摘要
The purpose of this study was to determine whether stan-dard therapeutic doses of dalteparin maintain peak thera-peutic levels of anticoagulation du ring pregnancy.This was a prospective trial in which 13pregn ancies that required therapeutic anticoagulation were t reated with dalteparin100U /kg every 12hours;peak and trou gh(predose)low molecular weight heparin(anti -Xa activity)levels were monitored every 2weeks.Dosage adju stments were made to maintainpeak anti -Xa activity betw een0.5and1.0IU/ml.Bone density and bone turnover markers were measured.A total of 250peak and trough low -mole cular -weight heparin(LMWH)levels were obtained.Eighty -five p er-cent of pregnancies(11/13)required an upward dosage adjustment.Trough levels were in th e therapeutic range only 9%of the time,despite the maint enance of thera-peutic peak levels.Bone resorption markers and density were unchanged in singleton pregnan cies.Dalteparin dos-ing,based on weight alone,every 12h ours is inadequateto maintain most pregnantwomen in th e therapeutic range throughout pregnancy as measured by anti -Xa activity.Trough levels are rarely in the thera peutic range,despite maintenance of therapeutic peak levels.These notable changes in low molecular weight heparin peak may explain reported failures in pregnancy.
The purpose of this study was to determine whether stan-dard therapeutic doses of dalteparin maintain peak thera-peutic levels of anticoagulation du ring pregnancy.This was a prospective trial in which 13pregn ancies that required therapeutic anticoagulation were t reated with dalteparin100U /kg every 12hours;peak and trou gh(predose)low molecular weight heparin(anti -Xa activity)levels were monitored every 2weeks.Dosage adju stments were made to maintainpeak anti -Xa activity betw een0.5and1.0IU/ml.Bone density and bone turnover markers were measured.A total of 250peak and trough low -mole cular -weight heparin(LMWH)levels were obtained.Eighty -five p er-cent of pregnancies(11/13)required an upward dosage adjustment.Trough levels were in th e therapeutic range only 9%of the time,despite the maint enance of thera-peutic peak levels.Bone resorption markers and density were unchanged in singleton pregnan cies.Dalteparin dos-ing,based on weight alone,every 12h ours is inadequateto maintain most pregnantwomen in th e therapeutic range throughout pregnancy as measured by anti -Xa activity.Trough levels are rarely in the thera peutic range,despite maintenance of therapeutic peak levels.These notable changes in low molecular weight heparin peak may explain reported failures in pregnancy.
