title: βhCG monitoring after single-dose methotrexate treatment of tubal ectopic pregnancy: is the Day 4 βhCG necessary? A retrospective cohort study.
abstract: BACKGROUND
  In ectopic pregnancy (EP) management, failure of βhCG to fall more than 15% between Days 4 and 7 after methotrexate administration indicates the need for a second dose. Regimens preferring a 25% fall in βhCG between methotrexate administration and Day 7 have been proposed.
  
  
  OBJECTIVE
  Our study analysed these and other regimens' performance in predicting treatment success. Secondarily, we investigated how each regimen guided the prescription of additional methotrexate doses.
  
  
  METHODS
  Medical files of 88 women with ultrasound confirmed tubal EP and pretreatment βhCG <6000 IU/L, unsuitable for expectant management, were retrospectively analysed. The βhCG monitoring regimens studied were (i) 15% fall Day 4-7, (ii) 25% fall Day 0/1-7, (iii) any fall Day 0/1-7, (iv) any fall Day 0/1-4 and (v) 20% fall Day 0/1-4. Treatment success was defined if the EP resolved without surgical intervention. Statistical analysis was performed using McNemar's test.
  
  
  RESULTS
  Overall, treatment success with methotrexate was 92% (n = 81/88). Predicting success of methotrexate (PPV 98-100%) and detecting those needing surgery (specificity 86-100%) were equivalent across all monitoring regimens. However, the 25% Day 0/1-7 fall (and the Day 0/1-4 regimens) over-selected women for a second dose of methotrexate (P < 0.05).
  
  
  CONCLUSIONS
  The performance of each regimen is equivalent to the traditional 15% fall Day 4-7 regimen in predicting treatment success. However, a regimen aiming for a 25% fall in βhCG Day 0/1-7 over-selects patients for a second methotrexate dose. In comparison, any drop in βhCG Day 0/1-7 does not over-select women and eliminates Day 4 testing.
authors.affiliation: Department of Obstetrics and Gynaecology, Westmead Hospital, Westmead, New South Wales, Australia.
authors.forename: Monique
authors.initials: M
authors.lastname: Atkinson
authors.forename: Sarika
authors.initials: S
authors.lastname: Gupta
authors.forename: Therese
authors.initials: T
authors.lastname: Mcgee
mesh_terms: D000020:Abortifacient Agents, Nonsteroidal / Q000008:administration & dosage*; D000328:Adult; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood*; D005260:Female; D006801:Humans; D008727:Methotrexate / Q000008:administration & dosage*; D011247:Pregnancy; D011274:Pregnancy, Tubal / Q000097:blood / Q000188:drug therapy*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: D000020:Abortifacient Agents, Nonsteroidal; D018997:Chorionic Gonadotropin, beta Subunit, Human; D008727:Methotrexate
keywords: ectopic pregnancy; human chorionic gonadotrophin; methotrexate; predictive value of tests; treatment failure