title: Increased odds of live birth in fresh in vitro fertilization cycles with shorter ovarian stimulation.
abstract: To investigate the impact of prolonged ovarian stimulation on pregnancy outcomes in IVF cycles with fresh day 3 ET.
  
  
  
  Retrospective cohort study.
  
  
  
  University-affiliated center.
  
  
  
  All patients initiating their first IVF cycle with fresh day 3 ET. Prolonged ovarian stimulation was defined as a duration of more than two standard deviations (95th percentile) for the study cohort (i.e., >13 days).
  
  
  
  None.
  
  
  
  Live birth rate was considered the primary outcome and was compared between patients undergoing ovarian stimulation for ≤13 days and >13 days. Odds ratios (OR) with 95% confidence intervals (CI) for all pregnancy outcomes after day 3 ET were calculated. The OR for live birth was adjusted using logistic regression.
  
  
  
  A total of 6,410 and 339 patients underwent ovarian stimulation for ≤13 days and >13 days, respectively. There were no differences in the demographics or mean number of day 3 embryos transferred between the two groups. Ovarian stimulation ≤13 days was associated with increased odds of clinical pregnancy (OR 2.15, 95% CI 1.19-3.89) and live birth (OR 2.35, 95% CI 1.25-4.43). The increased odds for live birth in the ≤13-day group remained unchanged after logistic regression. Patients with clinical pregnancies in the >13-day group were younger (34.6 ± 4.91 years) compared with those who did not conceive (38.2 ± 4.72 years).
  
  
  
  Our findings suggest that ovarian stimulation ≤13 days is associated with increased odds of clinical pregnancy and live birth. In patients undergoing ovarian stimulation >13 days, younger age is associated with live birth.
authors: The Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine, Weill Cornell Medical College, New York, New York. Electronic address: nip9060@med.cornell.edu.
authors: Nigel
authors: N
authors: Pereira
authors: Department of Obstetrics and Gynecology, Weill Cornell Medical College, New York, New York.
authors: Caroline
authors: C
authors: Friedman
authors: Department of Obstetrics and Gynecology, Weill Cornell Medical College, New York, New York.
authors: Anne P
authors: AP
authors: Hutchinson
authors: The Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine, Weill Cornell Medical College, New York, New York.
authors: Jovana P
authors: JP
authors: Lekovich
authors: The Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine, Weill Cornell Medical College, New York, New York.
authors: Rony T
authors: RT
authors: Elias
authors: The Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine, Weill Cornell Medical College, New York, New York.
authors: Zev
authors: Z
authors: Rosenwaks
mesh_terms: D000328:Adult; D016009:Chi-Square Distribution; D004624:Embryo Transfer; D005260:Female; D005298:Fertility; D005300:Fertility Agents, Female / Q000008:administration & dosage* / Q000009:adverse effects; D005307:Fertilization in Vitro / Q000009:adverse effects; D006801:Humans; D007246:Infertility / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D050498:Live Birth; D016015:Logistic Models; D016017:Odds Ratio; D054315:Oocyte Retrieval; D010060:Ovulation / Q000187:drug effects*; D010062:Ovulation Induction / Q000009:adverse effects / Q000379:methods*; D011247:Pregnancy; D018873:Pregnancy Rate; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome
chemical_list: D005300:Fertility Agents, Female
keywords: In vitro fertilization; pregnancy outcomes; prolonged gonadotropin stimulation; prolonged ovarian stimulation