Table 2. Summary of the studies highlighting the morphokinetic variables with statistically significant differences.
Item Reference Type of study Embryos
(n)		 Patients
(n)		 Embryo culture Day transfer Morphokinetic parameters Statistically significant
variables
significant difference no significant difference
Young vs Older Hickman et al., 2013 Retrospective 348 NA Blastocyst stage NA x   tM, tEB,tHed
Silva et al., 2015 Retrospective 288 76 Blastocyst stage NA x   tM,tSB,tB,tEB
Akarsu et al., 2017 Retrospective 1144 197 Cleavage stage d3 X   tPNf,t2,t3,t4
Dal Canto et al., 2021 Retrospective 4915 1066 Cleavage stage d2/d3 X   tPNf,t2,t3,t4 ,t8
Gryshchenko et al., 2014 Prospective 262 616 Cleavage/Blastocyst stage d3/d5   X  
Warshaviak et al., 2019 Retrospective 1148 122 Cleavage stage d3   X  
BMI Bartolacci et al., 2019 Retrospective 7180 1528 Cleavage/Blastocyst stage d3/d5 X   t5,t8
Bellver et al., 2013 Retrospective 424 89 Blastocyst stage d3 X   t2,t3,t4 and t5
Lammers et al., 2013 Retrospective NA 366 Cleavage stage NA X   t4,t5,t8
Leary et al., 2015 Retrospective 155 29 Blastocyst stage d3/d5 X   tM
Mumusoglu et al., 2017 Retrospective 415 103 Blastocyst stage NA X   tPN,tPNf,t2,t4,t5,t6,t7,t8,s2
Silva et al., 2015 Retrospective 288 76 Blastocyst stage NA   X  
PCOS  vs non PCOS Chappel et al., 2017 Retrospective 1108 86 Blastocyst stage NA X   t7,t8,t9,tM
Chappell et al., 2020 Retrospective 1618 256 Blastocyst stage NA X   t5,t6,t7,t8,t9, tSC
Sundvall et al., 2015 Prospective 1388 217 Blastocyst stage d6 X   tSC, tM and t5-t4
Tabibnejad et al., 2019 Prospective 547 100 Cleavage stage d3 X   tPNf,t2,t3,t4,t5,t6,t7,t8
Tam Le et al., 2019 Prospective 851 106 Cleavage stage d2   X  
Wissing et al., 2014 Prospective 347 71 Blastocyst stage d2 X   tPNf,t2,t3,t4,t7
Endometriosis Boynukalin et al., 2019 Retrospective 439 NA Cleavage stage NA X   tPB,tPN,cc1,s2
Freis et al., 2018 Retrospective 477 168 Blastocyst stage NA X   cs2-8 = ((t3-t2)+(t5-t4))/(t8-t2)) cs4-8 =  (t8-t5)/(t8-t4)
Schenk et al., 2019 Retrospective 1148 163 NA d3/d4/d5 X   s2, t9
Smoking habitus Fréour et al., 2013 Retrospective 485 135 Cleavage/Blastocyst stage d3/d5 X   t3,t4,t5
Siristatidis et al., 2015 Prospective NA 239 Cleavage stage d2/d3 X   cc2, S2
Single vs. sequential media Basile et al., 2013 Prospective 532 75 Cleavage stage d3   X  
Ciray et al., 2012 Prospective 319 51 Blastocyst stage d3/4/5 X   tPNf,t2,t3,t4,t5
Costa-Borges et al., 2016 Prospective 628 59 Blastocyst stage d5   X  
Hardarson et al., 2015 Prospective 1356 128 Blastocyst stage d3/5/6 X   t7,t8, cc2
VF vs. ICSI Bodri et al., 2015 Retrospective 1285 209 Blastocyst stage d5 X   tBE
Cruz et al., 2013 Retrospective 1203 178 Blastocyst stage d3/5   X  
Dal Canto et al., 2012 Retrospective 459 NA Blastocyst stage d3/5 X   t2, t3
Kim et al., 2017 Cohort study 1830 NA Blastocyst stage NA X   tPNf,t1,t2,t3,t4,t5, t6
Lemmen et al., 2008 Cohort study 102 NA Cleavage stage d2 X   t2
Oxygen 5% vs. 20% Kirkegaard et al., 2013a Retrospective 363 84 Blastocyst stage NA X   s3

Note: NA: not available; d2/3/5: day 2/3/5; other abbreviations in Table 1.