title: Evaluation of the prognosis of in vitro fertilization pregnancies with initially low serum human chorionic gonadotropin levels.
abstract: OBJECTIVE
  The objective of this study was to investigate the prognostic significance of initially low serum early human chorionic gonadotropin levels in in vitro fertilization pregnancies that progress to an intrauterine gestational sac.
  
  
  METHODS
  This retrospective cohort study compared 65 in vitro fertilization pregnancies with an initial human chorionic gonadotropin value at 4 weeks of < or =20 mIU/mL with 130 pregnancies with human chorionic gonadotropin values >20 mIU/mL. All pregnancies had a singleton intrauterine sac at 6 weeks' gestational age. Spontaneous abortion rates and pregnancy complications were compared.
  
  
  RESULTS
  Women with a low initial serum human chorionic gonadotropin level showed a statistically significant increase in first-trimester pregnancy loss (36.5% vs 9.2%; odds ratio, 5.7; 95%; confidence interval, 2.6, 12.4; P <.0001). Once pregnancies progressed to 13 weeks, there were no significant differences.
  
  
  CONCLUSIONS
  In vitro fertilization pregnancies with a low initial human chorionic gonadotropin value, despite progressing to a gestational sac, are at an increased risk of spontaneous abortion.
authors.affiliation: Department of Obstetrics and Gynecology, Women and Infants' Hospital, Brown University School of Medicine, Providence, RI 02905, USA. Gary_Frishman@Brown.edu
authors.forename: G N
authors.initials: GN
authors.lastname: Frishman
authors.forename: R J
authors.initials: RJ
authors.lastname: Hackett
authors.forename: M
authors.initials: M
authors.lastname: McGrath
authors.forename: W P
authors.initials: WP
authors.lastname: Metheny
mesh_terms: D000022:Abortion, Spontaneous / Q000097:blood / Q000453:epidemiology; D006063:Chorionic Gonadotropin / Q000097:blood*; D015331:Cohort Studies; D005260:Female; D005307:Fertilization in Vitro; D005865:Gestational Age; D006801:Humans; D016017:Odds Ratio; D011247:Pregnancy; D011256:Pregnancy Outcome; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D006063:Chorionic Gonadotropin