title: Morphokinetic parameters using time-lapse technology and day 5 embryo quality: a prospective cohort study.
abstract: OBJECTIVE
  The aims of this prospective study were to evaluate whether time-lapse parameters can aid in the prediction of day 5 embryo quality and also to assess their discriminatory capacity.
  
  
  METHODS
  In this prospective cohort study, we used time-lapse technology to record specific timings of key events for 380 day 5 blastocysts (originating from 108 patients). Generalized estimating equation regression models were used to evaluate the capacity of these markers to identify a top-quality blastocyst. Multivariable regression models were also constructed, aiming to identify the model with the highest capacity to predict a top-quality blastocyst. The discriminatory capacity of single predictors or composite models was assessed with the use of receiver operating characteristic (ROC) analyses.
  
  
  RESULTS
  Eight significant predictive parameters of a top-quality blastocyst were identified: s3, t6, t7, t8, tM, tSB, tB and tEB. A ROC analysis of the identified parameters found s3 (area under the curve--AUC 0.585, 95 % CI 0.534-0.635) to have the best individual discriminatory capacity to predict a top-quality blastocyst prior to embryo compaction. The parameter tEB (AUC 0.727, 95 % CI 0.675-0.775) was the best predictor regardless of embryo stage. A model containing s3, t8 and tEB showed a slightly increased discriminatory capacity for top-quality blastocyst prediction (AUC 0.748, 95 % CI 0.697-0.794).
  
  
  CONCLUSIONS
  The identified morphokinetic parameters and their cutoffs, albeit of limited clinical value, add to the increasing knowledge concerning the potential predictive markers of a top-quality blastocyst. Additional evidence is necessary before validated time-lapse parameters can be used for embryo selection in IVF laboratories.
authors.affiliation: IVF Australia Western Sydney, Level 2, 20-22 Mons Road, Westmead, NSW, 2145, Australia, ashleigh_storr@hotmail.com.
authors.forename: Ashleigh
authors.initials: A
authors.lastname: Storr
authors.forename: Christos A
authors.initials: CA
authors.lastname: Venetis
authors.forename: Simon
authors.initials: S
authors.lastname: Cooke
authors.forename: Daisy
authors.initials: D
authors.lastname: Susetio
authors.forename: Suha
authors.initials: S
authors.lastname: Kilani
authors.forename: William
authors.initials: W
authors.lastname: Ledger
mesh_terms: D000328:Adult; D019540:Area Under Curve; D001755:Blastocyst / Q000166:cytology / Q000502:physiology*; D015331:Cohort Studies; D015925:Cryopreservation; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D008423:Maternal Age; D008875:Middle Aged; D010062:Ovulation Induction; D011247:Pregnancy; D018873:Pregnancy Rate; D011446:Prospective Studies; D012044:Regression Analysis; D015203:Reproducibility of Results; D020554:Sperm Injections, Intracytoplasmic; D059008:Time-Lapse Imaging / Q000379:methods*