P-183 Blastocyst speed versus blastocyst look: Which is the better predictor of clinical pregnancy and live birth following time-lapse culture and single blastocyst transfer?
Authors: Zedeler A , Simonsen K , Liljeqvist Soltic I , Saunders H , Jenkins J , Pinborg A 
Published: June 2023

Abstract

Study question
To compare predictive value for pregnancy and live birth of morphological versus morphokinetic assessment of blastocysts after time-lapse culture and single blastocyst transfer.

Summary answer
Blastocyst morphokinetic assessment was not superior in predicting pregnancy and live birth compared to blastocyst morphology, but provides additional information, particularly for morphologically poorer-quality blastocysts.

What is known already
Blastocyst culture with time-lapse technology enables evaluation of both morphokinetic developmental speed and classical morphology including Gardner scoring of the blastocyst. One approach to assess the developmental speed of blastocysts is to use the morphokinetic classification proposed by Campbell, Fishel, et al., based on time to start of blastulation (tSB) and the duration of forming the blastocyst (dB). However, beyond the advantages of undisturbed embryo culture, the value of the kinetic data from time-lapse is debated.

Study design, size, duration
EDCOS (Embryo Developmental profiles from Controlled Ovarian Stimulation cycles using follitropin alfa) is a multicentre, prospective cohort study of patients undergoing IVF/ICSI whose embryos were cultured in time-lapse incubator devices in 10 ART centres throughout Denmark and Sweden. Patients undergoing IVF/ICSI (including donor oocyte cycles) who had ovarian stimulation with follitropin alfa (Bemfola®) and had zygotes and embryos available for monitoring in the EmbryoScope™ time-lapse incubator device (Vitrolife) were invited to join this study.

Participants/materials, setting, methods
Morphological and morphokinetic prognostic classifications for single blastocyst transfers (SET) were determined for three study subpopulations: fresh autologous SET (311 women), frozen autologous SET (246 women; 345 transfers) and frozen donor SET (38 women; 59 transfers). All blastocysts were graded morphologically in five grades from Amorph (best) to Emorph (worst) based on their Gardner score and morphokinetically in three grades from Akin (best) to Ckin (worst) based on tSB and dB.

Main results and the role of chance
Overall ongoing pregnancy and live birth rates (OPR/LBR) for morphokinetic classifications Akin, Bkin and Ckin were 36.1%, 30.0% and 16.3% (P = 0.021) and 30.4%, 21.8% and 9.1% (P = 0.000), respectively. OPR and LBR for morphological classifications Amorph, Bmorph, Cmorph, Dmorph and Emorph were 41.9%, 37.8%, 30.8%, 19.0% and 15.6% (P = 0.000) and 36.6%, 29.1%, 15.6%, 16.5% and 8.3% (P = 0.002), respectively. For Dmorph blastocysts, OPR and LBR for morphokinetic classifications Akin, Bkin and Ckin were 50%, 21.4% and 7.1% (P = 0.009) and 33.3%, 10.8% and 0% (P = 0.003), respectively. Receiver operating characteristic curve analyses achieved areas under the curve for fresh autologous SET of 55.7%, 58.9% and 67.2% for the morphokinetic, morphological and combined classifications, respectively; and 53.4%, 64.0% and 65.6%, respectively, for frozen autologous SET.

Limitations, reasons for caution
This was an observational study with no control group, conducted under usual clinical practice. Data were collected prospectively, although clinics could deselect and rank blastocysts according to their own procedures. However, the outcome of subsequent frozen blastocyst transfer cycles was also analysed.

Wider implications of the findings
Selection of a blastocyst for transfer based on morphokinetic assessment at the blastocyst stage was not superior to classical blastocyst morphological assessment after time-lapse culture but is a viable option. Combining morphokinetic and morphological evaluation provides additional supporting information to guide in blastocyst selection, especially for morphologically poorer-quality blastocysts.

Trial registration number
Not applicable