title: IVF outcomes in obese donor oocyte recipients: a systematic review and meta-analysis.
abstract: OBJECTIVE
  Does obesity influence the chance of pregnancy after IVF in donor oocyte recipients?
  
  
  CONCLUSIONS
  The chance of pregnancy after IVF is no different in obese donor oocyte recipients versus those in the normal BMI range.
  
  
  BACKGROUND
  Obesity is associated with decreased chances of pregnancy in women undergoing IVF with autologous oocytes. Prior studies have investigated the impact of obesity on IVF outcomes in donor oocyte recipients, with disparate results. This is the first systematic review and meta-analysis to address this topic.
  
  
  METHODS
  A systematic review and meta-analysis of published literature identified in Medline, EMBASE and Scopus through December of 2011 were performed to address the association between BMI and outcomes for donor oocyte recipients. The primary outcome of this study was implantation.
  
  
  METHODS
  Two authors conducted the searches independently, selected the studies and abstracted the data. Studies in English of first donor oocyte cycles with reported recipient BMI were included. Primary data collected from the IVF program at Washington University were also included as one study (n = 123 donor oocyte recipients). Studies limited to frozen embryo transfer were excluded. Data were synthesized using DerSimonian-Laird random effects models for implantation, clinical pregnancy, miscarriage and live birth.
  
  
  RESULTS
  Of 475 screened articles, 7 were reviewed and 5 were included together with primary data from Washington University, giving a total of 4758 women who were included for the assessment of the primary outcome. No associations between obesity (BMI ≥ 30 kg/m(2)) and chance of pregnancy after IVF were noted in women using donor oocytes [risk ratio (RR): 0.98, 95% confidence intervals (CI): 0.83-1.15, I(2): 61.6%]. Additional analyses assessing associations between recipient obesity and embryo implantation (RR: 0.93, 95% CI: 0.80-1.07, I(2): 0%), miscarriage (RR: 1.12, 95% CI: 0.83-1.50, I(2): 0%) and live birth (RR: 0.91, 95% CI: 0.65-1.27, I(2) 47.9%) also failed to show a negative effect.
  
  
  CONCLUSIONS
  Included studies were small and they were performed in a variety of locations and practice settings where stimulation and laboratory protocols may differ, and extremes of BMI may also differ. Furthermore, included studies had different inclusion and exclusion criteria. These factors could not be controlled for in this meta-analysis and statistical heterogeneity was noted for some outcomes.
  
  
  CONCLUSIONS
  These data suggest obesity does not affect IVF outcomes in women using donor oocytes. Oocyte quality rather than endometrial receptivity may be the overriding factor influencing IVF outcomes in obese women using autologous oocytes.
  
  
  BACKGROUND
  E.S.J. and M.G.T receive support from the Women's Reproductive Health Research Program sponsored by the National Institutes of Health (K12 HD063086). The authors do not have any competing interests.
  
  
  BACKGROUND
  N/A.
authors.affiliation: Department of Obstetrics and Gynecology, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
authors.forename: E S
authors.initials: ES
authors.lastname: Jungheim
authors.forename: S B
authors.initials: SB
authors.lastname: Schon
authors.forename: M B
authors.initials: MB
authors.lastname: Schulte
authors.forename: D A
authors.initials: DA
authors.lastname: DeUgarte
authors.forename: S A
authors.initials: SA
authors.lastname: Fowler
authors.forename: M G
authors.initials: MG
authors.lastname: Tuuli
mesh_terms: D000328:Adult; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D009765:Obesity / Q000150:complications / Q000453:epidemiology*; D018587:Oocyte Donation; D011247:Pregnancy; D011256:Pregnancy Outcome; D018873:Pregnancy Rate; D014019:Tissue Donors
keywords: BMI; donor oocyte recipients; female infertility; gamete donation