Maternal Anticonvulsant Therapy and Neonatal Blood Coagulation

Abstract

Hematology-Oncology| June 01 2000 Maternal Anticonvulsant Therapy and Neonatal Blood Coagulation AAP Grand Rounds (2000) 3 (6): 62–63. https://doi.org/10.1542/gr.3-6-62-a Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation Maternal Anticonvulsant Therapy and Neonatal Blood Coagulation. AAP Grand Rounds June 2000; 3 (6): 62–63. https://doi.org/10.1542/gr.3-6-62-a Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search toolbar search search input Search input auto suggest filter your search All PublicationsAll JournalsAAP Grand RoundsPediatricsHospital PediatricsPediatrics In ReviewNeoReviewsAAP NewsAll AAP Sites Search Advanced Search Topics: anticonvulsants, blood coagulation, newborn Source: Hey E. Effect of maternal anticonvulsant treatment on neonatal blood coagulation. Arch Dis Child. 1999;81:F208–210. This prospective and longitudinal study was designed to investigate the impact of maternal anticonvulsant use on the blood coagulation of the newborn. The study was prompted by a report in 1970 describing the high incidence of prothrombin deficiency among infants born to mothers taking anticonvulsant treatment.1 During the 15 years of this study at Newcastle upon Tyne, cord blood prothrombin times were measured in 137 consecutive term newborns of mothers who were on chronic treatment with phenobarbitone, phenytoin, and/or carbamazepine. The anticonvulsant levels were measured in 131 mothers at delivery. A second umbilical venous sample was obtained in 83 of the newborns after administration of 1mg of intravenous vitamin K. Control values consisted of cord blood prothrombin times in 50 term newborns during the first and last year of the study whose mothers had not received any anticonvulsant treatment. The mean and standard deviation of PT values in the 2 groups of control neonates were almost identical despite a change in the thromboplastin used as reagent during the study period. The mean prothrombin time for the 105 babies born to mothers with therapeutic concentration of anticonvulsant was higher than in the control infants, yet only 14 babies (13%) had a prothrombin time above the 95% reference range for control babies. None of the 105 babies developed bleeding, even after intramuscular injection of vitamin K, and the PT abnormality was corrected by at least 25% within a few hours of vitamin K administration. The author concludes that a small population of babies born to mothers on therapeutic blood concentrations of the above mentioned anticonvulsants will show an exaggerated prolongation of prothrombin time, but symptomatic deficiency in the form of a classic hemorrhagic disease of the newborn is rare. Although some babies born to mothers with therapeutic blood concentrations of phenobarbitone, phenytoin, and/or carbamazepine will have prolonged PTs for their age, the infant’s risk of spontaneous bleeding apparently is not increased. The author suggests that case reports of bleeding in babies born to mothers taking phenytoin or a barbiturate occurred secondary to trauma. Would administration of vitamin K to pregnant mothers prevent PT prolongation? We know that maternal prophylaxis with vitamin K does not shorten the PT in the preterm infant2 and the issue remains controversial. The author also speculates that a newer anticonvulsant such as valproate may be safer because it does not seem to cause neonatal hypoprothrombinemia. There is some evidence, however, that valproate causes platelet dysfunction by reducing the activity of the arachidonic cascade, which is involved in promoting platelet aggregation and secretion.3 Whether or not intramuscular administration of vitamin K should be abandoned in favor of repeated oral doses of vitamin K because of the possibility that high levels of vitamin K after parenteral injection increases the risk of malignancy4 remains to be determined. For the time being, intramuscular injection remains the main... You do not currently have access to this content.