Evaluation of a codesigned resource about in-vitro fertilisation add-ons: an online, parallel-group, single-blinded, randomised trial

Background In-vitro fertilisation (IVF) add-ons are adjuncts to IVF that are usually used with the hope of increasing the chance of IVF success. Prominent information sources for patients, including IVF clinic websites and social media, often contain misleading information about add-ons, overstating potential benefits and omitting information about risks and cost. The aim of this study was to codesign an evidence-based resource about IVF add-ons, and to evaluate its acceptability and effect on patients' understanding of the evidence through an online randomised trial. Methods In a parallel-group, single-blinded, randomised trial, Australian patients undergoing IVF were recruited via social media between March 19 and April 6, 2025, and randomly assigned them to view the new resource or control content generated from synthesising information from high-ranking Google search results. Participants were randomly assigned centrally (1:1:1:1:1:1) using the randomisation function within Qualtrics software, to receive study or control information regarding one of three add-ons (EmbryoGlue, intralipid infusion, or endometrial receptivity testing). Three add-ons were selected to represent different evidence scenarios: evidence of benefit (EmbryoGlue); unclear evidence (intralipid infusion); and evidence of no benefit (endometrial receptivity testing). The primary outcome was gist comprehension measured using a five-item questionnaire that assessed participants' understanding of the effect of these IVF add-ons on the chance of pregnancy, miscarriage, and live birth, the quality of the evidence, and possible side-effects (range 0–10). The analysis was conducted using pooled data from the three add-on groups. Analyses were performed following the intention-to-treat principle, including all randomly assigned participants, with multiple imputation for missing data. The trial was prospectively registered on ClinicalTrials.gov (NCT06885151). Findings 1217 eligible participants were randomly assigned (606 to the evidence-based website group and 611 to the control group, with 899 (74%) providing outcome data. Most participants were women (1202 [99%]), aged 31–40 years (869 [71%]), had undergone IVF previously (1076 [88%]) and were planning future IVF treatment (1156 [95%]). Mean gist comprehension was substantially higher in the evidence-based website group (6·1 [SD 3·0] vs the control group of 2·2 [2·4]; mean difference 3·8 [95% CI 3·5–4·2]; standardised mean difference 1·42 [95% CI 1·27–1·57]; p<0·0001). Interpretation The evidence-based IVF website improved patients' understanding of the benefits, risks, and evidence quality of IVF add-ons, compared with typical online information about these add-ons. This resource should be used by patients and clinicians to support informed decision making about add-on use.