P-186 Embryos developing within the optimal morphokinetic range have a 5% higher chance of leading to a Live birth (LB)
Authors: Díaz Hernández N , Tió Marquina M  C , Guerrero J , Brualla A , Pini P , Wiemer K , Bernabeu A , Bernabeu R , Ten J 
Published: July 2024

Abstract

Study question
Is there an optimal range of morphokinetic parameters that have a higher LB rate, if so what is the percentage of LB improvement?

Summary answer
Optimal embryo development range in morphokinetic parameters was identified in t6, t8, tB, t8-t4 and t8-t2 leading to a 5% improvement in LB.

What is known already
Achieving LB is the main objective in IVF. Traditional embryo assessment based on morphology has drawbacks, with variability among embryologists and limited predictive ability for a single-day assessment.
The emergence of AI in IVF, exemplified by CHLOE-EQ, an embryologist’s tool to register embryo morphokinetics and other parameters, presents a solution. This study investigates whether AI-detected morphokinetic parameters can significantly improve LB rates, providing a more precise and predictive approach to embryo assessment. This study investigates if embryos that lead to LB develop under specific morphokinetic optimal ranges.

Study design, size, duration
Conducted across multiple centres within a private clinic, this retrospective study investigated 7156 embryos with known birth outcome between January 2021 and January 2023.

Participants/materials, setting, methods
Absolute (tPNf to tEB) and interim morphokinetic parameters that have been previously been found to impact embryo development (CC1, CC2, CC3, S2, S3, t5-t2, t8-t4, t8-t2, tEB-tSB) were automatically annotated by an AI model (CHLOE-EQ, Fairtility Ltd). The interquartile range (Q1-Q3) of embryos that resulted in live birth was analyzed to identify the optimal range. Chi-square analysis compared live birth rates between embryos within and outside this range.

Main results and the role of chance
A significant Live birth optimal range was found for t6 (47.8-57.3), t8 (51.8-65.8), tB (100.9-113.6), t8-t4 (15.2-25.5), t8-t2 (26.9-39.2), p &lt; 0.05. The following morphokinetic parameters were associated with higher LB rate when the embryo was within the optimal range hours as compared to outside the optimal range: t6 (38%, n = 1012 vs 35% n = 1007, p &lt; 0.05), t8 (38%, n = 947 vs 35%, n = 941, p &lt; 0.05), tB (33%, n = 548 vs 30%, n = 533, p &lt; 0.05), t8-t4 (38%, n = 926 vs 34%, n = 943, p &lt; 0.05), t8-t2 (38%, n = 938 vs 35% n = 936, p &lt; 0.05). No significant LB rate differences were observed for other morphokinetics. Overall, LB rates improved by 3-5% in embryos developing at the optimal rate, with a slightly higher significance in absolute morphokinetic values over interim ones.

Limitations, reasons for caution
The study’s retrospective nature entails inherent biases. Additionally, this analysis does not account for oocyte origin and male factor as bias elements, which will be considered in future research. Thus results may not be transferrable to clinics that have other clinical practices and different patient demographics.

Wider implications of the findings
Certain morphokinetic parameters can be added to the already existing range of available LB evaluation methods. Future studies should explore diverse morphokinetic ranges to identify additional optimal intervals for each parameter. AI tools can facilitate automatic annotation and measurement of embryo morphokinetics, enhancing precision in assessment.

Trial registration number
Not applicable