O-319 A randomised trial of time-lapse imaging of embryos in in-vitro-fertilisation treatment
Authors: Bhide P 
Published: July 2024

Study question

Do time-lapse imaging (TLI) systems used in IVF/ICSI treatment improve live birth either due to undisturbed culture conditions or improved embryo selection or both?

Summary answer

In women undergoing IVF/ICSI treatment the use of TLI systems does not significantly increase the odds of live birth compared to standard care without TLI.

What is known already

TLI systems used in IVF treatment have the potential to improve fertility outcomes either due to undisturbed culture conditions or improved embryo selection or both.

However, there remains uncertainty about its benefits. Existing reviews and primary studies predominantly report no differences between the use of TLI and conventional methods. However none of the previous trials were adequaltely powered to detect meaningful differences in live birth and the quality of most trials was deemed to be low to very low.

Study design, size, duration

TILT (Time-lapse Imaging Trial) is a multi-centre, three-arm, parallel-group, double-blind, randomised controlled trial. Participants were randomly assigned in a 1:1:1 ratio to the TLI system for both undisturbed culture and embryo selection (TLI arm), TLI system for undisturbed culture conditions alone (undisturbed culture arm), and standard care without TLI (control arm). From June 2018 to September 2022, we randomised 1575 participants based on a pre-specified sample size to detect an 8.75% difference in live births.

Participants/materials, setting, methods

We randomised 1575 couples undergoing IVF/ICSI with broad inclusion criteria across seven IVF centres.

The primary outcome was live birth. Secondary outcomes included clinical pregnancy, pregnancy loss, and multiple pregnancy.

Primary analysis was performed based on the intention-to-treat principle for all participants with primary outcome data available and the effect estimate reported as an adjusted odds ratio (aOR).

Pre-specified sensitivity analyses and subgroup analyses for age and method of embryo transfer were performed.

Main results and the role of chance

We recruited 2191 and randomised 1575 participants.

Live birth data were available for 1558/1575 (98.92%) participants.

The livebirth rates were 33.7% (175/520) in the TLI arm, 36.6% (189/516) in the undisturbed culture arm and 33.0% (172/522) in the control arm.

The aOR was 1.04 (97.5% confidence interval (CI) 0.73 to 1.47) for TLI arm vs control and 1.20 (97.5% CI 0.85 to 1.70) for undisturbed culture vs control.

The clinical pregnancy rates were 42.2% (219/519) in the TLI arm, 43.4% (225/518) in the undisturbed culture arm, and 40.9% (212/519) in the control arm.

There were no significant differences for TLI vs control arm (aOR 1.06, 95% CI 0.82-1.38) and undisturbed culture vs control arm (aOR 1.11, 95% CI 0.86-1.46).

The rates of pregnancy loss between clinical pregnancy and 24 weeks’ gestation were not statistically different when TLI (8.7%, 45/515) and undisturbed culture arms (6.4%, 33/513) were compared with control arm (8.1%, 42/517) with aOR 1.09 (95% CI 0.66-1.77) and 0.76 (95% CI 0.45-1.29) respectively.

None of the other secondary outcomes demonstrated significant differences between the arms

The findings were similar irrespective of the woman’s age and use of fresh or frozen embryo replacement, and for all sensitivity analyses, for primary and secondary outcomes.

Limitations, reasons for caution

Although the trial recruitment was delayed by the SARS-CoV-2 pandemic, this did not impact the results as patient populations, clinical care pathways and time-lapse technology remained similar.

The remit of this trial did not allow assessment of the influence of TLI systems on embryology laboratory workflow or perform a health-economic analysis.

Wider implications of the findings

Our trial provides high-quality definitive evidence of no benefit of the use of TLI systems for embryo incubation and selection to improve success rates in women having IVF and ICSI treatment.

Trial registration number

ISRCTN17792989