title: Ectopic pregnancy risk with assisted reproductive technology procedures.
abstract: OBJECTIVE
  To assess the ectopic pregnancy risk among women who conceived with assisted reproductive technology (ART) procedures.
  
  
  METHODS
  The ectopic rate for ART pregnancies was calculated from population-based data of pregnancies conceived with ART in U.S. clinics in 1999-2001. Variation in ectopic risk by patient and ART treatment factors was assessed by using bivariate analyses and multivariable logistic regression.
  
  
  RESULTS
  Of 94,118 ART pregnancies, 2,009 (2.1%) were ectopic. Variation was observed by procedure type. In comparison with the ectopic rate (2.2%) among pregnancies conceived with in vitro fertilization and transcervical transfer of freshly fertilized embryos from the patient's oocytes (fresh, nondonor IVF-ET), the ectopic rate was significantly increased when zygote intrafallopian transfer (ZIFT) was used (3.6%) and significantly decreased when donor oocytes were used (1.4%) or when a gestational surrogate carried the pregnancy (0.9%). Among fresh nondonor IVF-ET procedures, the risk for ectopic pregnancy was increased among women with tubal factor infertility (odds ratio [OR] 2.0, 95% confidence interval [CI] 1.7-2.4; referent group = ART for male factor), endometriosis (OR 1.3, 95% CI 1.0-1.6), and other nontubal female factors of infertility (OR 1.4, 95% CI 1.2-1.6) and decreased among women with a previous live birth (OR 0.6, 95% CI 0.5-0.7). Transfer of embryos with an indication of high implantation potential was associated with a decreased ectopic risk when 2 or fewer embryos were transferred (OR 0.7, 95% CI 0.5-0.9), but not when 3 or more embryos were transferred.
  
  
  CONCLUSIONS
  Ectopic risk among ART pregnancies varied according to ART procedure type, reproductive health characteristics of the woman carrying the pregnancy, and estimated embryo implantation potential.
  
  
  METHODS
  II-2.
authors.affiliation: Division of Reproductive Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
authors.forename: Heather B
authors.initials: HB
authors.lastname: Clayton
authors.forename: Laura A
authors.initials: LA
authors.lastname: Schieve
authors.forename: Herbert B
authors.initials: HB
authors.lastname: Peterson
authors.forename: Denise J
authors.initials: DJ
authors.lastname: Jamieson
authors.forename: Meredith A
authors.initials: MA
authors.lastname: Reynolds
authors.forename: Victoria C
authors.initials: VC
authors.lastname: Wright
mesh_terms: D005260:Female; D006801:Humans; D016015:Logistic Models; D011247:Pregnancy; D011271:Pregnancy, Ectopic / Q000453:epidemiology / Q000209:etiology*; D027724:Reproductive Techniques, Assisted / Q000009:adverse effects*; D012307:Risk Factors; D014481:United States / Q000453:epidemiology