title: Live birth after fresh embryo transfer vs elective embryo cryopreservation/frozen embryo transfer in women with polycystic ovary syndrome undergoing IVF (FreFro-PCOS): study protocol for a multicenter, prospective, randomized controlled clinical trial.
abstract: BACKGROUND
  Polycystic ovary syndrome (PCOS) patients are at increased risk of pregnancy complications, which may impair pregnancy outcome. Transfer of fresh embryos after superovulation may lead to abnormal implantation and placentation and further increase risk for pregnancy loss and complications. Some preliminary data suggest that elective embryo cryopreservation followed by frozen-thawed embryo transfer into a hormonally primed endometrium could result in a higher clinical pregnancy rate than that achieved by fresh embryo transfer.
  
  
  METHODS
  This study is a multicenter, prospective, randomized controlled clinical trial (1:1 treatment ratio of fresh vs. elective frozen embryo transfers).. A total of 1,180 infertile PCOS patients undergoing the first cycle of in vitro fertilization (IVF) or intracytoplasmic sperm injection will be enrolled and randomized into two parallel groups. Participants in group A will undergo fresh embryo transfer on day 3 after oocyte retrieval, and participants in group B will undergo elective embryo cryopreservation after oocyte retrieval and frozen-thawed embryo transfer in programmed cycles. The primary outcome is the live birth rate. Our study is powered at 80 to detect an absolute difference of 10 at the significance level of 0.01 based on a two-sided test.
  
  
  CONCLUSIONS
  We hypothesize that elective embryo cryopreservation and frozen-thawed embryo transfer will reduce the incidence of pregnancy complications and increase the live birth rate in PCOS patients who need IVF to achieve pregnancy.
  
  
  BACKGROUND
  ClinicalTrials.gov Identifier: NCT01841528.
authors.forename: Yuhua
authors.initials: Y
authors.lastname: Shi
authors.forename: Daimin
authors.initials: D
authors.lastname: Wei
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Liang
authors.forename: Yun
authors.initials: Y
authors.lastname: Sun
authors.forename: Jiayin
authors.initials: J
authors.lastname: Liu
authors.forename: Yunxia
authors.initials: Y
authors.lastname: Cao
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
authors.forename: Richard S
authors.initials: RS
authors.lastname: Legro
authors.forename: Heping
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Center for Reproductive Medicine, Shandong Provincial Hospital Affiliated to Shandong University, Reproductive Medical Hospital affiliated to Shandong University, No, 157 Jing Liu Street, Shizhong district, Jinan 250001, China. chenzijiang@hotmail.com.
authors.forename: Zi-Jiang
authors.initials: ZJ
authors.lastname: Chen
mesh_terms: D002681:China; D002985:Clinical Protocols; D015925:Cryopreservation; D004624:Embryo Transfer / Q000379:methods*; D005260:Female; D005298:Fertility; D005307:Fertilization in Vitro; D006801:Humans; D007247:Infertility, Female / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D050498:Live Birth; D011085:Polycystic Ovary Syndrome / Q000150:complications*; D011247:Pregnancy; D011446:Prospective Studies; D012107:Research Design; D020554:Sperm Injections, Intracytoplasmic; D016896:Treatment Outcome