title: Reduced Ectopic Pregnancy Rate on Day 5 Embryo Transfer Compared with Day 3: A Meta-Analysis.
abstract: OBJECTIVE
  To compare the risk of ectopic pregnancy (EP) after embryo transfer on day 3(D3-ET) and day 5(D5-ET).
  
  
  METHODS
  Meta-analysis.
  
  
  METHODS
  Women with pregnancy resulting from in vitro undergoing in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI).
  
  
  RESULTS
  Twenty-two studies were identified through research conducted using the PubMed, Embase, and Cochrane databases and ClinicalTrials.gov. All studies were conducted prior to October 2016. Adding the reproductive data from our center, a total of 143 643 pregnancies were reviewed(D3-ET: n = 62027,D5-ET:n = 81616). A lower EP rate was found in women undergoing D5-ET than in those undergoing D3-ET [relative risk (RR), 0.67;95% confidence interval (CI), 0.54-0.85;143643 pregnancies in 23 studies; I2 = 67%]. These results were validated in subgroups of fresh embryo-transfer (Fre-ET) cycles [RR, 0.78; 95%CI, 0.69-0.88; 91 871 pregnancies in 21 studies; I2 = 29%] and frozen-thawed embryo-transfer (Fro-ET) cycles [RR, 0.43; 95%CI, 0.36-0.51; 51 772 pregnancies in 10 studies; I2 = 33%]. After separating out the randomized controlled trials (RCTs), a significant difference was found in the retrospective studies in both subgroups [both Fre-ET (RR,0.78;95% CI 0.69-0.88);91182 pregnancies in 14 studies; I2 = 45%] and Fro-ET(RR,0.43;95% CI 0.36-0.51; 51751pregnancies in 9 studies;I2 = 33%)], while the RCTs showed no statistical significance for Fre-ET cycles[RR,0.86;95% CI 0.32-2.26); 689 pregnancies in 7 studies; I2 = 0%].
  
  
  CONCLUSIONS
  The present study indicates that D5-ET reduces the risk for EP in cycles that use IVF or ICSI, compared with D3-ET. It suggests that D5-ET may be a better choice for decreasing the EP rate in assisted reproductive technology. Further high-quality randomized controlled trials are anticipated.
authors.affiliation: Center for Reproductive Medicine, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China.|National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China.|The Key laboratory of Reproductive Endocrinology (Shandong University), Ministry of Education, Jinan, China.
authors.forename: Bingqian
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Center for Reproductive Medicine, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China.|National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China.|The Key laboratory of Reproductive Endocrinology (Shandong University), Ministry of Education, Jinan, China.
authors.forename: Linlin
authors.initials: L
authors.lastname: Cui
authors.affiliation: Center for Reproductive Medicine, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China.|National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China.|The Key laboratory of Reproductive Endocrinology (Shandong University), Ministry of Education, Jinan, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Tang
authors.affiliation: Center for Reproductive Medicine, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China.|National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China.|The Key laboratory of Reproductive Endocrinology (Shandong University), Ministry of Education, Jinan, China.
authors.forename: Lingling
authors.initials: L
authors.lastname: Ding
authors.affiliation: Center for Reproductive Medicine, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China.|National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China.|The Key laboratory of Reproductive Endocrinology (Shandong University), Ministry of Education, Jinan, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Yan
authors.affiliation: Center for Reproductive Medicine, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China.|National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China.|The Key laboratory of Reproductive Endocrinology (Shandong University), Ministry of Education, Jinan, China.|Center for Reproductive Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.|Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai, China.
authors.forename: Zi-Jiang
authors.initials: ZJ
authors.lastname: Chen
mesh_terms: D004624:Embryo Transfer / Q000009:adverse effects / Q000379:methods*; D005260:Female; D005307:Fertilization in Vitro / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D015994:Incidence; D011247:Pregnancy; D018873:Pregnancy Rate; D011271:Pregnancy, Ectopic / Q000453:epidemiology* / Q000209:etiology; D012307:Risk Factors; D013997:Time Factors