title: Accuracy of a semi-quantitative urine pregnancy test compared to serum beta-hCG measurement: a possible screening tool for ongoing pregnancy after medication abortion.
abstract: OBJECTIVE
  Medication abortion protocols commonly rely on ultrasound or serum hCG measurement to confirm completion. In order to explore the use of a urine-based test to screen for ongoing pregnancy, we compared the diagnostic accuracy of a recently developed semi-quantitative urine pregnancy test to serum beta-hCG testing.
  
  
  METHODS
  We evaluated the urine test with 97 women in early pregnancy at a hospital and private clinic in Mexico City. The results of the urine test (hCG level > or <1000 IU/L) were correlated with those of a serum quantitative beta-hCG immunoradiometric assay.
  
  
  RESULTS
  The sensitivity of the urine test to identify individuals with a serum beta-hCG level >1000 IU/L was 88.6% (95% CI 74.6- 95.7%), and its specificity was 71.7% (95% CI 57.4-82.8%).
  
  
  CONCLUSIONS
  The reasonably high sensitivity of this urine test suggests it might be useful as a screening test to detect ongoing pregnancy after medication abortion. Future research should evaluate its utility in clinical follow-up protocols.
authors.affiliation: Ibis Reproductive Health, c/o Department of Obstetrics and Gynecology, San Francisco General Hospital, San Francisco, CA 94110, USA. dgrossman@ibisreproductivehealth.org
authors.forename: Daniel
authors.initials: D
authors.lastname: Grossman
authors.forename: Karla
authors.initials: K
authors.lastname: Berdichevsky
authors.forename: Fernando
authors.initials: F
authors.lastname: Larrea
authors.forename: Jorge
authors.initials: J
authors.lastname: Beltran
mesh_terms: D000028:Abortion, Induced; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood* / Q000652:urine*; D005260:Female; D006801:Humans; D011247:Pregnancy; D011258:Pregnancy Tests / Q000592:standards*; D011446:Prospective Studies; D017211:Treatment Failure
chemical_list: D018997:Chorionic Gonadotropin, beta Subunit, Human