Time-lapse imaging systems for embryo incubation and assessment to improve reproductive outcomes in women undergoing in vitro fertilisation: study protocol for an individual participant data meta-analysis of randomised controlled trials.

INTRODUCTION: Time-lapse imaging (TLI) systems for embryo incubation and assessment are hypothesised to improve the success rates of in vitro fertilisation (IVF) treatment by providing undisturbed culture conditions for embryos and/or providing more information on embryo development (morphokinetic parameters) to improve predictive accuracy for embryo selection. Despite numerous aggregate meta-analyses showing uncertainty of benefit, IVF clinics globally continue to invest significant resources into this technology with little translation of evidence into guidelines or policy frameworks. This may be attributed to heterogeneity in participant populations and/or variations in the use of TLI, as highlighted in the aggregate meta-analyses.

METHODS AND ANALYSIS: Our research proposal for evidence synthesis using individual participant data meta-analysis will provide greater power than aggregate meta-analysis to detect differential treatment effects for effectiveness (live birth, clinical pregnancy) and safety (pregnancy loss, multiple births, congenital malformations) outcomes across three comparisons (overall effect, undisturbed culture and morphokinetic parameters). We will also analyse if there are specific subgroups of women who may benefit from the intervention and if variations in use of the intervention show any benefits. We have incorporated the results of the literature search used for the latest Cochrane review (7 January 2019) into this review and will include all the trials included therein. We will further update the literature search to include new evidence by searching the electronic databases MEDLINE, EMBASE, CINAHL and CENTRAL from 07/01/2019 to date, outcomes for all ongoing trials reported in the 2019 Cochrane review, trial registers for newer ongoing/completed trials and the citation lists of all the newly identified trials for any relevant references. The search strategy will include a combination of subject headings and text words relating to or describing the participants and the intervention, with no language restrictions. Two authors will independently screen the titles and abstracts, and full text of articles retrieved from the search, to finalise a list of trials suitable for inclusion in the review. We will include randomised controlled trials that assess TLI systems for either undisturbed culture and/or use of morphokinetic parameters for embryo selection in women having IVF/ICSI treatment using their own oocytes.

ETHICS AND DISSEMINATION: Ethical approval is not required for this study. We plan to disseminate the findings of the research to all stakeholders, including the National Institute for Health and Care Excellence and other international guideline development groups, through publication in peer-reviewed journals, presentation at conferences, newsletters, meetings and websites of the funders, fertility charities and patient support groups.

PROSPERO REGISTRATION NUMBER: CRD42024564332.