Impact of post-warming culture duration on clinical outcomes of vitrified good-quality blastocyst transfers: a prospective randomized study


      To determine whether post-warming culture duration (1 hour vs. 18 hours) influences implantation rates (IRs) of good-quality blastocysts (GQB) in a good-prognosis population.


      Prospective interventional randomized study.


      University hospital.


      One hundred sixty-two GQB transfers.


      Patients’ vitrified blastocysts were randomly allocated to group A, warming on the day before transfer (n = 81), or B, warming on the day of transfer (n = 81).

      Main Outcome Measure(s)

      IR, live birth rate, reexpansion degree, and quality after warming and immediately before transfer.


      Quality of the warmed and transferred blastocysts was similar (respectively, 39.1% and 32.7% top quality [≥B4AA/AB/BA] in group A vs. 41.7 and 42.2% in group B). In group A, 14 of 102 blastocysts (12.2%) appeared to be unsuitable for transfer, versus only 1 of 103 (0.9%) in group B, thus leading to an additional warming. As expected, reexpansion degree just before transfer was higher in group A (0.90 vs. 0.70). Likewise, the proportion of hatched blastocysts before transfer was higher after a longer culture period (38.6% in group A vs. 12.7% in group B). IRs were similar (38.0% in group A vs. 36% in group B), as were live birth rates (35.8% in group A vs. 34.6% in group B).


      IRs were not different, whatever the duration of post-warming culture of GQB. Both warming strategies could be applied to good-prognosis patients to optimize the laboratory workflow without any detrimental effect.
      Impacto de la duración del cultivo posterior a la desvitrificación en los resultados clínicos tras la transferencia de blastocistos vitrificados de buena calidad: un estudio prospectivo aleatorizado


      Determinar si la duración del cultivo posterior a la desvitrificación (1 hora vs. 18 horas) influye en la tasa de implantación (IRs) de los blastocistos de buena calidad (GQB) en una población de buen pronóstico.


      Estudio prospectivo aleatorizado intervencionista.


      Hospital Universitario.


      Ciento sesenta y dos (162) GQB transferencias.


      Los blastocistos vitrificados de los pacientes fueron asignados de manera aleatoria al grupo A, desvitrificación el día anterior a la transferencia embrionaria (n = 81), o B, desvitrificación en el día de la transferencia (n= 81).

      Variable principal de resultados(s)

      tasa de implantación (IR), tasa de recién nacido vivo, el grado de re expansión, y la calidad después de la desvitrificación e inmediatamente antes de la transferencia embrionaria.


      La calidad de los embriones desvitrificados y transferidos fue similar (respectivamente, 39,1% y 32,7% en los de calidad máxima [RB4AA/AB/BA] en el grupo A vs. 41,7 y 42,2% en el grupo B). En el grupo A, 14 de los 102 blastocistos (12,2%) parecieron no ser adecuados para la transferencia, versus 1 de los 103 (0.9%) del grupo B, con lo que conllevaba una desvitrificación adicional. Como era de esperar el grado de re expansión justo antes de la transferencia ha sido más alto en el grupo A (0,90 vs. 0,70). Así mismo, la proporción de los blastocistos con hatching antes de la transferencia ha sido mayor después del cultivo largo (38,6% en el grupo A vs. 12,7% en el grupo B). La tasa de implantación fue similar (38,0% en el grupo A vs. 36% en el grupo B), así como la tasa de recién nacido vivo (35,8% en el grupo A vs. 34,6% en el grupo B).


      La IRs no fue diferente, independientemente de la duración del tiempo de cultivo posterior a la desvitrificación en embriones de buena calidad. Ambas estrategias de desvitrificación se podrían aplicar para los pacientes de buen pronostico para optimizar la marcha fluida del laboratorio sin ningún efecto perjudicial.

      Palabras clave

      Blastocisto, vitrificación, duración cultivo tras la desvitrificación, tasa de implantación.

      Key Words

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        • Glujovsky D.
        • Farquhar C.
        • Quinteiro Retamar A.M.
        • Alvarez Sedo C.R.
        • Blake D.
        Cleavage stage versus blastocyst stage embryo transfer in assisted reproductive technology.
        Cochrane Database Syst Rev. 2016; : CD002118
        • Li Z.
        • Wang Y.A.
        • Ledger W.
        • Edgar D.H.
        • Sullivan E.A.
        Clinical outcomes following cryopreservation of blastocysts by vitrification or slow freezing: a population-based cohort study.
        Hum Reprod. 2014; 29: 2794-2801
        • Richter K.S.
        • Ginsburg D.K.
        • Shipley S.K.
        • Lim J.
        • Tucker M.J.
        • Graham J.R.
        • et al.
        Factors associated with birth outcomes from cryopreserved blastocysts: experience from 4,597 autologous transfers of 7,597 cryopreserved blastocysts.
        Fertil Steril. 2016; 106: 354-362
        • Roy T.K.
        • Bradley C.K.
        • Bowman M.C.
        • McArthur S.J.
        Single-embryo transfer of vitrified-warmed blastocysts yields equivalent live-birth rates and improved neonatal outcomes compared with fresh transfers.
        Fertil Steril. 2014; 101: 1294-1301
        • Wirleitner B.
        • Schuff M.
        • Stecher A.
        • Murtinger M.
        • Vanderzwalmen P.
        Pregnancy and birth outcomes following fresh or vitrified embryo transfer according to blastocyst morphology and expansion stage, and culturing strategy for delayed development.
        Hum Reprod. 2016; 31: 1685-1695
        • Cobo A.
        • de los Santos M.J.
        • Castellò D.
        • Gámiz P.
        • Campos P.
        • Remohí J.
        Outcomes of vitrified early cleavage-stage and blastocyst-stage embryos in a cryopreservation program: evaluation of 3,150 warming cycles.
        Fertil Steril. 2012; 98: 1138-1146
        • van Landuyt L.
        • Polyzos N.P.
        • de Munck N.
        • Blockeel C.
        • van de Velde H.
        • Verheyen G.
        A prospective randomized controlled trial investigating the effect of artificial shrinkage (collapse) on the implantation potential of vitrified blastocysts.
        Hum Reprod. 2015; 30: 2509-2518
        • Guerif F.
        • Cadoret V.
        • Poindron J.
        • Lansac J.
        • Royere D.
        Overnight incubation improves selection of frozen-thawed blastocysts for transfer: preliminary study using supernumerary embryos.
        Theriogenology. 2003; 60: 1457-1466
        • Maezawa T.
        • Yamanaka M.
        • Hashimoto S.
        • Amo A.
        • Ohgaki A.
        • Nakaoka Y.
        • et al.
        Possible selection of viable human blastocysts after vitrification by monitoring morphological changes.
        J Assist Reprod Genet. 2014; 31: 1099-1104
        • Ahlström A.
        • Westin C.
        • Wikland M.
        • Hardarson T.
        Prediction of live birth in frozen-thawed single blastocyst transfer cycles by pre-freeze and post-thaw morphology.
        Hum Reprod. 2013; 28: 1199-1209
        • Shu Y.
        • Watt J.
        • Gebhardt J.
        • Dasig J.
        • Appling J.
        • Behr B.
        The value of fast blastocoele re-expansion in the selection of a viable thawed blastocyst for transfer.
        Fertil Steril. 2009; 91: 401-406
        • Kovačič B.
        • Taborin M.
        • Vlaisavljević V.
        Artificial blastocoel collapse of human blastocysts before vitrification and its effect on re-expansion after warming—a prospective observational study using time-lapse microscopy.
        Reprod Biomed Online. 2018; 36: 121-129
        • Gardner D.K.
        • Schoolcraft W.B.
        Culture and transfer of human blastocysts.
        Curr Opin Obstet Gynecol. 1999; 11: 307-311
        • Herbemont C.
        • Sarandi S.
        • Boujenah J.
        • Cedrin-Durnerin I.
        • Sermondade N.
        • Vivot A.
        • et al.
        Should we consider day-2 and day-3 embryo morphology before day-5 transfer when blastocysts reach a similar good quality?.
        Reprod Biomed Online. 2017; 35: 521-528
        • Sifer C.
        • Sermondade N.
        • Dupont C.
        • Poncelet C.
        • Cédrin-Durnerin I.
        • Hugues J.N.
        • et al.
        [Outcome of embryo vitrification compared to slow freezing process at early cleavage stages. Report of the first French birth].
        Gynecol Obstet Fertil. 2012; 40 (French): 158-161
        • Coello A.
        • Meseguer M.
        • Galán A.
        • Alegre L.
        • Remohí J.
        • Cobo A.
        Analysis of the morphological dynamics of blastocysts after vitrification/warming: defining new predictive variables of implantation.
        Fertil Steril. 2017; 108: 659-666
        • Fang C.
        • Yue C.M.
        • Huang R.
        • Wei L.N.
        • Jia L.
        Pregnancy outcomes of blastocysts cultured overnight after thawing.
        Arch Gynecol Obstet. 2016; 293: 1347-1356
        • Sunkara S.K.
        • Siozos A.
        • Bolton V.N.
        • Khalaf Y.
        • Braude P.R.
        • El-Toukhy T.
        The influence of delayed blastocyst formation on the outcome of frozen-thawed blastocyst transfer: a systematic review and meta-analysis.
        Hum Reprod. 2010; 25: 1906-1915
        • Kovalevsky G.
        • Carney S.M.
        • Morrison L.S.
        • Boylan C.F.
        • Neithardt A.B.
        • Feinberg R.F.
        Should embryos developing to blastocysts on day 7 be cryopreserved and transferred: an analysis of pregnancy and implantation rates.
        Fertil Steril. 2013; 100: 1008-1012
        • Desai N.
        • Ploskonka S.
        • Goodman L.
        • Attaran M.
        • Goldberg J.M.
        • Austin C.
        • et al.
        Delayed blastulation, multinucleation, and expansion grade are independently associated with live-birth rates in frozen blastocyst transfer cycles.
        Fertil Steril. 2016; 106: 1370-1378
        • Campbell A.
        • Fishel S.
        • Bowman N.
        • Duffy S.
        • Sedler M.
        • Hickman C.F.
        Modelling a risk classification of aneuploidy in human embryos using noninvasive morphokinetics.
        Reprod Biomed Online. 2013; 26: 477-485
        • Capalbo A.
        • Rienzi L.
        • Cimadomo D.
        • Maggiulli R.
        • Elliott T.
        • Wright G.
        • et al.
        Correlation between standard blastocyst morphology, euploidy and implantation: an observational study in two centers involving 956 screened blastocysts.
        Hum Reprod. 2014; 29: 1173-1181
        • Rodriguez-Purata J.
        • Gingold J.
        • Lee J.
        • Whitehouse M.
        • Slifkin R.
        • Briton-Jones C.
        • et al.
        Hatching status before embryo transfer is not correlated with implantation rate in chromosomally screened blastocysts.
        Hum Reprod. 2016; 31: 2458-2470
        • Chimote N.M.
        • Chimote N.N.
        • Nath N.M.
        • Mehta B.N.
        Transfer of spontaneously hatching or hatched blastocyst yields better pregnancy rates than expanded blastocyst transfer.
        J Hum Reprod Sci. 2013; 6: 183-188