title: Use of serum progesterone measurements to reduce need for follow-up in women with pregnancies of unknown location.
abstract: OBJECTIVE
  To assess the efficacy of a progesterone-based algorithm for the management of women with pregnancies of unknown location (PULs) and explore the feasibility of developing a single-visit strategy in those with a low risk of requiring medical intervention.
  
  
  METHODS
  All clinically stable women in whom pregnancy could not be identified on ultrasound scan were managed by a pre-defined protocol based on measurement of serum progesterone and beta-human chorionic gonadotropin (beta-hCG). Intervention in the form of surgery or medical treatment with methotrexate was offered to all women with persistent or worsening symptoms and non-declining serum beta-hCG. Decision-tree analysis was used to develop a protocol for the management of women with resolving pregnancies who are at low risk of requiring medical intervention.
  
  
  RESULTS
  1110 women were included in the data analysis: normal intrauterine pregnancy was diagnosed in 248 (22.3%; 95% CI, 19.9-24.8) women. 761 (68.6%; 95% CI, 65.8-71.3) abnormal pregnancies resolved spontaneously on expectant management, while the remaining 101 (9.1%; 95% CI, 7.4-10.8) women with abnormal pregnancies required some form of medical intervention. Intervention rates in patients presenting with initial serum progesterone levels of <or= 20 nmol/L and <or= 10 nmol/L, were 3.9% (95% CI, 2.4-5.4) and 2.1% (95% CI, 0.9-3.3), respectively. In women presenting with progesterone <or= 10 nmol/L and beta-hCG < 450 IU/L, the intervention rate was 1.3% (95% CI, 0.2-2.5).
  
  
  CONCLUSIONS
  Women with PULs with progesterone <or= 10 nmol/L at presentation are at low risk of requiring medical intervention and may not benefit from attending routine follow-up visits.
authors.affiliation: Early Pregnancy and Acute Gynaecology Assessment Unit, King's College Hospital, London, UK.
authors.forename: A
authors.initials: A
authors.lastname: Day
authors.forename: E
authors.initials: E
authors.lastname: Sawyer
authors.forename: D
authors.initials: D
authors.lastname: Mavrelos
authors.forename: A
authors.initials: A
authors.lastname: Tailor
authors.forename: S
authors.initials: S
authors.lastname: Helmy
authors.forename: D
authors.initials: D
authors.lastname: Jurkovic
mesh_terms: D000020:Abortifacient Agents, Nonsteroidal; D000328:Adult; D000465:Algorithms; D015415:Biomarkers / Q000097:blood; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood*; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008727:Methotrexate; D011237:Predictive Value of Tests; D011247:Pregnancy; D011271:Pregnancy, Ectopic / Q000097:blood / Q000175:diagnosis*; D018566:Pregnancy, High-Risk; D011374:Progesterone / Q000097:blood*; D018570:Risk Assessment; D016216:Ultrasonography, Prenatal
chemical_list: D000020:Abortifacient Agents, Nonsteroidal; D015415:Biomarkers; D018997:Chorionic Gonadotropin, beta Subunit, Human; D011374:Progesterone; D008727:Methotrexate