title: Log-linear human chorionic gonadotropin elimination in cases of retained placenta percreta.
abstract: OBJECTIVE
  To describe the human chorionic gonadotropin (hCG) elimination rate in patients with intentionally retained placenta percreta.
  
  
  METHODS
  Medical records for cases of placenta percreta with intentional retention of the placenta were reviewed. The natural log of the hCG levels were plotted versus time and then the elimination rate equations were derived.
  
  
  RESULTS
  The hCG elimination rate equations were log-linear in three cases individually (R (2) = 0.96-0.99) and in aggregate R (2) = 0.92). The mean half-life of hCG elimination was 146.3 h (6.1 days).
  
  
  CONCLUSIONS
  The elimination of hCG in patients with intentionally retained placenta percreta is consistent with a two-compartment elimination model. The hCG elimination in retained placenta percreta is predictable in a log-linear manner that is similar to other reports of retained abnormally adherent placentae treated with or without methotrexate.
authors.affiliation: Department of Women's and Children's Health, Section of Obstetrics and Gynaecology, University of Otago Dunedin School of Medicine, Private Bag 1921, Dunedin, 9054, New Zealand, usnpanther@yahoo.com.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Stitely
authors.forename: M
authors.initials: M
authors.lastname: Gerard Jackson
authors.forename: William H
authors.initials: WH
authors.lastname: Holls
mesh_terms: D000020:Abortifacient Agents, Nonsteroidal / Q000627:therapeutic use; D000328:Adult; D006063:Chorionic Gonadotropin / Q000378:metabolism*; D005260:Female; D006801:Humans; D016014:Linear Models; D008727:Methotrexate / Q000627:therapeutic use; D010921:Placenta Accreta / Q000188:drug therapy / Q000378:metabolism*; D018457:Placenta, Retained / Q000188:drug therapy / Q000378:metabolism*; D011247:Pregnancy; D012189:Retrospective Studies
chemical_list: D000020:Abortifacient Agents, Nonsteroidal; D006063:Chorionic Gonadotropin; D008727:Methotrexate