Routine Postnatal Use of the Kleihauer-Betke Test for Anti-D Administration in Rhesus D-Incompatible Pregnancies: A Medical Student Quality Improvement Project

摘要

Research in Rhesus incompatibility has resulted in multiple evidence-based guidelines, including those issued by the Royal College of Obstetricians and Gynaecologists, the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG), the National Health and Medical Research Council (Australia), and the American College of Obstetricians and Gynecologists.These guidelines all advocate use of the postnatal Kleihauer-Betke (KB) test to quantify the extent of fetomaternal hemorrhage (FMH), with subsequent appropriate administration of Anti-D immunoglobulin to match the degree of fetomaternal spillover in all women with Rhesus D (RhD)-incompatible pregnancies to prevent alloimmunization and subsequent hemolytic disease of the newborn.The recommended initial dose of Anti-D varies from region to region because of a paucity of evidence regarding the optimal initial dose. It is 1,500 international units (IU) in the United States and 625 IU in New Zealand, covering up to 30 mL and 9 mL of fetal blood, respectively, with higher doses needed for larger FMH, as determined by the KB test. FMH larger than 30 mL is uncommon but occurs in approximately 0.6% of pregnant women.