. In group A, two fetuses had low cord-blood platelet counts (20,000 and 98,000 per cubic millimeter). There was no fetal thrombopenia in group B. Three cesarean sections were performed, in one case because of severe fetal thrombocytopenia and in 2 cases because of an unsuccessful percutaneous umbilical blood sampling (in both, neonatal platelet count was normal). There was no significant complication in infants. There was a significant correlation between fetal and neonatal platelet count.

CONCLUSION

There is no maternal predictive factor for fetal thrombocytopenia. Percutaneous umbilical blood sampling is feasible and has a good diagnostic value. The overall risk of fetal loss is low. But there is no indication of percutaneous umbilical blood sampling in the management of thrombocytopenia in pregnancy because severity of thrombopenia is not directly related to the severity of maternal disease and there are no series large enough to assess the association between delivery method and intracranial hemorrhage in thrombocytopenic infants born of mothers with idiopathic thrombocytopenic purpura. More subjectively than on scientific arguments a percutaneous umbilical blood sampling could be performed for patients with idiopathic thrombocytopenia purpura and a past history of neonatal intracranial hemorrhage. A cesarean section could be done if the platelet count is less than 100 000/mm(3), no intracranial hemorrhage has been described above this level.