P-741 Morphokinetic Goldilocks: assessing the morphokinetic range to identify embryos with the optimal chance of being euploid
Authors: Sharma S , Doshi A , Bhatia C , Zepeda A , Brualla A , Hickman C 
Published: June 2023

Abstract

Study question
Can CHLOE-EQ, an AI embryo assessment support tool, automatically identify the optimal time-range of morphokinetic events where chance of euploidy is maximized?

Summary answer
Embryos that are within the normal morphokinetic range have increased chances of being euploid compared to embryos developing at a pace outside the optimal range.

What is known already
The introduction of time-lapse technologies in IVF has revealed quantitative and qualitative morphokinetic parameters that predict embryo viability (ESHRE Workshop group, 2020), but their assessment is time-consuming and subjective. Artificial Intelligence (AI) based tools, such as CHLOE-EQ (Fairtility), are ideally suited to automatically annotate morphokinetics as part of a range of tools to quantify embryo quality and detect abnormalities. There have been several attempts in the literature to predict ploidy with morphokinetics. We postulated that embryos that develop at a normal pace (not too fast and not too slow) would be more likely to be euploid.

Study design, size, duration
Retrospective case-controlled study of 1328 time-lapse videos collected in 2022 from IVF and ICSI embryos from a private single fertility clinic. 142 of those were biopsied and genetically tested by NGS. The embryos were automatically assessed by CHLOE-EQ (Fairtility), an AI embryologist support tool.

Participants/materials, setting, methods
Time-lapse videos were automatically annotated using CHLOE-EQ(Fairtility) for morphokinetics, number of pronucleates and anomalies. The frequency distribution for each morphokinetic parameter was compared between euploid and aneuploid embryos to establish ranges for optimal euploidy rate. The ranges between optimal (maximum euploidy rate) and sub-optimal (outside optimal range) were compared (t-test). Efficacy of blastocyst, utilisation and ploidy prediction by CHLOE blast score at 68hpi and CHLOE-EQ score were assessed using the area under the curve (AUC).

Main results and the role of chance
For each morphokinetic event, an optimal range for identification of euploids was identified (tPNf:21.37-25.78; t2:24.01-28.6; t3:34.07-39.20; t4:35.5-40.64; t5:46.12-53.92; t6:48.77-55.63; t7:50.22-57.45; t8:52-60.21; t9:67.35-75.55; tM:78.49-89.08; tsB:92.20-102.39; tB:99.54-109.83; tEB:106.42-120.38). Optimal range of euploid embryos was smaller than the total range for all embryos (p &lt; 0.001): tPNf (0.27 vs 152.36), t2(5.52 vs 158.96), t3(22.7 vs 159.29), t4(30.38 vs 167.96), t5(32.02 vs 168.29), t6(35.58 vs 155.44), t7(41.04 vs 157.65), t8(41.37 vs 158.06), t9(48.85 vs 158.39), tM(56.4 vs 163.89), tSB(84.74 vs 173.26), tB(93.01 vs 168.62); tEB(95.96 vs 164). Embryos with optimal ranges across morphokinetic events had a higher euploidy rate than embryos with suboptimal ranges [50% (11/20), 35.35% (35/99), NS].
CHLOE-BLAST Score at 68hpi was predictive of blastulation (AUC=0.86), whilst CHLOE-EQ Score was predictive of utilisation (AUC 0.88) and euploidy (AUC=0.64) and CHLOE Ranking was predictive of utilisation (AUC=0.91) and selection for transfer (AUC=0.80).

Limitations, reasons for caution
This is a single-center, retrospective study, where only the blastocysts deemed suitable for biopsy were assessed for ploidy. Therefore, the ploidy rate of non-blastocysts or inferior quality embryos is unknown, creating a potential bias regarding the lower cutoff threshold for optimal ranges.

Wider implications of the findings
CHLOE-EQ can identify the optimal morphokinetic time range to maximise the chance of an embryo being euploid, a potentially valuable biomarker for embryo assessment, selection, managing patients expectations down to individual embryos, and helping reduce the chance of viable embryos being discarded.

Trial registration number
Not applicable